Heat-insulating film with self-adjusting light transmittance and high heat insulation performance and preparation method of heat-insulating film

Abstract

The invention discloses a heat-insulating film with self-adjusting light transmittance and high heat insulation and a preparation method thereof, and relates to the technical field of heat-insulating films. The preparation method comprises the following steps: preparing aerogel slurry from aerogel powder, an auxiliary agent, water and a resin emulsion, preparing a photoresponse gel layer from a polymeric monomer and a photoresponse monomer, preparing a metal photosensitive coating from a metal oxide, a surfactant and a silane coupling agent, coating a substrate with the aerogel slurry, and drying to obtain the thermal insulation film. The light response gel layer continues to be attached to the slurry coating, after drying, the light sensation coating continues to be attached to the light response gel layer, and finally a layer of base material is attached to the upper portion. The heat-insulating film provided by the invention not only has the functions of blocking infrared rays and ultraviolet rays and insulating heat, but also has the function of self-adjusting the light transmittance, the light transmittance can be adjusted according to the external temperature, the light transmittance can be reduced in high-temperature weather, and the high light transmittance can be kept in low-temperature weather.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal insulation films, and in particular to a thermal insulation film with self-regulating light transmittance and high thermal insulation, and a preparation method thereof. Background Art

[0002] Due to the large amount of glass used in vehicles, in the daily use of the car, the infrared, ultraviolet and heat in the sunlight will be transmitted into the car under the sun's irradiation; ultraviolet rays can cause skin injuries to people in the car, accelerate the aging and fading of items in the car; infrared rays and heat can cause the temperature in the car to rise, affecting the riding comfort in the car, increasing the frequency and intensity of using air conditioners, consuming more fuel and electricity, and increasing energy consumption; at the same time, the sunlight is strong in summer, and the light can cause dazzle to drivers, increasing driving safety hazards. Automotive glass thermal insulation film is a film material applied to car windows to resist infrared and ultraviolet rays in the sun and reduce the temperature in the car. Especially for the roof sunroof or panoramic sunroof, it is required to maintain a good light transmittance under normal temperature conditions so that the scenery outside the sunroof can be observed while receiving a certain amount of light; and under higher temperature conditions, it is necessary to have a lower light transmittance to avoid strong direct light causing excessive temperature in the car or sunburn. At the same time, for this type of sunroof, it is also necessary to minimize the transmission of infrared, ultraviolet and heat into the car.

[0003] For example, the invention patent with publication number CN118638455A provides a composite solar film with high efficiency in sun protection and heat insulation. Polyvinyl alcohol is used to improve the dispersion of ultraviolet absorbers and the absorption efficiency of ultraviolet rays by the solar film. Polyurethane with added indium tin oxide is used to improve the ability of the solar film to reflect near-infrared rays and reduce heat energy penetration. Polyvinyl pyrrolidone is used to further improve the mechanical properties of the solar film. However, the blocking rate of the solar film for visible light is less than 5%, which cannot effectively reduce the glare problem caused by strong light to the driver, and is difficult to be applied to roof sunroofs. Summary of the invention

[0004] In order to solve at least one of the above problems, the present invention proposes a heat-insulating film with self-regulating light transmittance and high heat insulation and a preparation method thereof.

[0005] The technical solution of the present invention is: a method for preparing a heat-insulating film with self-regulating light transmittance and high heat insulation, which comprises the following steps in parts by mass: Preparation of aerogel slurry: based on a total of 100 parts, take 10 to 40 parts of hydrophobic aerogel powder, 10 to 30 parts of a first film-forming aid, and the balance is water, and stir evenly to obtain a mixed slurry; take 30 to 40 parts of the mixed slurry, add 20 to 55 parts of a resin emulsion and 0.5 to 30 parts of a second film-forming aid, and then grind it with a ball mill; the first film-forming aid contains 40 to 60 parts of a wetting agent, 20 to 30 parts of a dispersant, and 10 to 30 parts of a defoaming agent; the second film-forming aid contains 10 to 20 parts of a defoaming agent, 5 to 10 parts of a thickener, and 70 to 85 parts of a leveling agent.

