An automotive heat insulation film and its preparation method

Abstract

The present invention discloses an automotive heat insulation film and a preparation method thereof, belonging to the technical field of heat insulation films. The heat insulation film is prepared by introducing nano-oxides such as indium tin oxide, tungsten oxide, titanium oxide, and zinc oxide, and combining with modified materials. The preparation method includes mixing the nano-oxides with water and ultrasonically dispersing them, adding a coupling agent and modified materials to form a composite slurry, and then mixing with polymers such as polyethylene terephthalate and plasticizers, and drying after coating on the glass surface. Compared with the prior art, the heat insulation film obtained by the present invention not only has excellent optical transparency and heat insulation effect, but also exhibits good mechanical properties and environmental erosion resistance, meeting the strict requirements of modern automobiles for heat insulation and protection performance.

Description

Technical Field

[0001] The present invention relates to the technical field of heat insulation films, and particularly to an automotive heat insulation film and a preparation method thereof. Background Art

[0002] With the increasing global climate change and environmental protection awareness, the automotive industry's demand for heat insulation films is growing day by day. Automotive heat insulation films can not only effectively block solar radiation, reduce the temperature inside the vehicle, but also protect the passengers inside the vehicle from the harm of ultraviolet rays and extend the service life of the materials inside the vehicle. Therefore, developing automotive heat insulation films with excellent heat insulation performance and durability has become an important topic in the industry.

[0003] Existing automotive heat insulation films usually adopt traditional polymer materials, such as polyethylene terephthalate (PET) and polyurethane (PU). Although these materials can meet the heat insulation requirements to a certain extent, their performance still has deficiencies. For example, the tensile strength of traditional polymers is relatively low, and they are prone to aging under high temperature and strong light irradiation, resulting in a decline in the performance of the film. In addition, the ultraviolet absorbers and light stabilizers used in the prior art often fail over time, reducing the protection effect of the film.

[0004] Traditional automotive heat insulation films still have deficiencies in heat insulation performance, mechanical strength and weather resistance. In particular, existing heat insulation films are prone to aging under high temperature and strong light irradiation, resulting in a decline in performance, and the ultraviolet absorbers and light stabilizers used gradually fail over time, weakening the protection effect on the passengers and items inside the vehicle. In addition, the dispersion and compatibility problems of nanomaterials in the polymer matrix in the prior art are also a technical obstacle restricting the improvement of the performance of heat insulation films.

[0005] Chinese invention patent CN105348750A discloses a heat insulation and ultraviolet protection automotive film and a preparation method thereof, using polyethylene terephthalate, polytrimethylene terephthalate, polyimide, molybdenum disulfide, plasticizer, carboxymethyl cellulose, nano-silica, ethylene-α-olefin copolymer, antioxidant and anti-ultraviolet and aging-resistant nanocomposite materials as raw materials. Compared with the prior art, since the nanocomposite material of nano-zinc oxide coated with nano-cerium dioxide has the characteristics of ultraviolet irradiation resistance, heat resistance, non-toxicity and strong stability, and can shield and reflect ultraviolet rays outside the film, the preparation process of this heat insulation and ultraviolet protection automotive film is simple, and it has good heat insulation effect, high temperature resistance, anti-ultraviolet and aging resistance characteristics. The invention also provides a preparation method of an anti-ultraviolet and aging-resistant nanocomposite material, and this anti-ultraviolet and aging-resistant nanocomposite material has good anti-ultraviolet and aging resistance performance. However, it still needs to be improved in terms of heat insulation performance, mechanical strength and weather resistance. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides an automotive heat insulation film prepared with specific nano-oxides and modified materials. This heat insulation film has high tensile strength, infrared and ultraviolet barrier rates, aiming to solve the problems of insufficient performance and poor weather resistance of heat insulation films in the prior art.

