Low emissivity insulating glass with functional coating and method for making same

Abstract

The application discloses a kind of low radiation heat insulation glass containing functional coating and preparation method thereof, it is related to paint technology field.The low radiation heat insulation glass containing functional coating prepared by the application includes glass base material and functional coating coated on its surface, and functional coating is formed by the curing of coating composition including organosilicon modified acrylic resin, core-shell structure antimony-doped tin oxide@silicon dioxide composite nanoparticles, cesium-doped tungsten oxide@polymer pre-dispersion and silane-terminated hyperbranched polyester leveling agent.The coating of the application realizes wide spectrum near-infrared barrier while maintaining high visible light transmittance, has low radiation function, strong adhesion, excellent UV aging resistance and moisture heat cycle resistance, and is suitable for automobile glass heat insulation energy-saving field.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a low-emissivity heat-insulating glass containing a functional coating and its preparation method. Background Technology

[0002] With the continuous growth of car ownership and the increasing demands for energy efficiency from new energy vehicles, the heat insulation and energy-saving performance of automotive glass has become a focus of industry attention. Automotive glass is one of the main channels for heat exchange within the vehicle, especially during the summer when the car is parked and exposed to direct sunlight. Solar radiation enters the vehicle through the glass, causing a sharp rise in interior temperature and increasing the energy consumption of the air conditioning system. Simultaneously, heat radiation from high-temperature objects outside the vehicle also transfers heat into the interior through the glass. Therefore, developing automotive glass coatings that combine high visible light transmittance, high infrared blocking rate, and low radiation is of significant practical importance.

[0003] However, the following technical challenges still exist in the existing technology for functional coatings used in automotive glass.

[0004] First, it is difficult to achieve both high transparency and high infrared blocking performance simultaneously. Existing heat-insulating coatings often add large amounts of micron-sized functional fillers, such as hollow glass microspheres and large-particle titanium dioxide, to achieve infrared blocking performance. This leads to increased coating haze and a sharp decrease in visible light transmittance, failing to meet the optical quality (visible light transmittance, etc.) requirements of automotive windshields. Some technologies employ multi-layer composite coating designs, but the significant differences in the coefficients of thermal expansion between the layers mean that under conditions of drastic outdoor temperature changes, interlayer thermal stress accumulates continuously, easily leading to coating cracking or interlayer delamination, severely affecting durability.

[0005] Secondly, in existing low-emissivity coatings, the refractive index difference between transparent conductive oxide nanoparticles and the resin matrix is ​​large. When the particles are added in high amounts, they are prone to severe Rayleigh scattering, which causes the coating haze to increase. In addition, some transparent conductive oxide particles have strong photocatalytic activity. When exposed to ultraviolet light for a long time, they will catalyze the photo-oxidative degradation of the resin matrix, resulting in yellowing and chalking of the coating, and loss of heat insulation and low-emissivity functions.

[0006] Third, existing radiation-cooling coatings aim for high solar reflectivity and high atmospheric window emissivity, making them suitable for non-transparent applications such as building exteriors. However, automotive glass requires the transmission of visible light, the blocking of near-infrared light, and differentiated spectral selectivity with low emissivity in the far-infrared band—these are opposing requirements. Applying architectural radiation-cooling coatings directly to automotive glass would result in excessively low visible light transmittance, compromising driving safety.

[0007] Fourth, existing nano-functional fillers suffer from difficulties in dispersion and agglomeration during coating preparation. In particular, when blending various nanoparticles with different densities and morphologies, the lack of effective interface control methods makes it difficult to achieve uniform and stable dispersion of nanoparticles in the resin matrix, resulting in poor batch-to-batch consistency of coating performance.

[0008] Fifth, during the curing process, existing functional coatings for automotive glass rely primarily on physical adsorption or a small amount of hydrogen bonding between the coating and the glass substrate, lacking a stable chemical bonding interface. Under harsh operating environments such as long-term rain erosion, ultraviolet radiation, and alternating high and low temperatures, the coating adhesion and weather resistance are difficult to guarantee, and failure phenomena such as blistering and peeling are prone to occur. Summary of the Invention

[0009] The purpose of this invention is to provide a low-emissivity heat-insulating glass containing a functional coating and a method for preparing the same, so as to solve the problems mentioned in the background art.

[0010] In a first aspect, the present invention provides a low-emissivity heat-insulating glass containing a functional coating, the low-emissivity heat-insulating glass comprising a glass substrate and a functional coating coated on the surface of the glass substrate, the functional coating being formed by applying and curing a functional coating material. Functional coatings, by weight, include the following raw materials: 80-120 parts of silicone-modified acrylic resin; 20-35 parts of core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterials; 8-14 parts of cesium-doped tungsten oxide@polymer predispersion; 0.5-3 parts of silane-terminated hyperbranched polyester leveling agent; 0.1-0.5 parts of silicone defoamer; 150-250 parts of mixed solvent; As a preferred embodiment of the present invention, the organosilicon-modified acrylic resin has a solid content of 50±2%, a hydroxyl value of 60-80 mgKOH / g, and a silicon content of 5-10%.