[0006] Preparation of temperature-responsive gel layer: based on 100 parts in total, take 1-4 parts of polymerization monomer, 1-3 parts of temperature-responsive monomer, 0.09-0.25 parts of initiator, and the rest of water, and after complete dissolution, spread the solution and perform free radical polymerization to obtain a polymer gel layer; Preparation of the photosensitive coating: based on 100 parts in total, take 5-15 parts of antimony tin oxide, 1-5 parts of lanthanum hexaboride, 1-5 parts of tungsten oxide, 1-3 parts of nonionic surfactant, 1-8 parts of silane coupling agent, and the rest of water, mix them evenly, and then grind them with a ball mill to obtain the obtained product; Preparation of thermal insulation film: take aerogel slurry and apply it on the lower substrate and dry it to form a base, then apply a layer of adhesive on the base, bond the temperature responsive gel layer to the base, apply another layer of adhesive, bond the photosensitive coating, and then apply another layer of adhesive to bond the upper substrate.

[0007] In one embodiment of the present invention, the hydrophobic aerogel powder is one of hydrophobic silica aerogel powder, alumina aerogel powder, polyimide aerogel powder and carbon aerogel powder, and its density is 30-100 kg / m 3 , particle size is 10~100μm.

[0008] One embodiment of the present invention is that the defoamer is at least one of an acrylic defoamer, a silicone defoamer, a polyolefin defoamer, and a fluorine-containing defoamer; the thickener is one of hydroxyethyl cellulose, carboxymethyl cellulose, and hydroxypropyl methyl cellulose; the leveling agent is one of an silicone leveling agent, an acrylate leveling agent, and a fluorine-modified leveling agent; the wetting agent is one of a cationic surfactant, an anionic surfactant, or a nonionic surfactant; and the dispersant is one of polyvinyl alcohol or sodium polyacrylate.

[0009] An embodiment of the present invention is that during the preparation of the aerogel slurry, the stirring speed of the mixed slurry is 800-1000 r / min.

[0010] An embodiment of the present invention is that the resin emulsion is one of an aqueous polyacrylic resin and an aqueous polyurethane emulsion.

[0011] One embodiment of the present invention is that the polymerization monomer is one or both of acrylamide and acrylic acid; the temperature responsive monomer is one or both of N-vinyl caprolactam and N-isopropyl acrylamide; the initiator is a photoinitiator, and the polymerization condition of the free radical polymerization is ultraviolet irradiation.

[0012] One embodiment of the present invention is that the nonionic surfactant is one or more of Span-80, Span-60, Tween-80, OP-10, etc.; the silane coupling agent is one of methyltrimethoxysilane, methyltriethoxysilane, octyltrimethoxysilane, octadecyltrimethoxysilane, vinyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane.

[0013] An embodiment of the present invention is that the thickness of the aerogel slurry coating is 50-500 μm, the thickness of the polymer gel layer is 10-100 μm, the thickness of the photosensitive coating is 10-100 μm, and the thickness of the substrate is 10-100 μm.

[0014] An embodiment of the present invention is that the upper substrate and the lower substrate are independently one of a PET substrate, a polycarbonate substrate, and a polypropylene substrate; and the adhesive is a water-based acrylic resin.

[0015] Another object of the present invention is to disclose a heat-insulating film with self-regulating light transmittance and high heat insulation, which is prepared by any of the above methods.

[0016] Beneficial effects: The thermal insulation film provided by the present invention not only has the function of blocking infrared rays, ultraviolet rays and heat insulation, but also has the function of self-regulating light transmittance. It can adaptively adjust the light transmittance according to the external temperature, reduce the light transmittance in high temperature weather, maintain a high light transmittance in low temperature weather, and reduce driving safety hazards. DETAILED DESCRIPTION

[0017] The specific implementation modes of the present invention will be described clearly and completely below with reference to examples. Obviously, the examples described are only some embodiments of the present invention, rather than all embodiments.