[0007] In order to achieve the above-mentioned invention purpose, the present invention adopts the following technical scheme:

[0008] A preparation method of an automotive heat insulation film is as follows, by weight:

[0009] Step 1: Take 0.4 - 0.6 parts of indium tin oxide nano-powder, 0.05 - 0.2 parts of tungsten oxide nano-powder, 0.05 - 0.2 parts of titanium oxide nano-powder, 0.05 - 0.2 parts of zinc oxide nano-powder and 0.05 - 0.2 parts of grinding aid, put them into a ball milling device for mixing and grinding; mix the obtained mixed powder with 4 - 6 parts of water, and perform ultrasonic oscillation to achieve dispersion. Add 0.02 - 0.04 parts of coupling agent and 1 - 1.5 parts of modified material to the dispersion liquid, and stir well to form a uniform composite slurry;

[0010] Step 2: Weigh 1.4 - 1.8 parts of polyethylene terephthalate and 0.1 - 0.3 parts of plasticizer, dissolve them in 15 - 25 parts of ethyl acetate, add 0.05 - 0.2 parts of dispersant, stir to make it evenly dispersed. Add 15 - 25 parts of water to the mixture, continue to stir, and remove ethyl acetate through the distillation process. Add 0.01 - 0.015 parts of ethylene-vinyl acetate copolymer, 0.005 - 0.02 parts of ultraviolet absorber, 0.001 - 0.003 parts of light stabilizer 770, 0.004 - 0.06 parts of BYK-310 leveling agent, 0.0005 - 0.002 parts of silicone defoamer, and mix until it is in a uniform state to obtain a mixture; add the composite slurry obtained in Step 1 to the above mixture, stir well, and evaporate the water to prepare a mixed slurry for coating;

[0011] Step 3: Uniformly coat the mixed slurry obtained in Step 2 on the glass surface to obtain a coating. Place the coated glass in an oven for drying until the solvent in the slurry completely volatilizes to obtain an automotive heat insulation film.

[0012] The grinding aid is sodium citrate.

[0013] The time of the ultrasonic oscillation is 40 - 60 minutes, the ultrasonic power is 200 - 400 W, and the ultrasonic frequency is 20 - 60 kHz.

[0014] The coupling agent is isopropyl tris(dioctylpyrophosphate) titanate.

[0015] The plasticizer is polyisobutylene.

[0016] The dispersant is polyvinylpyrrolidone.

[0017] The evaporated water content is such that the solid content reaches 70-80%.

[0018] The wet film thickness of the coating is controlled at 0.15-0.25 mm.

[0019] The preparation method of the modified material is as follows, by weight:

[0020] S1. Weigh 0.01-0.03 parts of benzoyl peroxide, mix it with 4-6 parts of ethyl acetate, and stir until uniform to obtain an initiator solution.

[0021] S2. Weigh 5-10 parts of 1,1,2,2-tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane and 8-10 parts of (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid, add them to 25-35 parts of ethyl acetate, heat to 60-80 °C and keep for 10-20 minutes, dropwise add the initiator solution of step S1, raise the temperature to 90-110 °C, and keep for 1-2 hours to obtain a pretreatment product.

[0022] S3. Mix the pretreatment product obtained in step S2, 30-50 parts of polyurethane resin, and 0.05-0.1 part of hexamethylene diisocyanate, heat to 50-70 °C, and keep for 40-60 minutes to obtain the modified material.

[0023] In the preparation method of the automotive heat insulation film of the present invention, the functions of each substance are as follows:

[0024] The indium tin oxide nanopowder is used as part of the heat insulation film. Indium tin oxide nanopowder has good optical properties and heat insulation effects.

[0025] The tungsten oxide nanopowder increases the wear resistance and scratch resistance of the film, and at the same time improves the heat insulation performance.

[0026] The titanium oxide nanopowder improves the weather resistance and ultraviolet resistance of the film.

[0027] The zinc oxide nanopowder has antibacterial and ultraviolet resistance functions, enhancing the protection performance of the heat insulation film.

[0028] Sodium citrate is used as a grinding aid to help the nanopowders mix and grind better.

[0029] Isopropyltri(dioctylpyrophosphato)titanate is used as a coupling agent to improve the compatibility and bonding force between inorganic nanopowders and organic polymers.

[0030] The modified material improves the overall performance of the heat insulation film, such as tensile strength, heat resistance, and optical properties, through specific chemical reactions and polymerization processes.

[0031] Polyethylene terephthalate serves as the matrix material of the heat insulation film, providing good optical transparency and mechanical properties.

[0032] Polyisobutylene acts as a plasticizer to improve the flexibility and processability of the film.

[0033] Polyvinylpyrrolidone acts as a dispersant to help other components disperse evenly in the solution.

[0034] Ethylene-vinyl acetate copolymer improves the flexibility and adhesion properties of the film.

[0035] The ultraviolet absorber absorbs ultraviolet light to protect the heat insulation film from ultraviolet damage.