[0011] As a preferred embodiment of the present invention, the preparation method of the core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterial is as follows: A1. Add the antimony-doped tin oxide nanopowder to an ethanol solution composed of anhydrous ethanol and deionized water, ultrasonically disperse for 20-40 min, and adjust the pH to 4-5 with glacial acetic acid to obtain the antimony-doped tin oxide dispersion. The mass ratio of antimony-doped tin oxide nanopowder, anhydrous ethanol, and deionized water is 1:9:1. A2. Under stirring conditions at 25℃, tetraethyl orthosilicate is added dropwise to the antimony-doped tin oxide dispersion prepared in step A1 for 1.5-2 hours. After the addition is complete, 25% ammonia solution is added to adjust the pH to 8.5-9.5, the temperature is raised to 50℃, and the reaction is carried out for 8-12 hours to obtain antimony-doped tin oxide coated with a silica shell. The oxide is separated by centrifugation, washed with anhydrous ethanol, dried under vacuum at 80℃, and then calcined in a muffle furnace at 300-400℃ for 2-4 hours to obtain the final product. The mass ratio of tetraethyl orthosilicate to antimony-doped tin oxide dispersion is (15-25):(1000-1120).

[0012] It should be noted that in the core-shell structure of antimony-doped tin oxide@silica composite nanomaterials, the silica shell has multiple functions. The silica shell effectively inhibits the photocatalytic activity of the antimony-doped tin oxide particles, preventing direct contact between the antimony-doped tin oxide and organic resins that could trigger photo-oxidative degradation, thus significantly improving the coating's weather resistance. The refractive index of the silica shell is lower than that of the antimony-doped tin oxide core. The introduction of the shell reduces the refractive index difference between the particles and the acrylic resin matrix, reducing Rayleigh scattering, thereby maintaining high visible light transmittance and low haze even at higher addition levels. Simultaneously, the silica shell surface is rich in silanol groups, which can condense with the silanol groups of the side chains of the silicone-modified acrylic resin or the end groups of the silane-terminated hyperbranched polyester leveling agent during curing, forming physical and chemical crosslinking points, enhancing the coating's cohesive strength and hardness.

[0013] As a preferred embodiment of the present invention, the preparation method of cesium-doped tungsten oxide@polymer predispersion is as follows: B1. Dissolve sodium tungstate dihydrate in deionized water to obtain solution A; dissolve cesium carbonate in deionized water to obtain solution B; under the conditions of a 50℃ water bath and stirring, add solution B dropwise to solution A, adjust the pH to 1.5-2 with 2mol / L dilute hydrochloric acid, and continue stirring for 2 hours to obtain the precursor sol. The mass ratio of sodium tungstate dihydrate to cesium carbonate is 35:(8-12); In solution A, the mass ratio of sodium tungstate dihydrate to deionized water is 35:150; In solution B, the mass ratio of cesium carbonate to deionized water is (8-12):50; The mass ratio of solution A to solution B is 185:(58-62); B2. The precursor sol obtained in step B1 is transferred to a hydrothermal reactor and hydrothermally reacted at 240℃ for 20h. After naturally cooling to room temperature, it is centrifuged and washed with deionized water until the conductivity of the washing solution is <50μS / cm. It is dried at 80℃ for 12h and then reduced heat treated at 450-500℃ for 1.5h in a mixed atmosphere of nitrogen / hydrogen volume ratio of 95:5 to obtain cesium-doped tungsten oxide nanopowder. The hydrothermal reactor is 70% filled. B3. Dissolve cerium trichloride in deionized water to prepare a cerium trichloride solution, add the cesium-doped tungsten oxide nanoparticles prepared in step B2, ultrasonically disperse for 20-40 min, adjust the pH to 9-10 by adding sodium hydroxide solution dropwise under stirring, react at room temperature for 4-6 h, wash with deionized water, and then calcine in a muffle furnace at 300-400℃ for 1-2 h with a heating rate of 2℃ / min to obtain cerium oxide modified cesium-doped tungsten oxide nanoparticles; The mass ratio of cerium trichloride to deionized water in the cerium trichloride solution is (3-8):(100-200); The mass ratio of cerium trichloride solution to cesium-doped tungsten oxide nanoparticles is (100-210):100; B4. Methyl methacrylate, butyl acrylate, cerium oxide-modified cesium-doped tungsten oxide nanoparticles prepared in step B3, and azobisisobutyronitrile are added to butanone. Under nitrogen atmosphere protection and stirring, the temperature is raised to 75-80℃ and the polymerization reaction is carried out for 4-6 hours. After cooling to room temperature, the precipitate is precipitated in methanol, filtered, washed, and vacuum dried to obtain the cesium-doped tungsten oxide@polymer predispersion. The mass ratio of methyl methacrylate, butyl acrylate, cerium oxide-modified cesium-doped tungsten oxide nanoparticles, azobisisobutyronitrile and butanone is (40-55):(40-55):(5-15):(0.5-1.5):(180-350).

