Temperature-sensitive color-changing intelligent temperature-regulating heat-insulating coating as well as preparation and application thereof

Abstract

The invention discloses a temperature-sensitive color-changing intelligent temperature-regulating and heat-insulating coating as well as preparation and application thereof, and belongs to the technical field of heat-insulating materials. The invention relates to a temperature-sensitive color-changing intelligent temperature-adjusting heat-insulating coating, which comprises the following components by mass: 60-80 parts of acrylic acid modified polyurethane resin; 10 to 15 parts of a temperature-sensitive color-changing microcapsule; 6-10 parts of a phase change energy storage microcapsule; 5-8 parts of VO2 (W)-TiO2 composite particles, the particle size of which is 30-80 nm; 0.5 part to 1.0 part of a light stabilizer HALS-770; 1.0 to 2.0 parts of a dispersant sodium dodecyl benzene sulfonate; 0.3 to 0.6 part of a rheological auxiliary agent, namely organic bentonite; and mixing solvents. The cholesteric liquid crystal temperature-sensitive microcapsules, the phase change energy storage microcapsules and the doped VO2 thermal control nanoparticles are compounded and integrated in the same coating system, so that the synergistic temperature control effect of color change indication, phase change buffering and infrared reflection is realized.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation coating technology, and more specifically, to temperature-sensitive color-changing intelligent temperature-regulating thermal insulation coatings and their preparation and application. Background Technology

[0002] With the increasing severity of global warming and the urban heat island effect, how to effectively achieve passive temperature regulation and thermal management of buildings and equipment has become an important direction for energy-saving and environmental protection technology research. Traditional thermal insulation coatings usually rely on high-reflectivity pigments (such as TiO2 and ZnO) or low-thermal-conductivity fillers (such as hollow microspheres and aerogels) to achieve thermal barrier effects. Although they can effectively reduce heat conduction or radiation absorption in the initial stage, their functions are limited, they lack active regulation capabilities, and they are difficult to adapt to complex and variable climatic environments.

[0003] In recent years, research on intelligent responsive functional materials has gradually emerged, especially in the fields of thermochromic materials, phase change energy storage materials, and thermally controlled nanoparticles (such as VO2), where breakthroughs have been achieved. For example, cholesteric liquid crystals can undergo an ordered-disorder phase transition according to temperature changes, exhibiting a significant optical color-changing effect; phase change materials can maintain a constant temperature during heat absorption or release, effectively mitigating temperature fluctuations; and doped VO2 materials possess temperature-controlled infrared reflection characteristics, undergoing a crystal phase transition at specific temperatures to alter the reflectivity to near-infrared radiation from the sun. These functional materials offer possibilities for the intelligent development of temperature-controlled coatings.

[0004] However, existing smart coatings based on the above materials still face the following prominent technical problems:

[0005] Single function and weak response mechanism: Many studies focus only on a single temperature control mechanism (such as color change or phase change) and lack the ability to control multiple functions, resulting in low overall temperature control efficiency.

[0006] Poor stability and rapid functional decay: Liquid crystal or phase change materials are prone to migration, leakage and failure under high humidity and high temperature conditions, and lack long-term environmental tolerance.

[0007] Weak microstructure control capability: lack of precise design of color-changing material particle size, phase change material encapsulation structure and VO2 particle recombination mode, making it difficult to achieve synergistic optimization of response temperature range, spectral range and mechanical properties;

[0008] The preparation process is complex and has poor repeatability: existing coating preparation processes often involve multiple manual mixing steps, resulting in uneven emulsification or coating, making it difficult to achieve stable batch preparation. Summary of the Invention

[0009] The purpose of this invention is to provide a temperature-sensitive color-changing intelligent temperature-regulating and heat-insulating coating, its preparation and application, in order to solve the problems raised in the background art.

[0010] A thermosensitive color-changing intelligent temperature-regulating and heat-insulating coating, comprising the following components by weight:

[0011] (1) Acrylic modified polyurethane resin, 60-80 parts, used as a coating film matrix, which has both flexibility and weather resistance;

[0012] (2) Thermosensitive color-changing microcapsules, 10-15 parts, with cholesteric liquid crystal as the core material and polymethyl methacrylate as the wall material, used for thermosensitive color change and reflectivity adjustment;

[0013] (3) Phase change energy storage microcapsules, 6-10 parts, the core material is cetyl alcohol (melting point is about 58℃), and the wall material is modified nano SiO2, which is used to absorb and release heat to achieve local temperature control buffering;

[0014] (4) VO2(W)-TiO2 composite particles, 5-8 parts, with a particle size of 30-80nm, have thermally induced phase transition characteristics. They undergo a transition from a metallic state to a semiconductor state at a critical temperature of 68℃, resulting in a dramatic increase in infrared reflectivity.