[0036] Light stabilizer 770 improves the light resistance of the film and prevents photoaging.

[0037] BYK-310 leveling agent improves the surface quality of the coating, making it smoother and flatter.

[0038] Organic silicone defoamer reduces the bubbles generated during the coating process and improves the clarity of the film.

[0039] Benzoyl peroxide acts as a free radical initiator to initiate the polymerization reaction.

[0040] 1,1,2,2-Tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane provides fluorine atoms to increase the chemical stability and weather resistance of the material.

[0041] (2Z)-3-(Cyclopropylcarbamoyl)acrylic acid provides a carbamoyl group to enhance the crosslinking density and mechanical strength of the material.

[0042] Polyurethane resin serves as the matrix of the modified material, providing excellent mechanical properties and chemical resistance.

[0043] Hexamethylene diisocyanate acts as a crosslinking agent to increase the crosslinking density and three-dimensional network structure of the material, enhancing its heat resistance and mechanical properties.

[0044] Compared with the prior art, it has the following beneficial effects:

[0045] 1) By introducing specific nano-oxides and modified materials, the present invention effectively improves the infrared and ultraviolet barrier rates of the automotive heat insulation film, enhances the reflection and absorption capabilities of the film to solar heat energy, thereby more effectively blocking external heat from entering the vehicle and improving the heat insulation efficiency.

[0046] 2) By combining nano-oxides with modified materials and adopting a specific preparation method, the final heat-insulating film of the present invention has higher tensile strength. This enhanced mechanical property helps to improve the durability and impact resistance of the film, extend its service life, and ensure the maintenance of its function and integrity under various usage conditions.

[0047] 3) The preparation method of the heat-insulating film of the present invention uses more environmentally friendly materials and processes. This not only reduces the impact on the environment, but also, due to the improved heat-insulating performance, helps to reduce the energy consumption of the in-vehicle air conditioner, thereby saving energy and reducing carbon emissions. In addition, by controlling the ultraviolet light blocking rate of the film, the present invention also helps to protect the in-vehicle passengers from the harm of ultraviolet light and protect the vehicle interior decorations from fading or aging caused by ultraviolet light. Detailed implementation mode

[0048] Main sources of substances:

[0049] Indium tin oxide nano-powder: average particle size: 30 nm, purity: 99.9%, specific surface area: 35 m 2 / g, crystal form: spherical, color: light blue.

[0050] Tungsten oxide nano-powder: content ≥ 99.9%, particle size: 50 nm, appearance: blue.

[0051] Titanium oxide nano-powder: average particle size: 100 nm, purity: 99.9%, crystal form: rutile, color: white.

[0052] Zinc oxide nano-powder: particle size: 30 - 50 nm, appearance: white powder, content: 99.7%.

[0053] Isopropyl tri(dioctylpyrophosphato) titanate: CAS: 67691-13-8, chemical formula: C 51 H 112 O 22 P 6 Ti, molecular weight: 1311.13.

[0054] Polyethylene terephthalate: brand: DuPont of the United States, specification model: 545NC010.

[0055] Polyisobutylene: brand: Daelim of South Korea, molecular weight: 950, viscosity at 100°C (cst): 230 ± 10, pour point °C: -9 ± 5, flash point °C: 190.

[0056] Polyvinylpyrrolidone: product number: PVP K30, Jinhai Iodine (Shandong) New Material Technology Co., Ltd.

[0057] Ethylene-vinyl acetate copolymer: manufacturer (origin): Hanwha of South Korea, product name: EVA.

[0058] Ultraviolet absorber: Single product item number: uv-531, Dongguan Dinghai Plastic Chemical Co., Ltd.

[0059] Light stabilizer 770: CAS: 52829-07-9, Brand: Senfeida.

[0060] BYK-310 leveling agent: Brand: BYK.

[0061] Organic silicon defoamer: Item number: CI-0560, Guangdong Nanhui New Materials Co., Ltd.

[0062] Polyurethane resin: Model: Neorez R3986, Content ≥ 35(%), Density: 1.4(g / cm 3 ), Shanghai Youci New Materials Co., Ltd.

[0063] 1,1,2,2-Tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane: CAS No.: 1998-53-4 Molecular formula: C 6 F 10 O 2 .

[0064] (2Z)-3-(Cyclopropylcarbamoyl)prop-2-enoic acid: CAS No.: 27995-78-4, Molecular formula: C 7 H 9 NO 3 .