[0014] It should be noted that the cesium-doped tungsten oxide@polymer predispersion features an innovative three-layer structure. First, the cerium oxide modification layer utilizes Ce... 3+ / Ce 4+ Its reversible valence change characteristic preferentially captures photogenerated electrons generated by cesium-doped tungsten oxide under ultraviolet light excitation, preventing W 6+ To W 5+ First, the reduction transformation inhibits photochromism and photocatalytic degradation during coating use. Second, the polymer pre-dispersion shell is formed by in-situ copolymerization of methyl methacrylate and butyl acrylate. Its acrylate backbone structure is highly compatible with organosilicon-modified acrylic resin, enabling the cesium-doped tungsten oxide@polymer pre-dispersion to achieve nanoscale uniform dispersion in the coating composition without additional dispersants, fundamentally solving the problem of poor interfacial compatibility between inorganic nanoparticles and organic resin matrix. Third, the polymer shell and cerium oxide modification layer form a dual protective barrier, blocking the transfer of photogenerated electrons to the cesium tungstate nucleus through both physical isolation and chemical capture, synergistically inhibiting photochemical degradation reactions and significantly extending the service life of the coating under long-term sunlight exposure.

[0015] It should be further explained that the core-shell structured antimony-doped tin oxide@silica composite nanomaterial and cesium-doped tungsten oxide@polymer predispersion exhibit significant synergistic effects in spectral selectivity and photochemical stability. Regarding spectral selectivity, antimony-doped tin oxide primarily blocks long-wave near-infrared thermal radiation, while cesium-doped tungsten oxide primarily blocks short-wave near-infrared thermal radiation; the combination forms a continuous strong absorption band throughout the near-infrared region. In terms of photochemical stability, both utilize two different mechanisms—physical shell isolation (silica) and chemical electron capture (cerium oxide)—to address the photocatalytic activity of the nanoparticles, respectively, resulting in complementary and synergistic effects. When using uncoated antimony-doped tin oxide or unmodified cesium-doped tungsten oxide alone, the UV aging performance of the coating is unsatisfactory; however, after the core-shell and modification treatments of this invention, the combined use of the two significantly improves the gloss retention and color difference stability of the coating after accelerated UV aging.

[0016] As a preferred embodiment of the present invention, the preparation method of the silane-terminated hyperbranched polyester leveling agent is as follows: C1. Dissolve the hydroxyl-terminated hyperbranched polyester in anhydrous tetrahydrofuran, add dibutyltin dilaurate, and stir until homogeneous; The mass ratio of hydroxyl-terminated hyperbranched polyester, anhydrous tetrahydrofuran, and dibutyltin dilaurate is 100:200:0.2. C2. Under nitrogen atmosphere protection and stirring conditions at 40℃, 3-propyltriethoxysilane is added dropwise to the reaction solution obtained in step C1. The addition time is 1 hour. After the addition is completed, the temperature is raised to 60℃ and the reaction continues for 4-6 hours. The mass ratio of hydroxyl-terminated hyperbranched polyester to propyltriethoxysilane 3-isocyanate is 100:(12-18); C3. The solution after the reaction in step C2 is subjected to vacuum distillation at 40℃ and -0.09MPa to remove tetrahydrofuran, washed three times with n-hexane, and dried under vacuum at 50℃ for 12h to obtain silane-terminated hyperbranched polyester leveling agent.

[0017] It should be noted that silane-terminated hyperbranched polyester leveling agents possess both excellent leveling properties and substrate chemical anchoring capabilities. Their hyperbranched molecular structure exhibits low solution viscosity and good wetting and spreading ability, effectively eliminating defects such as brush marks and orange peel on the coating surface. During the coating baking and curing process, the multiple triethoxysilyl groups at the molecular ends undergo condensation reactions with the silanol groups on the glass substrate surface to form Si-O-Si covalent bonds, firmly anchoring the coating to the glass surface. Simultaneously, they can undergo cross-linking condensation with the silanol or alkoxy groups of the organosilicon-modified acrylic resin side chains, constructing an organic-inorganic hybrid cross-linked network within the coating. Through this dual chemical bonding mechanism, a stable chemical interface is formed between the coating and the glass substrate, as well as within the coating itself, significantly improving the coating's adhesion and weather resistance under harsh conditions such as long-term rain erosion and alternating high and low temperatures.

[0018] It should be further explained that there is an interfacial synergistic enhancement effect between the silane-terminated hyperbranched polyester leveling agent and the core-shell structured antimony-doped tin oxide@silica composite nanomaterials. The triethoxysilane end groups of the silane-terminated hyperbranched polyester leveling agent can condense with the silanol groups on the surface of the core-shell structured antimony-doped tin oxide@silica composite nanomaterials, allowing the nanoparticles to be covalently embedded in the coating crosslinking network. This avoids the migration, aggregation, and precipitation problems of nanoparticles due to weak interfacial bonding in traditional physical blending systems, further improving the mechanical properties and durability of the coating.

[0019] As a preferred technical solution of the present invention, the mixed solvent is composed of propylene glycol methyl ether acetate, isopropanol and deionized water, and the mass ratio of propylene glycol methyl ether acetate, isopropanol and deionized water is (6-8):(1-3):(1-2).

