Coating with optical colorful effect, protective layer using coating and application

Abstract

The invention relates to a coating with an optical colorful effect, a protective layer applying the coating and application, and relates to the technical field of automobile material processing. Preparation raw materials comprise the following components in parts by mass: 45 to 55 parts of photochromic material loaded porous core-shell structure nanoparticles, 8 to 12 parts of silver nanorods, 15 to 20 parts of acrylic resin, 1 to 2 parts of a surfactant, 0.5 to 1 part of glutaraldehyde, 0.1 to 0.3 part of glacial acetic acid, 0.5 to 1.5 parts of a fluorocarbon silane coupling agent and 30 to 40 parts of a solvent. The protective layer comprises a fluorocarbon hydrophobic protective layer, a self-repairing layer and an optical colorful layer which are arranged in sequence, and the protective layer is applied to the color-changing self-repairing car cover. The coating prepared by the invention has the effect of beautifying and self-repairing the appearance of the car cover, and the car cover presents an appearance with an optical colorful effect and also has good tensile property, aging resistance and self-repairing performance.

Description

Technical Field

[0001] The present application relates to the technical field of automotive material processing, and in particular to a coating with an optical dazzling effect, a protective layer using the coating, and an application thereof. Background Art

[0002] With the growth of personalized needs for automobiles, color-changing car wraps that combine the functions of appearance color change and paint protection have gradually become the mainstream in the market. Although traditional color-changing films (such as those made of PVC material) can achieve color diversification, they have problems such as easy fading, weak anti-scratch ability, lack of self-healing function, etc., and cannot effectively resist environmental erosion such as ultraviolet rays and acid rain. While invisible car wraps (made of TPU material) have excellent impact resistance and self-healing performance, they are mostly transparent or single-toned, making it difficult to meet consumers' demands for dazzling visual effects.

[0003] However, the combination of color change and self-healing functions faces multiple technical challenges. The introduction of optical dazzling components easily leads to the destruction of the coating cross-linking network, resulting in a decrease in self-healing efficiency, and it is difficult to balance aesthetics and self-healing function. Therefore, it is necessary to develop a coating with an optical dazzling effect and a protective layer using the coating, so that the car wrap can have both good aesthetics and self-healing performance. Summary of the Invention

[0004] In order to improve the aesthetics and functionality of the car wrap, the present application provides a coating with an optical dazzling effect, a protective layer using the coating, and an application thereof.

[0005] The coating with an optical dazzling effect, a protective layer using the coating, and an application thereof provided by the present application adopt the following technical solutions: In the first aspect, the coating with an optical dazzling effect provided by the present application adopts the following technical solutions: A coating with an optical dazzling effect, the preparation raw materials of which include the following components in parts by mass: 45 - 55 parts of porous core-shell structure nanoparticles loaded with color-changing materials 8 - 12 parts of silver nanorods 15 - 20 parts of acrylic resin 1 - 2 parts of surfactant 0.5 - 1 part of glutaraldehyde 0.1 - 0.3 part of glacial acetic acid 0.5 - 1.5 parts of fluorocarbon silane coupling agent 30 - 40 parts of solvent.