[0015] (5) Light stabilizer HALS-770, 0.5-1.0 parts, used to improve UV aging resistance;

[0016] (6) Sodium dodecylbenzenesulfonate dispersant, 1.0-2.0 parts, used to improve the stability of nanoparticles and microcapsules in the system;

[0017] (7) Rheology modifier organic bentonite, 0.3-0.6 parts, used to regulate the fluidity and thixotropic properties of coatings and improve their adaptability to construction;

[0018] (8) Mixed solvent, 10-20 parts, to provide a suitable evaporation rate and balanced polarity.

[0019] Preferably, the preparation method of the thermosensitive color-changing microcapsules includes the following steps:

[0020] Step 1: Mix the cholesteric liquid crystal component with dibutyl phthalate (DBP) plasticizer in a 3:1 ratio to form an oil phase;

[0021] Step 2: Combine polymethyl methacrylate, polyvinyl alcohol, and water to form an aqueous phase;

[0022] Step 3: The oil phase and the water phase are mixed and emulsified in a high-speed shear machine at a shear rate of 12,000 rpm for 5 minutes;

[0023] Step 4: Maintain the temperature at 50℃ for 8 hours for free radical polymerization, then cool, centrifuge, wash with water and dry to obtain microcapsule particles with a particle size of 1-3μm and a coating rate of ≥80%.

[0024] The microcapsule undergoes a birefringence transition due to changes in its liquid crystal structure within the temperature range of 25-35℃, achieving a color change from dark gray to milky white, accompanied by an increase in visible light and near-infrared reflectivity.

[0025] Preferably, the cholesteric liquid crystal is a mixture of cholesterol caprylate and cholesterol stearate in a mass ratio of 1:1 to 3:1, and has the following characteristics:

[0026] Cholesteric liquid crystals are molecular stacked systems with right-handed helical arrangement. Their pitch changes reversibly within a temperature range of 25-40℃, thereby modulating the selective reflection band of visible light.

[0027] Cholesterol caprylate has a melting point of approximately 36°C, and cholesterol stearate has a melting point of approximately 42°C. When the two are mixed, they form a thermochromic material with a wide response range.

[0028] Preferably, the preparation method of the phase change energy storage microcapsules is as follows:

[0029] Step 1: Heat cetyl alcohol to 70°C to melt it;

[0030] Step 2: Add silane coupling agent KH-560, tetraethyl orthosilicate, and a small amount of ammonia to form a sol in ethanol medium;

[0031] Step 3: Use interfacial polycondensation + emulsification to coat the cetyl alcohol with a stirring rate of 6000 rpm, a reaction temperature of 40°C, and a reaction time of 6 hours.

[0032] Step 4: Centrifuge, wash, and dry to obtain spherical microcapsules.

[0033] Cetyl alcohol melts and absorbs heat when the temperature rises, effectively delaying changes in the internal surface temperature, enhancing the response inertia to changes in heat flow, and improving temperature regulation performance.

[0034] Preferably, the preparation method of the VO2(W)-TiO2 composite particles is as follows:

[0035] Step 1: Dissolve ammonium vanadate and sodium tungstate in deionized water at a molar ratio of 10:1, and add citric acid as a complexing agent;

[0036] Step 2: Set the hydrothermal reaction temperature to 180℃ and cool after reacting for 12 hours.

[0037] Step 3: Mix with nano TiO2 at a 1:1 mass ratio and ball mill for 30 minutes using high energy.

[0038] Step 4: Calcine at 550°C for 2 hours in an argon atmosphere to obtain tungsten-doped VO2 (TiO2) thermal control particles.

[0039] The critical temperature of this material is about 58-65℃. When the temperature exceeds this, a crystal transformation occurs, which increases the infrared reflectivity from 20% to more than 80%, effectively blocking solar heat radiation.