[0020] A second aspect of the present invention provides a method for preparing low-emissivity heat-insulating glass containing a functional coating, comprising the following steps: S1. Add the silicone-modified acrylic resin to 40-60% of the total amount of mixed solvent, and stir at 500 r / min for 8-12 min to obtain a resin solution; S2. Add the core-shell structured antimony-doped tin oxide@silica composite nanomaterial and cesium-doped tungsten oxide@polymer predispersant to the resin solution obtained in step S1, and disperse at a high speed of 1000-2000 r / min for 40-60 min to obtain the predispersed slurry. S3. Transfer the pre-dispersed slurry obtained in step S2 into a sand mill, use 0.3mm zirconium beads, and sand mill at 1500-2500r / min for 2-3h until the fineness is ≤5μm to obtain the grinding slurry; S4. Add the remaining mixed solvent to the grinding slurry obtained in step S3, then add silane-terminated hyperbranched polyester leveling agent and silicone defoamer, stir at 800-1200r / min for 10-20min, let stand to defoam, and the functional coating is obtained. S5. Apply the functional coating obtained in step S4 to the clean and dry surface of the automotive glass substrate, level it at room temperature for 10-15 minutes, and bake it at 150℃ for 30 minutes to cure it. The dry film thickness of the coating is 1.5-5μm.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention combines a core-shell structured antimony-doped tin oxide@silica composite nanomaterial with a cesium-doped tungsten oxide@polymer predispersant to achieve broadband near-infrared blocking while ensuring high visible light transmittance of the coating, thus improving the problem of difficulty in achieving both transparency and heat insulation in automotive glass coatings.

[0022] (2) This invention effectively inhibits the photocatalytic activity of nano-functional particles through the synergistic mechanism of physical isolation of the silica shell and chemical electron capture of the cerium oxide modification layer, and significantly extends the service life of the coating in high ultraviolet environment.

[0023] (3) This invention achieves high compatibility and stable dispersion of nanoparticles and acrylic resin matrix by in-situ polymer coating on the surface of cesium-doped tungsten oxide, thereby improving the process problems of easy agglomeration and poor batch consistency when various nanofillers are blended.

[0024] (4) This invention constructs a coating-glass covalent interface and a nanoparticle embedded crosslinking network by chemically bonding a silane-terminated hyperbranched polyester leveling agent with the glass substrate and the surface of the core-shell structured antimony-doped tin oxide@silica composite nanomaterial, thereby improving the durability problem of blistering and peeling of automotive coatings during long-term outdoor use. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Preparation Example 1 The preparation method of core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterials is as follows: A1. By weight, 10 parts of antimony-doped tin oxide nanopowder were added to an ethanol solution consisting of 90 parts of anhydrous ethanol and 10 parts of deionized water, and ultrasonically dispersed for 30 minutes at an ultrasonic power of 300W; the pH was adjusted to 4.5 with glacial acetic acid to obtain an antimony-doped tin oxide dispersion. A2. Under stirring conditions at 25℃, 20 parts of tetraethyl orthosilicate were added dropwise to the antimony-doped tin oxide dispersion prepared in step A1. The dropwise addition time was 1.8 h, and the stirring speed was 300 r / min. After the dropwise addition was completed, 25% ammonia water was added to adjust the pH to 9, the temperature was raised to 50℃, and the reaction was carried out for 10 h to obtain antimony-doped tin oxide with a silica shell. The antimony-doped tin oxide with a silica shell was separated by centrifugation at 8000 r / min for 10 min, washed 3 times with anhydrous ethanol, vacuum dried at 80℃ for 6 h, and then calcined in a muffle furnace at 350℃ for 3 h with a heating rate of 2℃ / min to obtain the final product.

[0027] The antimony-doped tin oxide nanoparticles were purchased from Hangzhou Jiayou New Materials Co., Ltd., item number FF-H10.