[0065] Perfluoro-3-oxabutyl vinyl ether: CAS No.: 39499-31-5 Molecular formula: C 5 F 10 O 2 .

[0066] Perfluoroethyl vinyl ether: CAS No.: 10493-43-3 Molecular formula: C 4 F 8 O.

[0067] Tetrafluoroethylene: CAS No.: 116-14-3 Molecular formula: C 2 F 4 .

[0068] 2-Methyl-N-[3-(trimethoxysilyl)propyl]-2-propenamide: CAS No.: 10310-41-5 Molecular formula: C 10 H 21 NO 4 Si.

[0069] Triethoxysilylpropyl maleic acid: CAS No.: 33525-68-7 Molecular formula: C 13 H 25 NO6 Si.

[0070] Vinyltriethoxysilane: CAS No.: 78-08-0 Molecular formula: C 8 H 18 O 3 Si.

[0071] The remaining raw materials in the examples and comparative examples of the present invention are all commercially available products.

[0072] The design idea of the present invention is to prepare an automotive heat insulation film with excellent heat insulation performance and mechanical strength. By combining nano-oxide powders with specific modification materials, and using ultrasonic oscillation technology to achieve uniform dispersion of the powders, and then mixing with polymers such as polyethylene terephthalate and polyisobutylene to form a high-performance composite slurry. In this process, 1,1,2,2-tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane and (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid are specifically selected as the key components of the modification materials to enhance the tensile strength of the film and the barrier rates of infrared and ultraviolet light. This modification material not only improves the optical properties and weather resistance of the heat insulation film, but also enhances its ability to absorb and reflect ultraviolet light by introducing fluorine atoms, thereby effectively controlling the temperature inside the vehicle, improving the riding comfort, and reducing energy consumption. In addition, this preparation method also considers environmental protection factors, avoiding the use of substances harmful to the environment, and meeting the current requirements for green materials.

[0073] Example 1

[0074] A preparation method of an automotive heat insulation film is as follows:

[0075] Step 1: Take 0.5 kg of indium tin oxide nano-powder, 0.1 kg of tungsten oxide nano-powder, 0.1 kg of titanium oxide nano-powder, 0.1 kg of zinc oxide nano-powder and 0.1 kg of sodium citrate, and put them into a ball milling device for mixing and grinding; mix the obtained mixed powder with 5 kg of water, and perform ultrasonic oscillation for 50 minutes to achieve dispersion, the ultrasonic power is 300 W, and the ultrasonic frequency is 40 kHz. Add 0.03 kg of isopropyltri(dioctylpyrophosphato)titanate and 1.2 kg of modification material to the dispersion liquid, and stir well to form a uniform composite slurry;

[0076] Step 2: Weigh 1.6 kg of polyethylene terephthalate and 0.2 kg of polyisobutene, dissolve them in 20 kg of ethyl acetate, add 0.1 kg of polyvinylpyrrolidone, stir to make it evenly dispersed, add 20 kg of water to the mixture, continue to stir, and remove ethyl acetate through the distillation process. Then add 0.012 kg of ethylene-vinyl acetate copolymer, 0.01 kg of ultraviolet absorber, 0.002 kg of light stabilizer 770, 0.005 kg of BYK-310 leveling agent, and 0.001 kg of silicone defoamer, and mix until it reaches a uniform state to obtain a mixture; add the composite slurry obtained in Step 1 to the above mixture, stir well, and evaporate water to make the solid content reach 75%, thereby preparing a mixed slurry for coating;

[0077] Step 3: Uniformly coat the mixed slurry obtained in Step 2 on the glass surface, control the wet film thickness of the coating at 0.18 mm, place the coated glass in an oven for drying until the solvent in the slurry is completely volatilized to obtain an automotive heat insulation film.

[0078] The preparation method of the modified material is as follows:

[0079] S1: Weigh 0.02 kg of benzoyl peroxide, mix it with 5 kg of ethyl acetate, and stir until it is uniform to obtain an initiator solution;

[0080] S2: Weigh 8 kg of 1,1,2,2-tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane and 9 kg of (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid, add them to 30 kg of ethyl acetate, heat to 70 °C and keep for 15 minutes, dropwise add the initiator solution in Step S1, raise the temperature to 100 °C, and keep for 1.5 hours to obtain a pretreatment product;

[0081] S3: Mix the pretreatment product obtained in Step S2, 40 kg of polyurethane resin, and 0.08 kg of hexamethylene diisocyanate, heat to 60 °C, and keep for 50 minutes to obtain a modified material.