[0040] Preferably, the coating preparation method includes the following steps:

[0041] S1. Thermosensitive color-changing microcapsules, phase change energy storage microcapsules and VO2(W)-TiO2 composite particles are prepared according to the methods of claims 2 to 5 respectively.

[0042] S2. Add VO2(W)-TiO2 composite particles and phase change energy storage microcapsules to the resin and disperse them in an ultrasonic disperser for 15 minutes.

[0043] S3. Add the temperature-sensitive microcapsules, light stabilizer, dispersant, and rheology modifier in sequence, and stir for 30 minutes until the system is homogeneous;

[0044] S4. Add the mixed solvent to dilute to the application viscosity, filter, and then package.

[0045] Preferably, it has application value in the following fields:

[0046] Building exterior wall and roof insulation system, suitable for energy-saving buildings in hot-summer and cold-winter regions;

[0047] Photovoltaic module backsheets are used to reduce the decrease in electrical efficiency caused by temperature rise.

[0048] Surfaces of industrial equipment with high thermal management requirements, such as energy storage devices, transformer substations, and vehicle shells.

[0049] Compared with the prior art, the advantages of this invention are:

[0050] (1) This invention integrates cholesteric liquid crystal thermosensitive microcapsules, phase change energy storage microcapsules, and doped VO2 thermal control nanoparticles into the same coating system, achieving a synergistic temperature control effect of color change indication, phase change buffering, and infrared reflection. Among them, the cholesteric liquid crystal material can undergo reversible color change within a specific temperature range (20-45℃), providing visual response and local heat dissipation regulation; the phase change material effectively reduces temperature peak-valley fluctuations by absorbing or releasing latent heat; and the VO2 particles undergo rapid phase transformation near the critical temperature, improving the reflectivity to near-infrared thermal radiation and reducing the heat load.

[0051] (2) The present invention encapsulates liquid crystal and phase change material respectively using microcapsule encapsulation technology, effectively inhibiting their volatilization, leakage, oxidation and migration behavior, significantly improving the stability and durability of the coating under extreme environments such as high humidity, high temperature and ultraviolet irradiation, and extending service life. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0053] Example 1:

[0054] Step 1: Preparation of thermosensitive color-changing microcapsules: Weigh 20g of cholesterol caprylate and 10g of cholesterol stearate, and add 10g of dibutyl phthalate (DBP) as a plasticizer;

[0055] Heat to 60℃ and stir until homogeneous to form a transparent oil phase;

[0056] Preparation of the aqueous phase: Take 100 mL of deionized water, add 3 g of polyvinyl alcohol (PVA), and stir until completely dissolved;

[0057] In a shear emulsifier, the oil phase is slowly dripped into the aqueous phase at a speed of 12,000 rpm for 5 minutes;

[0058] Maintaining the temperature at 50℃, 10 mL of methyl methacrylate (MMA) monomer and 0.5 g of benzoyl peroxide initiator were added dropwise under nitrogen protection.

[0059] After polymerization for 8 hours, the mixture was cooled, centrifuged and washed three times, and then dried to obtain thermosensitive color-changing microcapsules with a particle size of approximately 2 μm.

[0060] Step 2: Preparation of phase change energy storage microcapsules: Weigh 80g of hexadecyl alcohol into a beaker and heat to 70℃ to melt;

[0061] Prepare a separate sol: Add 20g of tetraethyl orthosilicate, 2g of KH-560 and 1mL of ammonia to 200mL of ethanol, and stir for 30 minutes;

[0062] Slowly add the sol solution dropwise into the melted cetyl alcohol, stir rapidly and sonicate for 10 minutes;

[0063] Microcapsules were formed by continuous stirring in a 40°C water bath for 6 hours.

[0064] After cooling, the microcapsules were centrifuged and washed three times, and then vacuum dried to obtain white phase change energy storage microcapsules with a particle size of about 500 nm.

[0065] Step 3: Preparation of VO2(W)-TiO2 composite particles: Dissolve 80g of ammonium vanadate and 10g of sodium tungstate in 300mL of deionized water;

[0066] Add 10g of citric acid as a complexing agent and adjust the pH to 4.5;

[0067] Transfer to a high-pressure reactor and hydrothermally react at 180°C for 12 hours;

[0068] The product was washed and dried, then mixed with TiO2 at a mass ratio of 1:1 and ball-milled for 30 minutes.