[0006] The loadable color-changing material porous core-shell structure nanoparticles construct a three-dimensional photonic crystal framework. The porous core-shell structure has nanoscale light scattering characteristics, which can realize the regulation of the color of the photochromic material and provide an optical dazzling effect. Its mesoporous structure forms a nanoscale interpenetrating network with silver nanorods, and the tensile strength is improved through the interfacial friction energy dissipation mechanism. The surface plasmon resonance effect of silver nanorods and the conjugated double bonds of acrylic resin form a photo-thermal synergistic barrier, which improves the ultraviolet absorption rate and simultaneously inhibits the molecular chain degradation caused by free radicals. Glutaraldehyde forms dynamic Schiff base cross-linking bonds with the amino groups in acrylic resin, and can achieve room temperature self-healing through hydrogen bond recombination after breaking at the scratch. Glacial acetic acid adjusts the pH of the system to a weakly acidic environment, which promotes the formation of a dense silver oxide antibacterial layer on the surface of silver nanorods, and at the same time optimizes the dispersion of core-shell particles and improves the uniformity of the coating with an optical dazzling effect. The flexible shell layer of the core-shell particles and the rigid core layer of silver nanorods form a gradient mechanical structure, which absorbs energy through delamination and peeling when subjected to puncture impact. The dynamic cross-linking network maintains the structural integrity during repeated deformation and improves the puncture resistance, thereby prolonging the service life of the car wrap. Fluorosilane coupling agent endows the coating with low surface energy and chemical stability through fluorocarbon chains, and the silane oxy groups cross-link with the substrate and resin, enhancing the dispersion of nanoparticles and the adhesion of the coating, and improving the optical structure stability. The components cooperate with each other and act synergistically to improve the optical dazzling effect, tensile properties, aging resistance, puncture resistance and self-healing properties of the car wrap.

[0007] Preferably, the raw materials for preparing the loadable color-changing material porous core-shell structure nanoparticles include porous core-shell structure nanoparticles, photochromic materials and thermosensitive hydrogels.

[0008] The porous core-shell structure nanoparticles serve as carriers. Their nanoscale pores form a light capture-release circulation system with the photochromic material, and realize reversible color change through molecular isomerization under ultraviolet irradiation. At the same time, the volume phase change of the thermosensitive hydrogel regulates the core-shell gap and changes the position of the structural color reflection peak. The two are superimposed to form a dynamic dazzling effect with dual responses to light intensity and temperature. The high specific surface area of the porous core-shell structure enhances the loading amount of the photochromic material. The hydrogen bond network of the thermosensitive hydrogel forms a supramolecular assembly with the photochromic molecules, significantly improving the color stability. The flexible shell layer of the core-shell structure and the elastic network of the thermosensitive hydrogel dissipate stress synergistically, optimizing the mechanical properties of the coating. At the same time, the conjugated structure of the photochromic material absorbs ultraviolet light, inhibits the aging phenomenon, and prolongs the service life of the car wrap.

[0009] Preferably, the porous core-shell structure nanoparticles are prepared by the following steps: Dissolve poly(N-isopropylacrylamide) in a solvent, add sodium dodecyl sulfate, heat and stir, then add ammonium persulfate, raise the temperature and stir to react to obtain a microsphere emulsion; ultrasonically disperse nano-silica in a solvent, adjust the pH to acidic to obtain a silica dispersion; add the microsphere emulsion to the silica dispersion, stir to obtain a mixed system, add tetrabutyl titanate to the mixed system, stir and react, and then centrifuge to obtain composite particles; wash the composite particles and then calcine, cool, grind and sieve to obtain porous core-shell structured nanoparticles.

[0010] The silica core provides rigid support to ensure the stability of structural color. The porous shell layer formed after calcining to remove the template agent has a nano-scale pore size distribution, and its mesoporous structure matches the molecular size of the photochromic material. It stabilizes the molecular conformation through the physical confinement effect and improves the photochromic response speed; the silica core and the titanium dioxide shell layer form a heterojunction interface, which uses the photonic crystal effect to regulate the scattering path of light and generate structural color in the visible spectral range, forming a superposition effect with the chemical color change of the photochromic material to achieve multi-dimensional color changes; the high specific surface area of the porous shell layer promotes the uniform dispersion of the photochromic material, avoids color attenuation caused by aggregation, and at the same time enhances the light absorption efficiency through the nano-scale light trapping effect, thereby improving the color saturation; the porous core-shell structured nanoparticles act synergistically with the thermosensitive hydrogel. After the thermosensitive hydrogel fills the porous structure, the volume phase change caused by temperature change dynamically adjusts the shell layer porosity, changes the position of the structural color reflection peak, and forms a synergistic regulation with the light response of the photochromic material to achieve the dynamic dazzling color effect of light intensity-temperature dual response.