[0082] Example 2

[0083] A preparation method of an automotive heat insulation film is basically the same as that in Example 1, and the only difference lies in the preparation method of the modified material.

[0084] The preparation method of the modified material is as follows:

[0085] S1: Weigh 0.02 kg of benzoyl peroxide, mix it with 5 kg of ethyl acetate, and stir until it is uniform to obtain an initiator solution;

[0086] S2. Weigh 8 kg of perfluoro-3-oxabutyl vinyl ether and 9 kg of (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid, add them to 30 kg of ethyl acetate, heat to 70 °C and keep for 15 minutes, dropwise add the initiator solution in step S1, raise the temperature to 100 °C, and keep for 1.5 hours to obtain a pretreatment product;

[0087] S3. Mix the pretreatment product obtained in step S2, 40 kg of polyurethane resin, and 0.08 kg of hexamethylene diisocyanate, heat to 60 °C, and keep for 50 minutes to obtain a modified material.

[0088] Example 3

[0089] A method for preparing an automotive heat insulation film is basically the same as that in Example 1, and the only difference lies in the different preparation methods of the modified material.

[0090] The preparation method of the modified material is as follows:

[0091] S1. Weigh 0.02 kg of benzoyl peroxide, mix it with 5 kg of ethyl acetate, and stir until uniform to obtain an initiator solution;

[0092] S2. Weigh 8 kg of perfluoroethyl vinyl ether and 9 kg of (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid, add them to 30 kg of ethyl acetate, heat to 70 °C and keep for 15 minutes, dropwise add the initiator solution in step S1, raise the temperature to 100 °C, and keep for 1.5 hours to obtain a pretreatment product;

[0093] S3. Mix the pretreatment product obtained in step S2, 40 kg of polyurethane resin, and 0.08 kg of hexamethylene diisocyanate, heat to 60 °C, and keep for 50 minutes to obtain a modified material.

[0094] Example 4

[0095] A method for preparing an automotive heat insulation film is basically the same as that in Example 1, and the only difference lies in the different preparation methods of the modified material.

[0096] The preparation method of the modified material is as follows:

[0097] S1. Weigh 0.02 kg of benzoyl peroxide, mix it with 5 kg of ethyl acetate, and stir until uniform to obtain an initiator solution;

[0098] S2. Weigh 8 kg of 1,1,2,2 - tetrafluoro - 1,2 - bis[(trifluorovinyl)oxy]ethane and 9 kg of 2 - methyl - N - [3 - (trimethoxysilyl)propyl] - 2 - acrylamide, add them to 30 kg of ethyl acetate, heat to 70 °C and keep for 15 minutes, dropwise add the initiator solution in step S1, raise the temperature to 100 °C, and keep for 1.5 hours to obtain a pretreated product;

[0099] S3. Mix the pretreated product obtained in step S2, 40 kg of polyurethane resin, and 0.08 kg of hexamethylene diisocyanate, heat to 60 °C, and keep for 50 minutes to obtain a modified material.

[0100] Example 5

[0101] A method for preparing an automotive heat - insulating film is basically the same as that in Example 1, and the only difference lies in the preparation method of the modified material.

[0102] The preparation method of the modified material is as follows:

[0103] S1. Weigh 0.02 kg of benzoyl peroxide, mix it with 5 kg of ethyl acetate, and stir until uniform to obtain an initiator solution;

[0104] S2. Weigh 8 kg of 1,1,2,2 - tetrafluoro - 1,2 - bis[(trifluorovinyl)oxy]ethane and 9 kg of vinyltriethoxysilane, add them to 30 kg of ethyl acetate, heat to 70 °C and keep for 15 minutes, dropwise add the initiator solution in step S1, raise the temperature to 100 °C, and keep for 1.5 hours to obtain a pretreated product;

[0105] S3. Mix the pretreated product obtained in step S2, 40 kg of polyurethane resin, and 0.08 kg of hexamethylene diisocyanate, heat to 60 °C, and keep for 50 minutes to obtain a modified material.

[0106] Comparative Example 1

[0107] A method for preparing an automotive heat - insulating film is basically the same as that in Example 1, and the only difference lies in the preparation method of the modified material.