[0018] In this embodiment, unless otherwise specified, all materials used are conventional commercial products in the art.

[0019] Example 1: Preparation of aerogel slurry: Take 20 parts of hydrophobic silica aerogel powder (density 50 kg / m 3, particle size 10-50μm), 50 parts of deionized water, 10 parts of wetting agent cationic surfactant, 4 parts of polyvinyl alcohol dispersant, 6 parts of acrylic defoaming agent, stirred at a speed of 900 r / min for 30 min to obtain a mixed slurry; 40 parts of the mixed slurry were added with 45 parts of aqueous acrylic resin emulsion, 1.5 parts of carboxymethyl cellulose, 2.25 parts of acrylic defoaming agent, and 11.25 parts of acrylic ester leveling agent, and stirred at 250 r / min for 12 hours in a ball mill to obtain an aerogel insulation slurry.

[0020] Preparation of polymer gel layer: 3 parts of acrylamide, 1 part of N-isopropylacrylamide and 0.1 parts of photoinitiator (2,2-diethoxyacetophenone) were dissolved in 95.9 parts of deionized water. The monomer solution was loaded into a glass mold of the required thickness (50 μm), and polymerized in a UV lamp reactor under nitrogen atmosphere for 4 hours to obtain a polymer gel layer with sunlight regulation function.

[0021] Preparation of the photosensitive coating: 10 parts of antimony tin oxide, 3 parts of lanthanum hexaboride, 2 parts of tungsten oxide, 2 parts of nonionic surfactant, 6 parts of silane coupling agent MTES, and 77 parts of water were mixed and stirred in a ball mill at 250 r / min for 12 hours to obtain an aerogel insulation slurry.

[0022] Preparation of thermal insulation film: Apply aerogel thermal insulation slurry on the lower substrate PET as a base with a thickness of 50 μm and dry at 80°C for 1 hour; then apply adhesive water-based acrylic resin on this layer, followed by a polymer gel layer with a thickness of 80 μm and dry at 80°C for 2 hours; then apply adhesive water-based acrylic resin on this layer, followed by a photosensitive coating with a thickness of 50 μm and dry at 80°C for 2 hours; then apply adhesive water-based acrylic resin on this layer and bond it to the upper substrate PET.

[0023] Example 2: Preparation of aerogel slurry: Take 25 parts of hydrophobic silica aerogel powder (density 50 kg / m 3 , particle size 10-50μm), 45 parts of deionized water, 15 parts of wetting agent cationic surfactant, 8 parts of polyvinyl alcohol dispersant, 7 parts of acrylic defoaming agent, and stirred at a speed of 900 r / min for 30 min to obtain a mixed slurry; 40 parts of the mixed slurry were added with 45 parts of aqueous polyurethane emulsion, 2 parts of carboxymethyl cellulose, 1 part of acrylic defoaming agent, and 12 parts of acrylic ester leveling agent, and stirred at 250 r / min for 12 hours in a ball mill to obtain an aerogel insulation slurry.

[0024] Preparation of polymer gel layer: 2 parts of acrylamide, 1 part of acrylic acid, 1 part of N-isopropylacrylamide, 1 part of N-vinylcaprolactam and 0.02 parts of photoinitiator (2,2-diethoxyacetophenone) were dissolved in 94.98 parts of deionized water. The monomer solution was loaded into a glass mold of the required thickness (50 μm), and polymerized in a UV lamp reactor under nitrogen atmosphere for 4 hours to obtain a polymer gel layer with sunlight regulation function.

[0025] Preparation of photosensitive coating: 12 parts of antimony tin oxide, 4 parts of lanthanum hexaboride, 1 part of tungsten oxide, 3 parts of non-ionic surfactant, 7 parts of silane coupling agent OTMS, and 73 parts of water were mixed and stirred in a ball mill at 250 r / min for 12 hours to obtain aerogel insulation slurry.