[0011] Preferably, the raw materials for preparing the thermosensitive hydrogel include poly(N-isopropylacrylamide), 3-aminopropyltriethoxysilane, dopamine and a cross-linking agent.

[0012] The thermosensitive volume phase change of poly(N-isopropylacrylamide) can dynamically regulate the porosity of the porous core-shell structure, realize the reversible shift of the structural color reflection peak position, and form a dual regulation with the light response of the photochromic material; the catechol group of dopamine forms a strong interfacial interaction with the hydroxyl groups on the nanoparticle surface, ensuring the stable anchoring of the hydrogel on the surface of the optical layer and maintaining the structural integrity of the color dynamic change; the elastic network constructed by 3-aminopropyltriethoxysilane and the cross-linking agent enhances the mechanical strength of the hydrogel and maintains the stability of the pore structure during repeated deformation to ensure color consistency; the hydrophilic network of the hydrogel assists in adjusting the microenvironment of the optical layer through humidity response and synergistically improves the color display effect.

[0013] Preferably, the mass ratio of the porous core-shell structured nanoparticles, the photochromic material and the thermosensitive hydrogel is 1:0.3:(0.35 - 0.45).

[0014] The porous core-shell structured nanoparticles loaded with the color-changing material prepared according to the above mass ratio have good optical dazzling effects and good stability, can maintain the aesthetics for a long time, inhibit the aging phenomenon, and extend the service life of the car wrap.

[0015] In a second aspect, the present application provides a protective layer using a coating with optical dazzling effects, adopting the following technical solution: A protective layer using a coating with optical dazzling effects, the protective layer includes a fluorocarbon hydrophobic protection layer, a self-healing layer, and an optical dazzling layer arranged in sequence. The optical dazzling layer is prepared by coating a coating with optical dazzling effects, and the self-healing layer is prepared by coating a self-healing coating. The preparation raw materials of the self-healing coating include 40-60 parts of polyurethane prepolymer, 20-30 parts of polyamide-amine, 4-8 parts of 1,4-butanedithiol, 2-5 parts of trimethylolpropane, 2-6 parts of nano-aluminum oxide, 1-3 parts of light stabilizer, 0.3-0.5 parts of catalyst, 3-5 parts of plasticizer, and 10-20 parts of solvent.

[0016] The polyurethane prepolymer and polyamide-amine form an interpenetrating dynamic network, in which the isocyanate group of the polyurethane and the amino group of the polyamide-amine form reversible hydrogen bonds and dynamic disulfide bonds under the action of 1,4-butanedithiol, and molecular chain recombination is achieved through thermal activation at the scratch, significantly improving the repair efficiency; trimethylolpropane, as a multi-functional cross-linking agent, reacts with the polyurethane prepolymer to form a three-dimensional network structure, and synergistically with the rigid particle strengthening effect of nano-aluminum oxide, significantly improving the tensile strength and puncture resistance of the coating; the high specific surface area of nano-aluminum oxide adsorbs free radicals and reflects ultraviolet rays, forming a double protection barrier with the light stabilizer to inhibit the photo-oxidative degradation of the coating; the dendritic structure of polyamide-amine provides flexible chain segments, and together with the plasticizer, improves the ductility of the coating, relieves the concentration of external stress, and enables the dynamic network to maintain structural integrity during repeated deformation; the self-healing layer and the optical dazzling layer act synergistically. The dynamic network of the self-healing layer and the thermosensitive hydrogel of the optical layer produce complementary deformations during temperature response, jointly maintaining the stability of the overall structure of the car wrap; the light stabilizer of the self-healing layer and the photochromic material of the optical layer form a synergistic anti-aging system. The former absorbs ultraviolet rays to inhibit the generation of free radicals, and the latter dissipates light energy through photoisomerization. The dual mechanisms extend the service life of the car wrap.

[0017] Preferably, the preparation raw materials of the polyurethane prepolymer include hexamethylene diisocyanate and polycarbonate diol.