[0108] The preparation method of the modified material is as follows:

[0109] S1. Weigh 0.02 kg of benzoyl peroxide, mix it with 5 kg of ethyl acetate, and stir until uniform to obtain an initiator solution;

[0110] S2. Weigh 8 kg of tetrafluoroethylene and 9 kg of (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid, add them to 30 kg of ethyl acetate, heat to 70 °C and maintain for 15 minutes, dropwise add the initiator solution from step S1, raise the temperature to 100 °C, and maintain for 1.5 hours to obtain a pretreatment product;

[0111] S3. Mix the pretreatment product obtained in step S2, 40 kg of polyurethane resin, and 0.08 kg of hexamethylene diisocyanate, heat to 60 °C, and maintain for 50 minutes to obtain a modified material.

[0112] Comparative Example 2

[0113] A method for preparing an automotive heat insulation film is basically the same as that of Example 1, and the only difference lies in the different preparation methods of the modified material.

[0114] The preparation method of the modified material is as follows:

[0115] S1. Weigh 0.02 kg of benzoyl peroxide, mix it with 5 kg of ethyl acetate, and stir until uniform to obtain an initiator solution;

[0116] S2. Weigh 8 kg of 1,1,2,2-tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane and 9 kg of triethoxysilylpropyl maleate, add them to 30 kg of ethyl acetate, heat to 70 °C and maintain for 15 minutes, dropwise add the initiator solution from step S1, raise the temperature to 100 °C, and maintain for 1.5 hours to obtain a pretreatment product;

[0117] S3. Mix the pretreatment product obtained in step S2, 40 kg of polyurethane resin, and 0.08 kg of hexamethylene diisocyanate, heat to 60 °C, and maintain for 50 minutes to obtain a modified material.

[0118] Comparative Example 3

[0119] A method for preparing an automotive heat insulation film is basically the same as that of Example 1, and the only difference lies in the different preparation methods of the modified material.

[0120] The preparation method of the modified material is as follows:

[0121] S1. Weigh 0.02 kg of benzoyl peroxide, mix it with 5 kg of ethyl acetate, and stir until uniform to obtain an initiator solution;

[0122] S2. Weigh 8 kg of tetrafluoroethylene and 9 kg of triethoxysilylpropyl maleate, add them to 30 kg of ethyl acetate, heat to 70 °C and maintain for 15 minutes, dropwise add the initiator solution from step S1, raise the temperature to 100 °C, and maintain for 1.5 hours to obtain a pretreatment product;

[0123] S3. Mix the pre-treated product obtained in step S2, 40 kg of polyurethane resin, and 0.08 kg of hexamethylene diisocyanate, heat to 60 °C, and maintain for 50 minutes to obtain a modified material.

[0124] Comparative Example 4

[0125] A method for preparing an automotive heat insulation film is as follows:

[0126] Step 1. Take 0.5 kg of indium tin oxide nanometer powder, 0.1 kg of tungsten oxide nanometer powder, 0.1 kg of titanium oxide nanometer, 0.1 kg of zinc oxide nanometer powder, and 0.1 kg of sodium citrate, put them into a ball milling device for mixing and grinding; mix the obtained mixed powder with 5 kg of water, and perform ultrasonic oscillation for 50 minutes to achieve dispersion, with an ultrasonic power of 300 W and an ultrasonic frequency of 40 kHz. Add 0.03 kg of isopropyltri(dioctylpyrophosphato) titanate and 1.2 kg of polyurethane resin to the dispersion liquid, and stir well to form a uniform composite slurry.

[0127] Step 2. Weigh 1.6 kg of polyethylene terephthalate and 0.2 kg of polyisobutylene, dissolve them in 20 kg of ethyl acetate, add 0.1 kg of polyvinylpyrrolidone, stir to make it evenly dispersed, add 20 kg of water to the mixture, continue stirring, and remove ethyl acetate through the distillation process. Add 0.012 kg of ethylene-vinyl acetate copolymer, 0.01 kg of ultraviolet absorber, 0.002 kg of light stabilizer 770, 0.005 kg of BYK-310 leveling agent, and 0.001 kg of silicone defoaming agent, and mix until it reaches a uniform state to obtain a mixture; add the composite slurry obtained in step 1 to the above mixture, stir well, and evaporate water to make the solid content reach 75% to prepare a mixed slurry for coating.

[0128] Step 3. Evenly coat the mixed slurry obtained in step 2 on the glass surface, control the wet film thickness of the coating to be 0.18 mm, place the coated glass in an oven for drying until the solvent in the slurry completely volatilizes to obtain an automotive heat insulation film.