[0026] Preparation of thermal insulation film: Apply aerogel thermal insulation slurry on the lower substrate PET as a base with a thickness of 60 μm and dry at 80°C for 1 hour; then apply adhesive water-based acrylic resin on this layer, followed by a polymer gel layer with a thickness of 50 μm and dry at 80°C for 2 hours; then apply adhesive water-based acrylic resin on this layer, followed by a photosensitive coating layer with a thickness of 100 μm and dry at 80°C for 2 hours; then apply adhesive water-based acrylic resin on this layer and bond it to the upper substrate PET.

[0027] Example 3: Preparation of aerogel slurry: Take 30 parts of alumina aerogel powder (density 70 kg / m 3 , particle size 20-50μm), 60 parts of deionized water, 5 parts of wetting agent cationic surfactant, 3 parts of polyvinyl alcohol dispersant, 2 parts of acrylic defoaming agent, and stirred at a speed of 900 r / min for 30 min to obtain a mixed slurry; 30 parts of the mixed slurry were added with 55 parts of aqueous polyurethane emulsion, 3 parts of hydroxyethyl cellulose, 1.5 parts of silicone defoaming agent, and 10.5 parts of silicone leveling agent, and stirred at 250r / min for 12h in a ball mill to obtain an aerogel insulation slurry.

[0028] Preparation of polymer gel layer: 5 parts of acrylic acid, 1 part of N-vinyl caprolactam and 0.15 parts of photoinitiator (2,2-diethoxyacetophenone) were dissolved in 94.85 parts of deionized water. The monomer solution was loaded into a glass mold of the required thickness (50 μm), and polymerized in a UV lamp reactor under nitrogen atmosphere for 4 hours to obtain a polymer gel layer with sunlight regulation function.

[0029] Preparation of the photosensitive coating: 5 parts of antimony tin oxide, 5 parts of lanthanum hexaboride, 5 parts of tungsten oxide, 1 part of a cationic surfactant, 1 part of a silane coupling agent ODTMS, and 83 parts of water were mixed and stirred in a ball mill at 250 r / min for 12 hours to obtain an aerogel insulation slurry.

[0030] Preparation of thermal insulation film: Apply aerogel thermal insulation slurry on the lower substrate PET as a base with a thickness of 100 μm and dry at 80°C for 1 hour; then apply adhesive water-based acrylic resin on this layer, followed by a polymer gel layer with a thickness of 50 μm and dry at 80°C for 2 hours; then apply adhesive water-based acrylic resin on this layer, followed by a photosensitive coating with a thickness of 100 μm and dry at 80°C for 2 hours; then apply adhesive water-based acrylic resin on this layer and bond it to the upper substrate PET.

[0031] Example 4: Preparation of aerogel slurry: Take 10 parts of polyimide aerogel powder (density 100 kg / m 3 , particle size 50-70μm), 76 parts of deionized water, 7 parts of wetting agent anionic surfactant, 3 parts of sodium polyacrylate dispersant, 4 parts of polyolefin defoaming agent, and stirring at a speed of 900 r / min for 30 min to obtain a mixed slurry; take 30 parts of the mixed slurry, add 40 parts of aqueous polyurethane emulsion, 3 parts of carboxymethyl cellulose, 6 parts of acrylic defoaming agent, and 21 parts of acrylic ester leveling agent, use a ball mill to stir at 250 r / min for 12h to obtain an aerogel insulation slurry.

[0032] Preparation of polymer gel layer: 1 part acrylamide, 2 parts N-isopropyl acrylamide, 1 part N-vinyl caprolactam and 0.25 parts photoinitiator (2,2-diethoxyacetophenone) were dissolved in 95.75 parts deionized water. The monomer solution was loaded into a glass mold of the required thickness (50 μm), and polymerized in a UV lamp reactor under nitrogen atmosphere for 4 hours to obtain a polymer gel layer with sunlight regulation function.

[0033] Preparation of photosensitive coating: 15 parts of antimony tin oxide, 2 parts of lanthanum hexaboride, 3 parts of tungsten oxide, 2 parts of non-ionic surfactant, 3 parts of silane coupling agent VTMS, and 75 parts of water were mixed and stirred in a ball mill at 250 r / min for 12 hours to obtain aerogel insulation slurry.