[0069] The VO2(W)-TiO2 composite particles were obtained by calcination at 550℃ for 2 hours in an argon atmosphere, followed by cooling and grinding.

[0070] Step 4: Preparation of the main coating system: Weigh 70g of acrylic modified polyurethane resin, 12g of thermosensitive color-changing microcapsules, 8g of phase change energy storage microcapsules, and 6g of VO2(W)-TiO2 composite particles.

[0071] VO2(W)-TiO2 composite particles and phase change energy storage microcapsules were added to the resin and ultrasonically dispersed for 10 minutes.

[0072] Add the thermosensitive color-changing microcapsules and continue stirring for 15 minutes;

[0073] Add the following ingredients in sequence: HALS-770 light stabilizer 0.6g, sodium dodecylbenzenesulfonate 1.5g, and organobentonite 0.4g;

[0074] Finally, add 15g of the mixed solvent (ethylene glycol butyl ether and propylene glycol methyl ether in a volume ratio of 1:1) and stir at low speed for 30 minutes.

[0075] After filtration and encapsulation, a milky white thermosensitive color-changing intelligent temperature-regulating and heat-insulating coating is obtained.

[0076] Example 2:

[0077] Step 1: Preparation of thermosensitive color-changing microcapsules: Weigh 20g of cholesterol caprylate and 10g of cholesterol stearate, add 10g of dibutyl phthalate (DBP), heat to 60℃ and stir evenly to obtain the oil phase;

[0078] Prepare a solution by dissolving 3g of polyvinyl alcohol (PVA) in 100mL of deionized water in an aqueous phase and stirring.

[0079] The oil phase and the water phase were emulsified at 12,000 rpm for 5 minutes in a shear emulsification apparatus.

[0080] Add 10 mL of methyl methacrylate (MMA) and 0.5 g of benzoyl peroxide to the system, and polymerize at 50 °C for 8 hours;

[0081] Centrifugation, washing three times, and vacuum drying yielded thermosensitive microcapsules with an average particle size of approximately 2 μm and a color change temperature range of 30-38℃.

[0082] Step 2: Preparation of phase change energy storage microcapsules: Weigh 80g of hexadecyl alcohol and heat it to 70℃ until completely melted;

[0083] Separately, 20g of tetraethyl orthosilicate, 2g of KH-560, and 1mL of ammonia were added to 200mL of ethanol and stirred to prepare a coated precursor sol.

[0084] The sol was slowly added dropwise to cetyl alcohol while being stirred at high speed and sonicated for 10 minutes.

[0085] The reaction was carried out at 40℃ for 6 hours.

[0086] After centrifugation, washing and drying yielded white phase change energy storage microcapsules with a particle size of approximately 400 nm.

[0087] Step 3: Preparation of VO2(W)-TiO2 composite particles

[0088] Dissolve 80g of ammonium vanadate and 12g of sodium tungstate in 300mL of deionized water;

[0089] Add 10g of citric acid complexing agent and adjust the pH to 4.5;

[0090] The product was subjected to hydrothermal reaction at 180℃ for 12 hours, and after cooling, it was blended with nano-TiO2 (50nm) at a mass ratio of 1:1.

[0091] After ball milling for 30 minutes, calcined at 550℃ in an argon atmosphere for 2 hours;

[0092] After cooling and grinding, VO2(W)-TiO2 composite particles with an average particle size of about 40 nm were obtained.

[0093] Step 4: Preparation of smart coating: Accurate weighing: 60g acrylic modified polyurethane resin, 10g temperature-sensitive microcapsules, 6g phase change energy storage microcapsules, 10g VO2 thermal control particles;

[0094] VO2 thermal control particles and phase change energy storage microcapsules were added to resin and ultrasonically dispersed for 15 minutes.

[0095] Add the temperature-sensitive microcapsules and continue stirring for 15 minutes;

[0096] Add 0.8g of light stabilizer HALS-770, 2g of sodium dodecylbenzenesulfonate, and 0.5g of organobentonite;

[0097] Add 16g of a mixture of ethylene glycol butyl ether and propylene glycol methyl ether solvents and stir for 30 minutes;

[0098] After filtration and sealing, a smart temperature-regulating and heat-insulating coating for high-reflectivity energy saving on roofs is obtained.