[0129] Test Example 1

[0130] The tensile strength is measured with reference to GB / T 1040.3-2006 "Determination of Tensile Properties of Plastics - Part 3: Test Conditions for Films and Sheets".

[0131] The test results are shown in Table 1.

[0132] Table 1

[0133] Experimental Scheme Tensile Strength (MPa) Example 1 48.4 Example 2 45.6 Example 3 44.1 Example 4 44.8 Example 5 45.6 Comparative Example 1 42.7 Comparative Example 2 44.5 Comparative Example 3 41.7 Comparative Example 4 37.9

[0134] Test Example 2

[0135] According to the standard of QC / T 1170-2022 "Functional Films for Automotive Glass", the performance test of the heat-insulating film of the present invention includes the following two parts:

[0136] 1. Infrared barrier efficiency evaluation: This test uses a Hitachi U-4100 type spectroscopic analysis instrument to measure the transmittance of the heat-insulating film samples of Examples 1 to 5 and Comparative Examples 1 to 4 of the present invention in the near-infrared region of the solar spectrum, that is, at wavelengths from 1400 nm to 2500 nm. According to the obtained transmittance data, the infrared barrier rate of each sample is calculated.

[0137] 2. Ultraviolet barrier efficiency evaluation: This test also uses a Hitachi U-4100 type spectroscopic analysis instrument to measure the transmittance of the above samples in the ultraviolet region of the solar spectrum, that is, at wavelengths from 300 nm to 380 nm. According to the measurement results, the ultraviolet barrier rate of each sample is further calculated.

[0138] The test results are shown in Table 2.

[0139] Table 2

[0140] Experimental Scheme Infrared Blocking Rate (%) Ultraviolet Blocking Rate (%) Example 1 93.6 98.4 Example 2 91.5 96.1 Example 3 91.0 95.4 Example 4 90.6 95.2 Example 5 90.2 94.3 Comparative Example 1 89.1 93.0 Comparative Example 2 89.9 94.7 Comparative Example 3 87.3 92.5 Comparative Example 4 82.6 89.7

[0141] It can be seen from the data in Tables 1-2 that the test results of the tensile strength, infrared barrier rate and ultraviolet barrier rate of the automotive heat-insulating film prepared in Example 1 are the best.

[0142] In Example 1 of the present invention, 1,1,2,2-tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane adopted has a symmetric structure, which makes the intermolecular interaction force stronger, thereby improving the physical properties of the polymer. The two double bonds in this compound provide additional reactive sites, which contribute to the formation of a more stable cross-linked network during the polymerization process. This highly ordered and compact molecular structure not only enhances the tensile strength of the material, but also improves the barrier efficiency against infrared and ultraviolet light. Due to the high electronegativity of fluorine atoms, this structure also helps to improve the optical transparency and chemical resistance of the material, which is crucial for the performance of automotive heat-insulating films. Therefore, compared with other examples and comparative examples, the materials in Example 1 exhibit more excellent comprehensive properties, including higher tensile strength and better infrared and ultraviolet barrier rates.

[0143] The (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid used in Example 1 has a specific molecular structure, including a cyclopropylcarbamoyl group and an acrylic double bond. This structure provides excellent reactivity and crosslinking ability. The presence of the cyclopropyl group increases the rigidity and stability of the molecule. In addition, the presence of the acrylic double bond allows this molecule to copolymerize with other monomers, further enhancing the crosslinking density and network structure of the polymer. The combination of this structure not only improves the tensile strength of the modified material but also enhances its barrier ability to infrared and ultraviolet light. Therefore, compared with other monomers used in Examples 4 and 5 and with triethoxysilylpropyl maleic acid in Comparative Example 2, the (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid in Example 1 provides better comprehensive performance, resulting in an automotive heat-insulating film with higher tensile strength, infrared barrier rate, and ultraviolet barrier rate.