[0018] The aliphatic hexamethylene segment provides a flexible backbone, forming a microphase-separated structure with the rigid carbonate groups of the polycarbonate diol, endowing the polyurethane with both high elasticity and rigid support; the cyclic carbonate groups of the polycarbonate diol enhance the intermolecular force through hydrogen bonding, improving the chemical resistance and puncture resistance of the coating; the polyurethane prepolymer reacts with the amino groups of the polyamide-amine to form an interpenetrating network, combined with the dynamic disulfide bonds of 1,4-butanedithiol, achieving efficient self-healing through thermal activation at the scratched area; the polar groups of the polyurethane prepolymer form hydrogen bonds with the hydroxyl groups of the thermosensitive hydrogel, enhancing the interlayer adhesion; the rigid segments of the polycarbonate diol form a mechanical match with the nanocore-shell structure of the optical layer, inhibiting the interfacial stress concentration; the aliphatic structure and the conjugated system of the photochromic material form a photo-thermal synergistic barrier, effectively improving the ultraviolet blocking performance and delaying the coating aging.

[0019] Preferably, the fluorocarbon hydrophobic protective layer is obtained by coating a fluorocarbon hydrophobic protective coating, and the raw materials for preparing the fluorocarbon hydrophobic protective coating include 45-55 parts of fluorinated organosilicon-modified acrylate, 12-18 parts of trimethylolpropane triacrylate, 2-4 parts of light stabilizer, 1-2 parts of antioxidant, 3-6 parts of nano-silica, 0.5-1.5 parts of leveling agent, and 0.1-0.3 parts of defoaming agent.

[0020] The fluorinated organosilicon-modified acrylate combines the low surface energy of the fluorocarbon chain and the weather resistance of organosilicon to form a dense hydrophobic barrier, effectively resisting environmental erosion; trimethylolpropane triacrylate, as a multi-functional cross-linking agent, forms a three-dimensional network structure through curing, improving the coating hardness and adhesion; nano-silica is uniformly dispersed to form a nano-reinforcing phase, enhancing the wear resistance and impact resistance; the light stabilizer and antioxidant synergistically inhibit the free radical chain reaction induced by ultraviolet rays, delaying the coating degradation; the functional additives improve the film-forming uniformity and ensure the optical transparency of the coating; the polar groups of the fluorinated organosilicon coating form hydrogen bond anchoring with the polyurethane prepolymer of the self-healing layer, enhancing the interlayer adhesion; the cross-linked network structure and the dynamic network of the self-healing layer form a mechanical match, which can inhibit the interfacial stress concentration; through the interface synergistic optimization, the efficient coupling of the protective performance and the self-healing function is realized.

[0021] Preferably, the raw materials for preparing the fluorinated organosilicon-modified acrylate include dodecafluoroheptyl methacrylate, vinyltrimethoxysilane, and isooctyl acrylate.

[0022] The long fluorocarbon chain contained in dodecafluoroheptyl methacrylate has a low surface energy, enabling the fluorocarbon hydrophobic protective layer to possess excellent hydrophobicity and oleophobicity. It can effectively prevent pollutants such as water, oil stains, and dust from adhering to the surface of the car wrap, facilitating cleaning and maintaining the clean appearance of the car wrap for a long time. At the same time, the fluorocarbon chain has high chemical stability, which can resist the erosion of ultraviolet rays and chemical substances, enhancing the weather resistance and anti-aging ability of the car wrap; the silicon-oxygen bond in vinyltrimethoxysilane endows the material with good flexibility, high and low temperature resistance, and weather resistance. The silyl group can undergo chemical reactions with other components to form a cross-linked structure, enhancing the cohesion of the coating and the adhesion to the self-healing layer, ensuring the tight combination of the protective layer and the self-healing layer, and improving the overall structural stability; isooctyl acrylate provides good flexibility and viscosity, enabling the coating to spread and adhere better during formation, increasing the density and integrity of the coating; the polar groups of the fluorinated organosilicon-modified acrylate can be tightly combined with components such as the polyurethane prepolymer of the self-healing layer through hydrogen bonds or other interactions, enhancing the interfacial bonding force. Its stable chemical structure and good flexibility can adapt to the dynamic repair mechanism of the self-healing layer. When the self-healing layer undergoes a repair process, the protective layer will not hinder its repair action and can also protect the repair area to a certain extent to prevent interference from external factors, thereby achieving the efficient cooperation of the protective performance and the self-healing function and enhancing the overall service performance and lifespan of the car wrap.