[0099] Example 3:

[0100] Step 1: The preparation of thermosensitive color-changing microcapsules is the same as in Example 1.

[0101] Step 2: Preparation of phase change energy storage microcapsules: Weigh 60g of decanol and 20g of dodecanol, mix and heat to 65℃ to melt;

[0102] Add 18g of tetraethyl orthosilicate, 1.8g of KH-560, and 1mL of ammonia to 200mL of ethanol, and stir until well mixed;

[0103] Emulsification and mixing were carried out at a stirring speed of 10,000 rpm, a reaction temperature of 40°C, and a reaction time of 6 hours.

[0104] After cooling, centrifugation, washing, and drying, phase change capsules with a particle size of approximately 300 nm and a melting point of 30-40 °C were obtained.

[0105] Step 3: Preparation of VO2(W)-TiO2 composite particles: Same as in Example 1, but the tungsten doping ratio is reduced to 5% to enhance light transmittance;

[0106] The particle size is controlled at 30-40nm.

[0107] Step 4: Prepare the coating: Accurately weigh: 75g polyurethane resin, 8g thermosensitive microcapsules, 10g phase change capsules, and 5g VO2 particles;

[0108] Add thermally controlled particles and phase change energy storage microcapsules sequentially, and disperse ultrasonically for 10 minutes;

[0109] Add the temperature-sensitive microcapsules and continue stirring for 15 minutes;

[0110] Add 0.6g of HALS-770, 1.2g of dispersant, and 0.3g of rheology modifier;

[0111] Add 12g of mixed solvent, stir for 30 minutes, filter and encapsulate to obtain a smart temperature-controlled heat insulation coating for photovoltaic backsheets.

[0112] Example 4:

[0113] Step 1: Preparation of microcapsules (small particle size version): The emulsification speed of the thermosensitive color-changing microcapsules was increased to 16,000 rpm, and the amount of stabilizer PVA was increased to 4g;

[0114] The phase change capsules use tetradecanol, and the microcapsule particle size is controlled within 200nm.

[0115] The coating was performed using the same tetraethyl orthosilicate + KH560 system, with a polymerization temperature of 40℃ and a reaction time of 6 hours.

[0116] Step 2: Preparation of VO2 thermal control particles: VO2 particles are coated with a SiO2 layer to improve flexibility, transparency and water resistance;

[0117] Coating method: Immerse VO2 powder in TEOS alcohol solution, add ammonia water dropwise and react for 4 hours, then dry to obtain the coating.

[0118] Step 3: Preparation of coating: Accurately weigh: 65g flexible polyurethane resin, 10g temperature-sensitive microcapsules, 8g phase change energy storage microcapsules, 4g VO2-SiO2 composite particles, and 2g epoxidized soybean oil as a flexible plasticizer.

[0119] Disperse the mixture ultrasonically for 15 minutes, then add each component in sequence and stir until homogeneous.

[0120] Add 3g of additive and 13g of mixed solvent, and stir until the viscosity is stable;

[0121] Filtering and filling yields a transparent, flexible, and temperature-controlled color-changing coating.

[0122] Example 5:

[0123] Step 1: Preparation of wide-temperature-range color-changing microcapsules: 15g of cholesterol caprylate, 10g of myristate, and 5g of stearate are mixed and heated to 70℃ to form an oil phase;

[0124] Other operations are the same as in Example 1, ultimately forming a ternary cholesteric microcapsule with a color-changing window of 20-45°C.

[0125] Step 2: Preparation of high-melting-point phase change energy storage microcapsules: 80g of n-octadecyl alcohol with a melting point of 61℃ was selected;

[0126] The same silica sol coating system as described above is used;

[0127] The particle size is controlled between 500nm and 800nm.

[0128] Step 3: Preparation of fluorosilicone-coated VO2 thermal control particles: The preparation of VO2(W)-TiO2 composite particles is the same as in Example 1;

[0129] Coating process: It is mixed with polyfluorosiloxane prepolymer and heat-cured at 180°C to form a highly weather-resistant and moisture-proof composite powder.