[0144] In Example 1, the modified material achieved excellent tensile strength, infrared barrier rate, and ultraviolet barrier rate by combining 1,1,2,2-tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane and (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid. The fluorine atoms in 1,1,2,2-tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane provide a strong electron-withdrawing ability, enhancing the van der Waals forces between molecules, thereby improving the cohesion and tensile strength of the material. At the same time, the high electronegativity of the fluorine atoms helps to block ultraviolet and infrared rays because the fluorine atoms can absorb the light energy in these spectral regions. On the other hand, the introduction of (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid not only increases the rigidity of the molecule, but its cyclopropyl structure can also improve the heat resistance and chemical resistance of the material, while the carbamoyl group enhances the intermolecular hydrogen bonding, further improving the mechanical properties of the material. The synergistic effect of these two components enables the modified material to effectively block ultraviolet and infrared rays while maintaining high transparency, thus outperforming the directly used polyurethane resin in terms of performance and making it more suitable for the application of high-performance automotive heat-insulating films.

Claims

1. A method for preparing an automobile thermal insulation film, characterized in that: The method is as follows, in parts by weight: Step 1, taking 0.4-0.6 parts of nano indium tin oxide powder, 0.05-0.2 parts of nano tungsten oxide powder, 0.05-0.2 parts of nano titanium oxide, 0.05-0.2 parts of nano zinc oxide powder and 0.05-0.2 parts of grinding aid, putting them into a ball mill for mixing and grinding; mixing the obtained mixed powder with 4-6 parts of water, and performing ultrasonic vibration to achieve dispersion, adding 0.02-0.04 parts of coupling agent and 1-1.5 parts of modified material to the dispersion, and stirring them fully to form a uniform composite slurry; Step 2, weighing 1.4-1.8 parts of polyethylene terephthalate and 0.1-0.3 parts of plasticizer, dissolving them in 15-25 parts of ethyl acetate, adding 0.05-0.2 parts of dispersant, stirring to make it uniformly dispersed, adding 15-25 parts of water to the mixture, continuing to stir, and removing ethyl acetate through a distillation process, adding 0.01-0.015 parts of ethylene-vinyl acetate copolymer, 0.005-0.02 parts of ultraviolet absorber, 0.001-0.003 parts of light stabilizer 770, 0.004-0.06 parts of BYK-310 leveling agent, 0.0005-0.002 parts of silicone defoamer, mixing until a uniform state, to obtain a mixture; adding the composite slurry obtained in step 1 to the above mixture, stirring fully, and evaporating the water to prepare a mixed slurry for coating; Step 3, evenly coating the mixed slurry obtained in step 2 on the glass surface to obtain a coating, placing the coated glass in an oven for drying until the solvent in the slurry is completely volatilized to obtain a car thermal insulation film; The preparation method of the modified material is as follows, in parts by weight: S1. Weigh 0.01-0.03 parts of dibenzoyl peroxide, mix it with 4-6 parts of ethyl acetate, and stir until uniform to obtain an initiator solution; S2, weigh 5 to 10 parts of 1,1,2,2-tetrafluoro-1,2-bis[(trifluorovinyl)oxy]ethane and 8 to 10 parts of (2Z)-3-(cyclopropylcarbamoyl)prop-2-enoic acid, add them to 25 to 35 parts of ethyl acetate, heat to 60 to 80° C. and keep for 10 to 20 minutes, add the initiator solution of step S1 dropwise, raise the temperature to 90 to 110° C., keep for 1 to 2 hours, and obtain a pretreated product; S3, mixing the pretreated material obtained in step S2, 30-50 parts of polyurethane resin, and 0.05-0.1 parts of hexamethylene diisocyanate, heating to 50-70° C., and maintaining for 40-60 minutes to obtain a modified material.

2. The method for preparing the automotive thermal insulation film according to claim 1, characterized in that: The grinding aid is sodium citrate.

3. The method for preparing the automotive thermal insulation film according to claim 1, wherein the ultrasonic oscillation time is 40 to 60 minutes, the ultrasonic power is 200 to 400 W, and the ultrasonic frequency is 20 to 60 kHz.

4. The method for preparing an automotive thermal insulation film according to claim 1, wherein the coupling agent is isopropyl tri(dioctyl pyrophosphate) titanate.

5. The method for preparing the automotive thermal insulation film according to claim 1, wherein the plasticizer is polyisobutylene. 6 . The method for preparing the automotive thermal insulation film according to claim 1 , wherein the dispersant is polyvinyl pyrrolidone.

7. The method for preparing the automotive thermal insulation film according to claim 1, wherein the evaporated water is such that the solid content reaches 70-80%.

8. The method for preparing an automotive thermal insulation film according to claim 1, wherein the wet film thickness of the coating is controlled to be 0.15-0.25 mm.

9. A car thermal insulation film, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.