[0034] Preparation of thermal insulation film: Apply aerogel thermal insulation slurry on the lower substrate PET as a base, with a thickness of 500μm, and dry at 80℃ for 1h; then apply adhesive water-based acrylic resin on this layer, and then apply a layer of polymer gel with a thickness of 10μm, and dry at 80℃ for 2h; then apply adhesive water-based acrylic resin on this layer, and then apply a layer of photosensitive coating with a thickness of 10μm, and dry at 80℃ for 2h; then apply adhesive water-based acrylic resin on this layer, and bond it to the upper substrate PET.

[0035] Example 5: Preparation of aerogel slurry: Take 10 parts of carbon aerogel powder (density 30 kg / m 3, particle size 60-100μm), 60 parts of deionized water, 13 parts of wetting agent non-ionic surfactant, 9 parts of polyvinyl alcohol, and 8 parts of acrylic defoaming agent, and stirred at a speed of 900 r / min for 30 min to obtain a mixed slurry; 40 parts of the mixed slurry were added with 45 parts of aqueous polyurethane emulsion, 2 parts of carboxymethyl cellulose, 1 part of acrylic defoaming agent, and 12 parts of acrylic ester leveling agent, and stirred at 250 r / min for 12 hours in a ball mill to obtain an aerogel insulation slurry.

[0036] Preparation of polymer gel layer: 4 parts of acrylamide, 3 parts of N-vinyl caprolactam and 0.2 parts of photoinitiator (2,2-diethoxyacetophenone) were dissolved in 93.8 parts of deionized water. The monomer solution was loaded into a glass mold of the required thickness (50 μm), and polymerized in a UV lamp reactor under nitrogen atmosphere for 4 hours to obtain a polymer gel layer with sunlight regulation function.

[0037] Preparation of the photosensitive coating: 15 parts of antimony tin oxide, 1 part of lanthanum hexaboride, 1 part of tungsten oxide, 2 parts of cationic surfactant, 5 parts of silane coupling agent KH570, and 76 parts of water were mixed and stirred in a ball mill at 250 r / min for 12 hours to obtain an aerogel insulation slurry.

[0038] Preparation of thermal insulation film: Apply aerogel thermal insulation slurry on the lower substrate PET as a base with a thickness of 500μm and dry at 80℃ for 1h; then apply adhesive water-based acrylic resin on this layer, followed by a polymer gel layer with a thickness of 100μm and dry at 80℃ for 2h; then apply adhesive water-based acrylic resin on this layer, followed by a photosensitive coating layer with a thickness of 50μm and dry at 80℃ for 2h; then apply adhesive water-based acrylic resin on this layer and bond it to the upper substrate PET.

[0039] Example 6: Preparation of aerogel slurry: Take 45 parts of hydrophobic alumina aerogel powder (density 70 kg / m 3 , particle size 20-50μm), 35 parts of deionized water, 10 parts of wetting agent cationic surfactant, 4 parts of sodium polyacrylate, 6 parts of fluorine-containing defoaming agent, and stirring at a speed of 900 r / min for 30 min to obtain a mixed slurry; take 30 parts of the mixed slurry, add 20 parts of aqueous polyacrylic acid emulsion, 5 parts of hydroxypropyl methylcellulose, 10 parts of fluorine-containing defoaming agent, 35 parts of fluorine-modified leveling agent, use a ball mill to stir at 250 r / min for 12h to obtain an aerogel insulation slurry.

[0040] Preparation of polymer gel layer: 2 parts of acrylamide, 2 parts of acrylic acid, 1 part of N-vinyl caprolactam and 0.15 parts of photoinitiator (2,2-diethoxyacetophenone) were dissolved in 94.85 parts of deionized water. The monomer solution was loaded into a glass mold of the required thickness (50 μm), and polymerized in a UV lamp reactor under nitrogen atmosphere for 4 hours to obtain a polymer gel layer with sunlight regulation function.