[0028] Preparation Example 2 The preparation method of cesium-doped tungsten oxide@polymer predispersion is as follows: B1. By weight, dissolve 35 parts of sodium tungstate dihydrate in 150 parts of deionized water to obtain solution A; dissolve 10 parts of cesium carbonate in 50 parts of deionized water to obtain solution B; under the conditions of a 50°C water bath and stirring, add solution B dropwise to solution A over a period of 1 hour; adjust the pH to 1.8 with 2 mol / L dilute hydrochloric acid, and continue stirring for 2 hours to obtain the precursor sol. B2. The precursor sol obtained in step B1 is transferred to a hydrothermal reactor with a filling degree of 70%. The reactor is hydrothermally reacted at 240℃ for 20 hours, then naturally cooled to room temperature. The sol is centrifuged and washed with deionized water until the conductivity of the washing solution is <50μS / cm. The sol is then dried at 80℃ for 12 hours. Finally, the sol is reduced and heat-treated at 480℃ for 1.5 hours in a mixed atmosphere of nitrogen / hydrogen with a volume ratio of 95:5 to obtain cesium-doped tungsten oxide nanoparticles. B3. Dissolve 5 parts of cerium trichloride in 150 parts of deionized water to prepare a cerium trichloride solution. Add 100 parts of the cesium-doped tungsten oxide nanoparticles prepared in step B2 and ultrasonically disperse for 30 min at an ultrasonic power of 300 W. Adjust the pH to 9.5 by adding 2 mol / L sodium hydroxide solution dropwise under stirring. React at room temperature for 5 h, centrifuge, wash three times with deionized water, dry at 80 °C, and then calcine in a muffle furnace at 350 °C for 1.5 h at a heating rate of 2 °C / min to obtain cerium oxide-modified cesium-doped tungsten oxide nanoparticles. B4. Add 48 parts of methyl methacrylate, 47 parts of butyl acrylate, 10 parts of cerium oxide-modified cesium-doped tungsten oxide nanoparticles prepared in step B3, and 1 part of azobisisobutyronitrile to 265 parts of butanone. Under nitrogen atmosphere protection and stirring, heat to 78°C and polymerize for 5 hours. Cool to room temperature, pour the reaction solution into methanol to precipitate, filter, wash, and vacuum dry at 50°C for 12 hours to obtain the final product.

[0029] Preparation Example 3 The preparation method of silane-terminated hyperbranched polyester leveling agent is as follows: C1. By weight, dissolve 100 parts of hydroxyl-terminated hyperbranched polyester in 200 parts of anhydrous tetrahydrofuran, add 0.2 parts of dibutyltin dilaurate, and stir until homogeneous. C2. Under nitrogen atmosphere protection and stirring conditions at 40°C, 15 parts of 3-propyltriethoxysilane were added dropwise to the reaction solution obtained in step C1. The temperature of the reaction solution was 40°C during the dropwise addition and the dropwise addition time was 1 hour. After the dropwise addition was completed, the temperature was raised to 60°C and the reaction was continued for 5 hours. C3. The solution after the reaction in step C2 is subjected to vacuum distillation at 40℃ and -0.09MPa to remove tetrahydrofuran, washed three times with n-hexane, and dried under vacuum at 50℃ for 12h to obtain the final product.

[0030] Example 1 A low-emissivity heat-insulating glass with a functional coating includes a glass substrate and a functional coating applied to the surface of the glass substrate; the functional coating is formed by applying and curing a functional coating material.

[0031] The raw material composition of functional coatings, by weight, is as follows: 100 parts of silicone-modified acrylic resin; 27.5 parts of core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterials; 11 parts of cesium-doped tungsten oxide@polymer predispersion; 1.8 parts of silane-terminated hyperbranched polyester leveling agent; 0.3 parts of silicone defoamer; 200 parts of mixed solvent.

[0032] The organosilicon-modified acrylic resin is a phenyl organosilicon-modified hydroxyl acrylic resin (ETERAC7361-S, Changxing Chemical), with a solid content of 51%, a hydroxyl value of 68 mgKOH / g, and a silicon content of 8%.

[0033] The mixed solvent consists of propylene glycol methyl ether acetate, isopropanol, and deionized water in a mass ratio of 7:2:1.

[0034] The preparation method includes the following steps: S1. Add the silicone-modified acrylic resin to 50% of the total amount of mixed solvent, stir at 500 r / min for 10 min to obtain a resin solution; S2. The core-shell structured antimony-doped tin oxide@silica composite nanomaterial and cesium-doped tungsten oxide@polymer predispersant are added to the resin solution obtained in step S1 and dispersed at a high speed of 1500 r / min for 50 min to obtain a predispersed slurry. S3. Transfer the pre-dispersed slurry obtained in step S2 into a sand mill, use 0.3mm zirconium beads, and sand mill at 2000r / min for 2.5h until the fineness is ≤5μm to obtain the grinding slurry; S4. Add the remaining mixed solvent to the grinding slurry obtained in step S3, then add silane-terminated hyperbranched polyester leveling agent and silicone defoamer (BYK-024), stir at 1000 r / min for 15 min, let stand to defoam for 30 min, and the functional coating is obtained. S5. Apply the functional coating obtained in step S4 to the clean and dry surface of the automotive windshield substrate (4mm thick) using an air spraying method, control the wet film thickness to make the dry film thickness 3μm; level at room temperature for 12min, bake and cure at 150℃ for 30min to obtain low-emissivity heat-insulating glass with functional coating.

[0035] In this embodiment, some of the raw materials used are the same as those obtained in Preparation Examples 1-3, and the other examples are the same.

[0036] Example 2 The difference between this embodiment and Embodiment 1 is that, by weight, the raw material composition of the functional coating is adjusted as follows: 80 parts of silicone-modified acrylic resin; 20 parts of core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterials; Eight parts of cesium-doped tungsten oxide@polymer predispersion; 0.5 parts of silane-terminated hyperbranched polyester leveling agent; 0.1 parts of silicone defoamer; 150 parts of mixed solvent.

[0037] The preparation method is the same as in Example 1.