[0023] In a third aspect, the present application provides an application of a protective layer, adopting the following technical solution: An application of a protective layer, wherein the protective layer is applied to a color-changing self-healing car wrap.

[0024] Preferably, the color-changing self-healing car wrap includes a protective film, a fluorocarbon hydrophobic protective layer, a self-healing layer, an optical color layer, a TPU substrate layer, an adhesive layer, and a release film arranged in sequence.

[0025] The car wrap prepared above has an optical color effect, can maintain good aesthetics and self-healing performance for a long time, and has good tensile performance, aging resistance, and puncture resistance.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. The porous core-shell structured nanoparticles of the load-responsive color-changing material construct a three-dimensional photonic crystal framework. The porous core-shell structure has nanoscale light-scattering characteristics, which can achieve the regulation of the color of the photochromic material and provide an optical dazzling effect. Its mesoporous structure forms a nanoscale interpenetrating network with silver nanorods, and the tensile strength is improved through the interfacial friction energy dissipation mechanism. The surface plasmon resonance effect of silver nanorods and the conjugated double bonds of acrylic resin form a photo-thermal synergistic barrier, which improves the ultraviolet absorption rate and simultaneously inhibits the degradation of molecular chains caused by free radicals. Glutaraldehyde forms dynamic Schiff base cross-linking bonds with the amino groups in acrylic resin, and can be self-repaired at room temperature through hydrogen bond recombination after breaking at the scratch. Glacial acetic acid adjusts the pH of the system to a weakly acidic environment, promoting the formation of a dense silver oxide antibacterial layer on the surface of silver nanorods, optimizing the dispersion of core-shell particles, and improving the uniformity of the coating with an optical dazzling effect. The flexible shell layer of the core-shell particles and the rigid core layer of silver nanorods form a gradient mechanical structure, which absorbs energy through delamination when subjected to puncture impact. The dynamic cross-linking network maintains the structural integrity during repeated deformation, improving the puncture resistance and thus extending the service life of the car film. The components cooperate with each other and act synergistically to improve the optical dazzling effect, tensile properties, aging resistance and self-repair performance of the car film.

[0027] 2. The porous core-shell structured nanoparticles serve as a carrier. Its nanoscale pores form a light capture-release cycle system with the photochromic material, and reversible color change is achieved through molecular isomerization under ultraviolet irradiation. At the same time, the volume phase change of the thermosensitive hydrogel regulates the core-shell gap and changes the peak position of the structural color reflection. The two effects are superimposed to form a dynamic dazzling effect with dual response to light intensity and temperature. The high specific surface area of the porous core-shell structure enhances the loading amount of the photochromic material. The hydrogen bond network of the thermosensitive hydrogel and the photochromic molecules form a supramolecular assembly, significantly improving the color stability. The flexible shell layer of the core-shell structure and the elastic network of the thermosensitive hydrogel dissipate stress synergistically, optimizing the mechanical properties of the coating. At the same time, the conjugated structure of the photochromic material absorbs ultraviolet light, inhibits the aging phenomenon, and extends the service life of the car film.