[0130] Step 4: Coating preparation: 70g resin, 14g thermosensitive microcapsules, 8g phase change energy storage microcapsules, 8g VO2 fluorosilicone composite particles;

[0131] Dispersant, light stabilizer, and rheology modifier total 3g; solvent 13g;

[0132] The dispersion order is the same as before, ultimately forming a military camouflage intelligent temperature-regulating coating with dynamic optical properties and strong temperature-controlled reflection capabilities.

[0133] Performance testing

[0134] The following experimental conditions were used to verify the comparative thermal regulation performance of thermosensitive color-changing intelligent temperature-regulating thermal insulation coatings under complex environments.

[0135] Five aluminum plates with dimensions of 200mm×200mm×3mm were prepared and coated with the coatings of Examples 1-5 respectively, with the dry film thickness maintained at 100μm; two control samples were also set up: one was an uncoated aluminum plate (blank control) and the other was a sample with conventional high-reflectivity white coating.

[0136] Equipped with a sunlight simulation lamp (AM 1.5 standard), illuminance intensity: 1000W / m² 2 High-temperature module: The internal temperature can be adjusted to 60±2℃; Cooling module: It can simulate an environment of 20℃; Cyclic mode: Simulates an environment of "8 hours of direct sunlight during the day + 8 hours of cooling at night" (a total of 24 hours of cycle for 1 day); The ambient humidity is maintained at 60% RH; Experiment duration: 7 complete day and night cycles (a total of 168 hours).

[0137] Experimental steps:

[0138] (I) Surface temperature rise test

[0139] Place the sample vertically on the support, 1.5m away from the simulated light source; turn on the simulated sunlight and record the surface temperature of each sample at 0, 10, 20, 30 and 60 minutes (using a thermal imager and a K-type thermocouple); compare the heating rate and peak temperature of each coating.

[0140] (II) Bottom Greenhouse Model Test

[0141] Each sample is sealed with a 20mm thick foam box, with a temperature probe inside; the "building skin / equipment shell" scenario is simulated, and the temperature change curve inside the box is recorded; the thermal barrier capacity and hysteresis are analyzed.

[0142] (III) Thermal Cyclic Resistance Test

[0143] Perform 7 cycles of alternating hot and cold temperatures (between 60℃ and 20℃) for 24 hours; record the surface discoloration after each cycle (by taking a photo / comparing with a colorimeter), whether the coating peels or cracks; and check whether the heat insulation performance has deteriorated.

[0144] (iv) Infrared reflectivity test

[0145] The reflectance of each sample in the 2500-25000 nm band was scanned using a Fourier transform infrared spectroscopy (FTIR) instrument; the reflectance changes of the VO2 thermal control particles in the working window (700-2500 nm) were compared.

[0146] The experimental results are shown in Table 1.

[0147] Table 1

[0148]

[0149]

[0150] Experiments showed that Examples 2 and 5 exhibited the best overall performance: Example 2's optimized VO2 thermal control efficiency and high reflectivity composition resulted in superior performance in peak temperature control and thermal hysteresis; Example 5 achieved a good balance between all-weather camouflage and thermal regulation capabilities. All examples outperformed traditional high-reflectivity coatings: each coating in this invention outperformed commercially available single high-reflectivity coatings in mitigating surface temperature rise and regulating thermal fluctuations, and also possessed active control capabilities.

[0151] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A temperature-sensitive, color-changing, intelligent temperature-regulating and heat-insulating coating, characterized in that, The components are included by weight as follows: (1) Acrylic modified polyurethane resin, 60-80 parts, used as a coating film-forming matrix; (2) Thermosensitive color-changing microcapsules, 10-15 parts, with cholesteric liquid crystal as the core material and polymethyl methacrylate as the wall material, used for thermosensitive color change and reflectivity adjustment; (3) Phase change energy storage microcapsules, 6-10 parts, with cetyl alcohol as the core material and modified nano-SiO2 as the wall material, are used to absorb and release heat to achieve local temperature control buffering; (4) VO2(W)-TiO2 composite particles, 5-8 parts, with a particle size of 30-80nm; (5) Light stabilizer HALS-770, 0.5-1.0 parts, to improve UV aging resistance; (6) Sodium dodecylbenzenesulfonate dispersant, 1.0-2.0 parts, to improve the stability of nanoparticles and microcapsules in the system; (7) Rheology modifier organic bentonite, 0.3-0.6 parts, to regulate the fluidity and thixotropic properties of coatings and improve their adaptability to construction; (8) Mixed solvent, 10-20 parts, to provide a suitable evaporation rate and balanced polarity.