[0038] Example 3 The difference between this embodiment and Embodiment 1 is that, by weight, the raw material composition of the functional coating is adjusted as follows: 120 parts of silicone-modified acrylic resin; 35 parts of core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterials; 14 parts of cesium-doped tungsten oxide@polymer predispersion; 3 parts of silane-terminated hyperbranched polyester leveling agent; 0.5 parts of silicone defoamer; 250 parts of mixed solvent.

[0039] The preparation method is the same as in Example 1.

[0040] Comparative Example 1 The difference between this comparative example and Example 1 is that the core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterial prepared in Example 1 was not added; instead, an equal weight of uncoated commercially available antimony-doped tin oxide nanopowder was added.

[0041] Comparative Example 2 The difference between this comparative example and Example 1 is that the cesium-doped tungsten oxide@polymer predispersant prepared in Example 2 was not added; instead, an equal weight of unmodified commercially available cesium-doped tungsten oxide nanoparticles were added.

[0042] The commercially available cesium-doped tungsten oxide nanoparticles were purchased from Hangzhou Jikang New Materials Co., Ltd., product number SS-CW20.

[0043] Comparative Example 3 The difference between this comparative example and Example 1 is that the silane-terminated hyperbranched polyester leveling agent prepared in Preparation Example 3 was not added; instead, an equal part by weight of commercially available polyether-modified silicone leveling agent (BYK-333) was added.

[0044] test: I. Visible Light Transmittance Test Referring to GB / T5137.2-2020 Test Methods for Automotive Safety Glass Part 2: Optical Performance Tests, the visible light transmittance of the coated glass in the 380-780nm wavelength range was determined using an ultraviolet-visible-near-infrared spectrophotometer.

[0045] II. Near-infrared blocking rate test Referring to GB / T5137.2-2020 Test Methods for Automotive Safety Glass Part 2: Optical Performance Tests, the direct transmittance T of the coated glass in the 780-2500nm wavelength band was determined. The transmittance T0 of the uncoated glass substrate in the same batch was used as the benchmark. The near-infrared blocking rate (%) was calculated as [(T0-T) / T0]×100%.

[0046] III. Coating Adhesion Test According to GB / T9286-2021 Paints and Varnishes Cross-cut Test, the coating was subjected to a cross-cut test, and the adhesion level was evaluated after being torn with 3M tape.

[0047] IV. UV Aging Resistance Test Referring to GB / T23987.3-2025 "Laboratory Light Source Exposure Methods for Paints and Varnishes - Part 3: Fluorescent Ultraviolet Lamps", a QUV accelerated aging tester was used with a UVA-340 lamp and an irradiance of 0.89 W / m²·nm. The test involved alternating cycles of 4 hours of illumination at 60℃ and 4 hours of condensation at 50℃. After 1000 hours of testing, the coating appearance was observed. The 60° gloss was measured and the gloss retention rate was calculated according to GB / T9754-2025 "Determination of Gloss at 20°, 60° and 85° for Paints and Varnishes". The color difference ΔE was measured according to GB / T11186-2025 "Method for Measurement of Coating Color".

[0048] V. The test shall be conducted in accordance with GB / T1740-2007, "Determination of Resistance to Damp Heat of Coating Film". The test panels shall be placed in a constant temperature and humidity chamber at 47±1℃ and 96±2% relative humidity for 48 hours, followed by freezing in a -20℃ low-temperature chamber for 2 hours. This constitutes one cycle, and a total of 20 cycles shall be performed. After the test, the test panels shall be removed and visually inspected for any abnormalities such as blistering, cracking, or peeling of the coating.

[0049] VI. Summary of Results Table 1 Test Project Visible light transmittance (%) Near-infrared blocking rate (%) Adhesion (Grade) Appearance after QUV1000h Light retention rate (%) Color difference ΔE Appearance after resistant to damp heat cycling Example 1 78.2 92.5 0 No bubbling, no peeling 91.6 1.5 No bubbling, no cracking, no peeling Example 2 80.5 88.3 0 No bubbling, no peeling 89.8 1.8 No bubbling, no cracking, no peeling Example 3 79.8 94.6 0 No bubbling, no peeling 92.3 1.3 No bubbling, no cracking, no peeling Comparative Example 1 76.8 82.1 0 Slight yellowing 74.5 6.2 Slight bubbling at the edges Comparative Example 2 77.5 79.4 0 Noticeable blue discoloration, slight yellow discoloration 68.2 8.5 Slight bubbling Comparative Example 3 78 91.8 2 Slight bubbling at the edges 80.4 3.6 Obvious blistering and peeling at the edges As shown in Table 1, the low-emissivity heat-insulating glass with functional coatings prepared in Examples 1-3 of the present invention has excellent comprehensive performance.

[0050] In terms of optical performance, the visible light transmittance of Examples 1-3 is all above 75%, and the near-infrared blocking rate is all above 88%, indicating that the coatings meet the light transmittance requirements of automotive windshields while possessing highly efficient near-infrared blocking capabilities. The near-infrared blocking rates of Comparative Examples 1 and 2 are both reduced. This indicates that Examples 1 and 2 of this invention play a crucial role in achieving broad-spectrum near-infrared blocking.