[0028] 3. The polyurethane prepolymer and polyamidoamine form an interpenetrating dynamic network. The isocyanate groups of the polyurethane and the amino groups of the polyamidoamine form reversible hydrogen bonds and dynamic disulfide bonds under the action of 1,4-butanedithiol. Molecular chain recombination is achieved through thermal activation at the scratched area, significantly improving the repair efficiency. Trimethylolpropane, as a multi-functional cross-linking agent, reacts with the polyurethane prepolymer to form a three-dimensional network structure, synergistically enhancing the effect of the rigid particles of nano-aluminum oxide, and significantly improving the tensile strength and puncture resistance of the coating. The high specific surface area of nano-aluminum oxide adsorbs free radicals and reflects ultraviolet light, forming a double protection barrier with the light stabilizer to inhibit the photo-oxidative degradation of the coating. The dendritic structure of the polyamidoamine provides flexible chain segments, which cooperate with the plasticizer to improve the ductility of the coating, relieve the external stress concentration, and enable the dynamic network to maintain the structural integrity during repeated deformation. The self-repair layer and the optical color-changing layer act synergistically. The dynamic network of the self-repair layer and the temperature-sensitive hydrogel of the optical layer produce complementary deformations during temperature response, jointly maintaining the stability of the overall structure of the car wrap. The light stabilizer of the self-repair layer and the photochromic material of the optical layer form a synergistic anti-aging system. The former absorbs ultraviolet light to inhibit the generation of free radicals, and the latter dissipates light energy through photoisomerization. The dual mechanisms extend the service life of the car wrap. Brief Description of the Drawings

[0029] Figure 1 It is a cross-sectional view of a color-changing self-repair car wrap in an embodiment of the present application.

[0030] Description of the reference numerals: 1, protective film; 2, fluorocarbon hydrophobic protective layer; 3, self-repair layer; 4, optical color-changing layer; 5, TPU substrate layer; 6, adhesive layer; 7, release film. Detailed Description of the Embodiments

[0031] The embodiments of the present application disclose a coating with an optical color-changing effect and a protective layer and an application using the coating. The raw materials used in the present application can be obtained from commercially available raw materials except as otherwise specified. The following further details the present application in conjunction with the embodiments: Raw material description: Poly(N-isopropylacrylamide) (CAS No.: 25189-55-3), with a molecular weight of 80,000, Sodium dodecyl sulfate (CAS No.: 151-21-3), Ammonium persulfate (CAS No.: 7727-54-0), Nano-silica (CAS No.: 7631-86-9), with a particle size of 75 nm, Tetrabutyl titanate (CAS No.: 5593-70-4), 3-Aminopropyltriethoxysilane (CAS No.: 919-30-2), The crosslinking agent is N,N'-Methylenebisacrylamide (CAS No.: 110-26-9), Dopamine (CAS No.: 51-61-6), The photochromic material is 1,3,3-Trimethylindolino-6'-nitrobenzopyranospirane (CAS No.: 1498-88-0), The surfactant is Polyethylene glycol octyl phenyl ether (CAS No.: 9002-93-1), The acrylic resin model is Mitsubishi acrylic resin BR-85, Silver nanorods (CAS No.: 7440-22-4), with a diameter of 30 nm and a length of 1 μm, Glutaraldehyde (CAS No.: 111-30-8), Glacial acetic acid (CAS No.: 64-19-7), The fluorocarbon silane coupling agent is Heptadecafluorodecyltrimethoxysilane (CAS No.: 83048-65-1), Hexamethylene diisocyanate (CAS No.: 822-06-0), Polycarbonate diol (CAS No.: 29862-10-0), Polyamide-amine (CAS No.: 163442-68-0), Trimethylolpropane (CAS No.: 77-99-6), The catalyst is Dibutyltin dilaurate (CAS No.: 77-58-7), The light stabilizer is UV-292 (CAS No.: 41556-26-7), The plasticizer is 2,2,4-Trimethyl-1,3-pentanediol diisobutyrate (CAS No.: 25265-77-4), Nano-aluminum oxide (CAS No.: 1344-28-1), with a particle size of 20 nm, 1,4-Butanedithiol (CAS No.: 110-66-7), Dodecafluoroheptyl methacrylate (CAS No.: 134190-79-9), Isooctyl acrylate (CAS No.: 2499-53-4), Vinyltrimethoxysilane (CAS No.: 2768-02-7), 2,2'-Azobis(isobutyronitrile) (CAS No.: 78-67-1), Trimethylolpropane triacrylate (CAS No.: 15625-89-5), The antioxidant is Antioxidant 1010 (CAS No.: 6683-19-8), n-Heptyl methacrylate (CAS No.: 2496-81-3), The materials of the protective film and the release film are PET, and the adhesive layer is acrylic adhesive, with the model of 720, purchased from Suzhou Qinchuan Electric Co., Ltd.