[0041] Preparation of photosensitive coating: 8 parts of antimony tin oxide, 2 parts of lanthanum hexaboride, 5 parts of tungsten oxide, 2 parts of non-ionic surfactant, 8 parts of silane coupling agent MTMS, and 75 parts of water were mixed and stirred in a ball mill at 250 r / min for 12 hours to obtain aerogel insulation slurry.

[0042] Preparation of thermal insulation film: Apply aerogel thermal insulation slurry on the lower substrate PET as a base, with a thickness of 200μm, and dry at 80℃ for 1h; then apply adhesive water-based acrylic resin on this layer, and then apply a layer of polymer gel with a thickness of 70μm, and dry at 80℃ for 2h; then apply adhesive water-based acrylic resin on this layer, and then apply a layer of photosensitive coating with a thickness of 80μm, and dry at 80℃ for 2h; then apply adhesive water-based acrylic resin on this layer and bond it to the upper substrate PET.

[0043] Example 7: Preparation of aerogel slurry: Take 25 parts of hydrophobic silica aerogel powder (density 50 kg / m 3 , particle size 10-50μm), 50 parts of deionized water, 13 parts of wetting agent cationic surfactant, 7 parts of polyvinyl alcohol, and 5 parts of silicone defoaming agent, and stirred at a speed of 900 r / min for 30 min to obtain a mixed slurry; 35 parts of the mixed slurry were added with 45 parts of water-based acrylic resin, 3 parts of carboxymethyl cellulose, 2 parts of acrylic defoaming agent, and 15 parts of silicone leveling agent, and stirred at 250r / min for 12h in a ball mill to obtain an aerogel insulation slurry.

[0044] Preparation of polymer gel layer: 2 parts of acrylamide, 1 part of acrylic acid, 1 part of N-isopropylacrylamide, 1 part of N-vinylcaprolactam and 0.15 parts of photoinitiator (2,2-diethoxyacetophenone) were dissolved in 94.85 parts of deionized water. The monomer solution was loaded into a glass mold of the required thickness (50 μm), and polymerized in a UV lamp reactor under nitrogen atmosphere for 4 hours to obtain a polymer gel layer with sunlight regulation function.

[0045] Preparation of the photosensitive coating: 12 parts of antimony tin oxide, 3 parts of lanthanum hexaboride, 3 parts of tungsten oxide, 2 parts of cationic surfactant, 5 parts of silane coupling agent KH570, and 75 parts of water were mixed and stirred in a ball mill at 250 r / min for 12 hours to obtain an aerogel insulation slurry.

[0046] Preparation of thermal insulation film: Apply aerogel thermal insulation slurry on the lower substrate PET substrate as a base, with a thickness of 200μm, and dry at 80℃ for 1h; then apply adhesive water-based acrylic resin on this layer, followed by a polymer gel layer with a thickness of 75μm, and dry at 80℃ for 2h; then apply adhesive water-based acrylic resin on this layer, followed by a photosensitive coating layer with a thickness of 85μm, and dry at 80℃ for 2h; then apply adhesive water-based acrylic resin on this layer, and bond it to the upper substrate PET.

[0047] In order to further illustrate the performance of the thermal insulation film prepared in the embodiment of the present invention, it is tested as follows.

[0048] The thermal insulation rate is measured by an automobile film thermal insulation rate tester.

[0049] Visible light transmittance, infrared light rejection and ultraviolet light rejection are obtained by testing with LS103 optical transmittance measuring instrument.

[0050] The final results are shown in Table 1.

[0051] Table 1 Test results

[0052] As can be seen from Table 1, the thermal insulation film prepared in the embodiment of the present invention has a certain thermal insulation rate, a high visible light transmittance, and a very high infrared and ultraviolet light blocking rate. At the same time, it also has a good temperature self-adaptation function, so that the thermal insulation film has a good light transmittance in cloudy days and other low temperature weather, reducing driving hazards; at the same time, it can reduce the light transmittance in high temperature weather and reduce the glare caused by strong light.