[0051] Regarding adhesion and durability, the adhesion of Examples 1-3 all reached level 0. After QUV accelerated aging, the coating appearance remained intact, and the gloss retention was significantly better than that of the comparative examples, while the color difference ΔE was much lower. Comparative Example 1 showed slight yellowing, decreased gloss retention, and increased color difference, demonstrating that the silica shell layer plays a crucial role in suppressing the photocatalytic activity of antimony-doped tin oxide. Comparative Example 2 showed significant blue discoloration and slight yellowing, with the most severe deterioration in gloss retention and color difference, demonstrating that the cerium oxide modified layer and polymer pre-dispersion shell layer play a crucial role in suppressing the photochromism and photocatalytic degradation of cesium-doped tungsten oxide. Comparative Example 3 used a commercially available ordinary leveling agent instead of the silane-terminated hyperbranched polyester leveling agent, resulting in an adhesion level of 2. After QUV aging, edge blistering and decreased gloss retention occurred, demonstrating the importance of the silane-terminated polyester leveling agent in improving adhesion and weather resistance through chemical bonding.

[0052] In terms of resistance to humid heat cycling, the coatings in Examples 1-3 showed no blistering, cracking, or peeling after 20 cycles of high and low temperature humid heat cycling. Comparative Examples 1 and 2 showed slight blistering to the edges, while Comparative Example 3 showed significant blistering and edge peeling. This further demonstrates that the coating-glass covalent interface and nanoparticle-embedded crosslinking network constructed by the silane-terminated hyperbranched polyester leveling agent effectively improve the interfacial stability and durability of the coating under extreme temperature and humidity cycling conditions.

[0053] In summary, Examples 1-3 of this invention, through the synergistic combination of core-shell structured antimony-doped tin oxide@silica composite nanomaterials, cesium-doped tungsten oxide@polymer predispersants, and silane-terminated hyperbranched polyester leveling agents, successfully achieve a balance between high transparency, high heat insulation, and long lifespan in automotive glass coatings, demonstrating promising prospects for practical applications.

[0054] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the scope defined by the invention, and all such modifications and additions should fall within the protection scope of the present invention.

Claims

1. A low-emissivity heat-insulating glass containing a functional coating, characterized in that: The low-emissivity heat-insulating glass includes a glass substrate and a functional coating applied to the surface of the glass substrate. The functional coating is formed by applying and curing a functional paint. The functional coating comprises the following raw materials by weight: 80-120 parts of silicone-modified acrylic resin; 20-35 parts of core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterials; 8-14 parts of cesium-doped tungsten oxide@polymer predispersion; 0.5-3 parts of silane-terminated hyperbranched polyester leveling agent; 0.1-0.5 parts of silicone defoamer; 150-250 parts of mixed solvent; The preparation method of the cesium-doped tungsten oxide@polymer predispersion is as follows: B1. Dissolve sodium tungstate dihydrate in deionized water to obtain solution A; dissolve cesium carbonate in deionized water to obtain solution B; under the conditions of a 50°C water bath and stirring, add solution B dropwise to solution A, adjust the pH to 1.5-2 with dilute hydrochloric acid, and continue stirring for 2 hours to obtain the precursor sol. B2. The precursor sol obtained in step B1 was hydrothermally reacted at 240℃ for 20h, naturally cooled to room temperature, centrifuged and washed with deionized water until the conductivity of the washing solution was <50μS / cm, dried at 80℃ for 12h, and then reduced heat treated at 450-500℃ for 1.5h in a nitrogen / hydrogen mixed atmosphere to obtain cesium-doped tungsten oxide nanopowder. B3. Dissolve cerium trichloride in deionized water to prepare a cerium trichloride solution, add the cesium-doped tungsten oxide nanoparticles prepared in step B2, ultrasonically disperse for 20-40 min, adjust the pH to 9-10 by adding sodium hydroxide solution dropwise under stirring, react at room temperature for 4-6 h, wash with deionized water, calcine at 300-400℃ for 1-2 h with a heating rate of 2℃ / min to obtain cerium oxide modified cesium-doped tungsten oxide nanoparticles; B4. Methyl methacrylate, butyl acrylate, the cerium oxide-modified cesium-doped tungsten oxide nanoparticles prepared in step B3, and azobisisobutyronitrile are added to butanone. Under nitrogen atmosphere protection and stirring, the temperature is raised to 75-80℃ and the polymerization reaction is carried out for 4-6 hours. After cooling to room temperature, the product is precipitated in methanol, filtered, washed, and vacuum dried to obtain the cesium-doped tungsten oxide@polymer predispersion.

2. The low-emissivity heat-insulating glass with a functional coating according to claim 1, characterized in that: The organosilicon-modified acrylic resin has a solid content of 50±2%, a hydroxyl value of 60-80 mgKOH / g, and a silicon content of 5-10%.