[0032] Example 1 Preparation of porous core-shell structured nanoparticles loaded with color-changing materials Dissolve 11 g of poly(N-isopropylacrylamide) in 400 mL of deionized water, add 1.5 g of sodium dodecyl sulfate as an emulsifier, stir at a speed of 500 rpm at 70 °C for 30 min, add 0.6 g of ammonium persulfate, raise the temperature to 75 °C and stir and react at a speed of 500 rpm for 6 h to obtain a microsphere emulsion; ultrasonically disperse 75 g of nano-silica in 1.5 L of an ethanol aqueous solution with a volume concentration of 75%, add 0.1 mol / L hydrochloric acid to adjust the pH to 2.5 to obtain a silica dispersion; add the microsphere emulsion to the silica dispersion, stir and mix at a speed of 300 rpm for 10 min to obtain a mixed system, dropwise add 100 mL of tetrabutyl titanate to the mixed system, add it all within 30 min, stir and react at a speed of 300 rpm for 4 h, centrifuge to obtain composite particles, wash with deionized water, then raise the temperature to 500 °C at a speed of 5 °C / min and calcine for 2 h, wait until it cools to below 30 °C, then grind and pass through a 100-mesh sieve to obtain porous core-shell structured nanoparticles.

[0033] Preparation of thermosensitive hydrogel Disperse 45.5 g of poly(N-isopropylacrylamide) and 2.5 g of 3-aminopropyltriethoxysilane in 500 mL of deionized water, stir and raise the temperature to 60 °C at a speed of 300 rpm to obtain a mixed solution; add 1.5 g of dopamine and 1 g of N,N'-methylenebisacrylamide to the mixed solution, increase the stirring speed to 400 rpm, under nitrogen protection, raise the temperature to 70 °C and react for 3 h, after the reaction is completed, dialyze and freeze-dry at -20 °C to obtain a thermosensitive hydrogel.

[0034] Preparation of porous core-shell structured nanoparticles loaded with color-changing materials Take 60.61 g of porous core-shell structured nanoparticles and disperse them in 500 mL of absolute ethanol, and obtain a dispersion after ultrasonic treatment; add 18.18 g of a photochromic material to the dispersion, stir and react at 40 °C at a speed of 300 rpm for 2 h, add 21.21 g of a thermosensitive hydrogel, raise the temperature to 50 °C, and stir and react at a speed of 400 rpm for 3 h, after the reaction is completed, centrifuge and discard the supernatant, wash the precipitate with absolute ethanol, and vacuum-dry the washed precipitate at 40 °C to obtain porous core-shell structured nanoparticles loaded with color-changing materials.

[0035] Preparation of a coating with an optical dazzling effect Disperse 1 g of surfactant and 15 g of acrylic resin into 30 g of ethyl acetate, stir at a speed of 300 rpm for 15 min, add 0.5 g of fluorocarbon silane coupling agent, stir at a speed of 300 rpm for 10 min, add 45 g of porous core-shell structured nanoparticles loaded with color-changing materials and 8 g of silver nanorods, ultrasonicate for 30 min, stir at a speed of 600 rpm for 45 min, add 0.5 g of glutaraldehyde and 0.1 g of glacial acetic acid, stir at a speed of 200 rpm for 20 min, perform vacuum degassing and then pass through a 100-mesh sieve to obtain a coating with an optical dazzling effect.