2. The thermosensitive color-changing intelligent temperature-regulating and heat-insulating coating according to claim 1, characterized in that: The mixed solvent is a mixture of ethylene glycol butyl ether and propylene glycol methyl ether.

3. The thermosensitive color-changing intelligent temperature-regulating and heat-insulating coating according to claim 1, characterized in that: The method for preparing the thermosensitive color-changing microcapsules includes the following steps: Step 1: Mix the cholesteric liquid crystal component with dibutyl phthalate (DBP) plasticizer in a 3:1 ratio to form an oil phase; Step 2: Combine polymethyl methacrylate, polyvinyl alcohol, and water to form an aqueous phase; Step 3: The oil phase and the water phase are mixed and emulsified in a high-speed shear machine at a shear rate of 12,000 rpm for 5 minutes; Step 4: Maintain the temperature at 50℃ for 8 hours for free radical polymerization, then cool, centrifuge, wash with water and dry to obtain microcapsule particles with a particle size of 1-3μm and a coating rate of ≥80%.

4. The thermosensitive color-changing intelligent temperature-regulating and heat-insulating coating according to claim 3, characterized in that: The cholesteric liquid crystal is a mixture of cholesterol caprylate and cholesterol stearate in a mass ratio of 1:1 to 3:1, and it has the following characteristics: Cholesteric liquid crystals are molecular stacked systems with right-handed helical arrangement. Their pitch changes reversibly within a temperature range of 25-40℃, thereby modulating the selective reflection band of visible light. Cholesterol caprylate has a melting point of approximately 36°C, and cholesterol stearate has a melting point of approximately 42°C. When the two are mixed, they form a thermochromic material with a wide response range.

5. The thermosensitive color-changing intelligent temperature-regulating and heat-insulating coating according to claim 1, characterized in that: The preparation method of the phase change energy storage microcapsules is as follows: Step 1: Heat cetyl alcohol to 70°C to melt it; Step 2: Add silane coupling agent KH-560, tetraethyl orthosilicate, and a small amount of ammonia to form a sol in ethanol medium; Step 3: Use interfacial polycondensation + emulsification to coat the cetyl alcohol with a stirring rate of 6000 rpm, a reaction temperature of 40°C, and a reaction time of 6 hours. Step 4: Centrifuge, wash, and dry to obtain spherical microcapsules.

6. The thermosensitive color-changing intelligent temperature-regulating and heat-insulating coating according to claim 1, characterized in that: The preparation method of the VO2(W)-TiO2 composite particles is as follows: Step 1: Dissolve ammonium vanadate and sodium tungstate in deionized water at a molar ratio of 10:1, and add citric acid as a complexing agent; Step 2: Set the hydrothermal reaction temperature to 180℃ and cool after reacting for 12 hours. Step 3: Mix with nano TiO2 at a 1:1 mass ratio and ball mill for 30 minutes using high energy. Step 4: Calcine at 550°C for 2 hours in an argon atmosphere to obtain tungsten-doped VO2 (TiO2) thermal control particles.

7. A thermosensitive color-changing intelligent temperature-regulating and heat-insulating coating according to any one of claims 1-6, characterized in that: The coating preparation method includes the following steps: S1. Thermosensitive color-changing microcapsules, phase change energy storage microcapsules and VO2(W)-TiO2 composite particles are prepared according to the methods of claims 2 to 6 respectively. S2. Add VO2(W)-TiO2 composite particles and phase change energy storage microcapsules to the resin and disperse them in an ultrasonic disperser for 15 minutes. S3. Add the temperature-sensitive microcapsules, light stabilizer, dispersant, and rheology modifier in sequence, and stir for 30 minutes until the system is homogeneous; S4. Add the mixed solvent to dilute to the application viscosity, filter, and then package.

8. The temperature-sensitive color-changing intelligent temperature-regulating and heat-insulating coating according to claim 1 has application value in the following fields: Building exterior wall and roof insulation system, suitable for energy-saving buildings in hot-summer and cold-winter regions; Photovoltaic module backsheets are used to reduce the decrease in electrical efficiency caused by temperature rise. Surfaces of industrial equipment with high thermal management requirements, such as energy storage devices, transformer substations, and vehicle shells.

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