3. The low-emissivity heat-insulating glass with a functional coating according to claim 1, characterized in that: The preparation method of the core-shell structured antimony-doped tin oxide@silicon dioxide composite nanomaterial is as follows: A1. Add the antimony-doped tin oxide nanopowder to an ethanol solution composed of anhydrous ethanol and deionized water, ultrasonically disperse for 20-40 min, and adjust the pH to 4-5 with glacial acetic acid to obtain the antimony-doped tin oxide dispersion. A2. Under stirring conditions at 25℃, tetraethyl orthosilicate is added dropwise to the antimony-doped tin oxide dispersion prepared in step A1 for 1.5-2 hours. After the addition is complete, 25% ammonia solution is added to adjust the pH to 8.5-9.5, the temperature is raised to 50℃, and the reaction is carried out for 8-12 hours to obtain antimony-doped tin oxide coated with a silica shell. The oxide is then separated by centrifugation, washed with anhydrous ethanol, dried under vacuum at 80℃, and calcined in a muffle furnace at 300-400℃ for 2-4 hours to obtain the final product.

4. The low-emissivity heat-insulating glass with a functional coating according to claim 3, characterized in that: In step A1, the mass ratio of the antimony-doped tin oxide nanopowder, anhydrous ethanol, and deionized water is 1:9:1; in step A2, the mass ratio of the tetraethyl orthosilicate to the antimony-doped tin oxide dispersion is (15-25):(1000-1120).

5. The low-emissivity heat-insulating glass with a functional coating according to claim 1, characterized in that: In step B1, in solution A, the mass ratio of sodium tungstate dihydrate to deionized water is 35:150; in solution B, the mass ratio of cesium carbonate to deionized water is (8-12):50; and the mass ratio of solution A to solution B is 185:(58-62).

6. The low-emissivity heat-insulating glass with a functional coating according to claim 1, characterized in that: In step B3, the mass ratio of cerium trichloride to deionized water in the cerium trichloride solution is (3-8):(100-200); the mass ratio of cerium trichloride solution to cesium-doped tungsten oxide nanoparticles is (100-210):100; in step B4, the mass ratio of methyl methacrylate, butyl acrylate, cerium oxide-modified cesium-doped tungsten oxide nanoparticles, azobisisobutyronitrile, and butanone is (40-55):(40-55):(5-15):(0.5-1.5):(180-350).

7. The low-emissivity heat-insulating glass with a functional coating according to claim 1, characterized in that: The preparation method of the silane-terminated hyperbranched polyester leveling agent is as follows: C1. Dissolve the hydroxyl-terminated hyperbranched polyester in anhydrous tetrahydrofuran, add dibutyltin dilaurate, and stir until homogeneous. C2. Under nitrogen atmosphere protection and stirring conditions at 40℃, 3-propyltriethoxysilane is added dropwise to the reaction solution obtained in step C1. The addition time is 1 hour. After the addition is completed, the temperature is raised to 60℃ and the reaction continues for 4-6 hours. C3. The solution after the reaction in step C2 is subjected to vacuum distillation at 40°C and -0.09 MPa to remove tetrahydrofuran, washed three times with n-hexane, and dried under vacuum at 50°C for 12 hours to obtain the silane-terminated hyperbranched polyester leveling agent.

8. The low-emissivity heat-insulating glass with a functional coating according to claim 7, characterized in that: In step C1, the mass ratio of the hydroxyl-terminated hyperbranched polyester, anhydrous tetrahydrofuran, and dibutyltin dilaurate is 100:200:0.2; in step C2, the mass ratio of the hydroxyl-terminated hyperbranched polyester to propyltriethoxysilane 3-isocyanate is 100:(12-18).

9. The low-emissivity heat-insulating glass with a functional coating according to claim 1, characterized in that: The mixed solvent is composed of propylene glycol methyl ether acetate, isopropanol and deionized water, and the mass ratio of propylene glycol methyl ether acetate, isopropanol and deionized water is (6-8):(1-3):(1-2).

10. A method for preparing low-emissivity heat-insulating glass containing a functional coating as described in any one of claims 1-9, characterized in that: Includes the following steps: S1. Add the silicone-modified acrylic resin to 40-60% of the total amount of mixed solvent, and stir at 500 r / min for 8-12 min to obtain a resin solution; S2. Add the core-shell structured antimony-doped tin oxide@silica composite nanomaterial and cesium-doped tungsten oxide@polymer predispersant to the resin solution obtained in step S1, and disperse at a high speed of 1000-2000 r / min for 40-60 min to obtain the predispersed slurry. S3. Transfer the pre-dispersed slurry obtained in step S2 into a sand mill, use 0.3mm zirconium beads, and sand mill at 1500-2500r / min for 2-3h until the fineness is ≤5μm to obtain the grinding slurry; S4. Add the remaining mixed solvent to the grinding slurry obtained in step S3, then add silane-terminated hyperbranched polyester leveling agent and silicone defoamer, stir at 800-1200r / min for 10-20min, let stand to defoam, and the functional coating is obtained. S5. Apply the functional coating obtained in step S4 to the clean and dry surface of the automotive glass substrate, level it at room temperature for 10-15 minutes, and bake it at 150℃ for 30 minutes to cure it.