[0053] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a heat-insulating film with self-regulating light transmittance and high heat insulation, characterized in that: The method comprises the following steps, in parts by mass: Preparation of aerogel slurry: based on 100 parts in total, take 10-40 parts of hydrophobic aerogel powder, 10-30 parts of the first film-forming aid, and the balance is water, and stir evenly to obtain a mixed slurry; take 30-40 parts of the mixed slurry, add 20-55 parts of resin emulsion and 0.5-30 parts of the second film-forming aid, and then grind it with a ball mill; the first film-forming aid contains 40-60 parts of a wetting agent, 20-30 parts of a dispersant, and 10-30 parts of a defoaming agent; the second film-forming aid contains 10-20 parts of a defoaming agent, 5-10 parts of a thickener, and 70-85 parts of a leveling agent; Preparation of temperature-responsive gel layer: based on 100 parts in total, take 1-4 parts of polymerization monomer, 1-3 parts of temperature-responsive monomer, 0.09-0.25 parts of initiator, and the rest of water, and after complete dissolution, spread the solution and perform free radical polymerization to obtain a polymer gel layer; Preparation of the photosensitive coating: based on 100 parts in total, take 5-15 parts of antimony tin oxide, 1-5 parts of lanthanum hexaboride, 1-5 parts of tungsten oxide, 1-3 parts of nonionic surfactant, 1-8 parts of silane coupling agent, and the rest of water, mix them evenly, and then grind them with a ball mill to obtain the obtained product; Preparation of thermal insulation film: take aerogel slurry and apply it on the lower substrate and dry it to form a base, then apply a layer of adhesive on the base, bond the temperature responsive gel layer to the base, apply another layer of adhesive, bond the photosensitive coating, and then apply another layer of adhesive to bond the upper substrate.

2. The method according to claim 1, characterized in that The hydrophobic aerogel powder is one of hydrophobic silica aerogel powder, alumina aerogel powder, polyimide aerogel powder and carbon aerogel powder, and its density is 30-100 kg / m 3 , particle size is 10~100μm.

3. The method according to claim 1, characterized in that The defoamer is at least one of acrylic defoamer, silicone defoamer, polyolefin defoamer, and fluorine-containing defoamer; the thickener is one of hydroxyethyl cellulose, carboxymethyl cellulose, and hydroxypropyl methyl cellulose; the leveling agent is one of silicone leveling agent, acrylate leveling agent, and fluorine-modified leveling agent; the wetting agent is one of cationic surfactant, anionic surfactant, or nonionic surfactant; and the dispersant is one of polyvinyl alcohol or sodium polyacrylate.

4. The method according to claim 1, characterized in that: During the preparation of the aerogel slurry, the stirring speed of the mixed slurry is 800~1000r / min.

5. The method according to claim 1, characterized in that The resin emulsion is one of water-based polyacrylic resin and water-based polyurethane emulsion.

6. The method according to claim 1, characterized in that The polymerization monomer is one or both of acrylamide and acrylic acid; the temperature response monomer is one or both of N-vinyl caprolactam and N-isopropyl acrylamide; the initiator is a photoinitiator, and the polymerization condition of the free radical polymerization is ultraviolet irradiation.

7. The method according to claim 1, characterized in that The nonionic surfactant is one or more of Span-80, Span-60, Tween-80, OP-10, etc.; the silane coupling agent is one of methyltrimethoxysilane, methyltriethoxysilane, octyltrimethoxysilane, octadecyltrimethoxysilane, vinyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane.

8. The method according to claim 1, characterized in that The thickness of the aerogel slurry coating is 50-500 μm, the thickness of the polymer gel layer is 10-100 μm, the thickness of the photosensitive coating is 10-100 μm, and the thickness of the substrate is 10-100 μm.

9. The method according to claim 1, characterized in that: The upper substrate and the lower substrate are independently one of a PET substrate, a polycarbonate substrate and a polypropylene substrate; and the adhesive is a water-based acrylic resin.

10. A heat-insulating film with self-regulating light transmittance and high heat insulation, prepared by the method according to any one of claims 1 to 9.

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