[0036] Preparation of self-healing coating Heat 45 g of hexamethylene diisocyanate to 70 °C, and dropwise add 55 g of polycarbonate diol under the condition of a stirring speed of 200 rpm. Finish the dropwise addition within 1 h. After the dropwise addition is completed, raise the temperature to 80 °C and react for 2 h. After cooling to below 30 °C, obtain a polyurethane prepolymer.

[0037] Mix 40 g of polyurethane prepolymer, 20 g of polyamide-amine and 2 g of trimethylolpropane, add 0.3 g of dibutyltin dilaurate, stir and react at 70 °C at a speed of 200 rpm for 30 min. Sequentially add 1 g of light stabilizer, 3 g of plasticizer and 10 g of butyl acetate, stir at a speed of 300 rpm, then add 2 g of nano-aluminum oxide and 4 g of 1,4-butanedithiol, ultrasonicate for 30 min, perform vacuum degassing, and then pass through a 100-mesh sieve to obtain a self-healing coating.

[0038] Preparation of fluorocarbon hydrophobic protective coating Mix 30 g of dodecafluoroheptyl methacrylate and 20 g of isooctyl acrylate, heat to 80 °C and stir at a speed of 200 rpm until evenly mixed to obtain a monomer mixture; dissolve 5 g of vinyltrimethoxysilane and 0.3 g of azobisisobutyronitrile in 10 g of toluene, add it to the monomer mixture within 1.5 h, maintain the reaction temperature at 80 °C during the addition process, stir at a speed of 200 rpm. After the addition is completed, keep the temperature for reaction for 3 h. After cooling to below 30 °C, perform rotary evaporation to obtain a fluorinated organosilicon acrylate copolymer.

[0039] Mix 45 g of fluorinated organosilicon-modified acrylate and 12 g of trimethylolpropane triacrylate, stir at a speed of 300 rpm for 5 min, add 2 g of light stabilizer and 1 g of antioxidant, stir at a speed of 300 rpm for 10 min. Add 3 g of nano-silica in 3 portions at intervals of 5 min, increase the stirring speed to 600 rpm, disperse for 30 min, sequentially add 0.5 g of leveling agent and 0.1 g of defoaming agent, stir at a speed of 200 rpm for 20 min, and pass through a 100-mesh sieve to obtain a fluorocarbon hydrophobic protective coating.

[0040] Example 2 Preparation of Porous Core-Shell Structure Nanoparticles Loaded with Color-Changing Materials Dissolve 11 g of poly(N-isopropylacrylamide) in 400 mL of deionized water, add 1.5 g of sodium dodecyl sulfate as an emulsifier, stir at a speed of 500 rpm at 70 °C for 30 min, add 0.6 g of ammonium persulfate, raise the temperature to 75 °C and stir and react at a speed of 500 rpm for 6 h to obtain a microsphere emulsion; ultrasonically disperse 75 g of nano-silica in 1.5 L of an ethanol aqueous solution with a volume concentration of 75%, add 0.1 mol / L hydrochloric acid to adjust the pH to 2.5 to obtain a silica dispersion; add the microsphere emulsion to the silica dispersion, stir and mix at a speed of 300 rpm for 10 min to obtain a mixed system, dropwise add 100 mL of tetrabutyl titanate to the mixed system, add it all within 30 min, stir and react at a speed of 300 rpm for 4 h, centrifuge to obtain composite particles, wash with deionized water, then raise the temperature to 500 °C at a speed of 5 °C / min and calcine for 2 h. After cooling to below 30 °C, grind and pass through a 100-mesh sieve to obtain porous core-shell structure nanoparticles.

[0041] Preparation of Thermosensitive Hydrogel Disperse 45.5 g of poly(N-isopropylacrylamide) and 2.5 g of 3-aminopropyltriethoxysilane in 500 mL of deionized water, stir and raise the temperature to 60 °C at a speed of 300 rpm to obtain a mixed solution; add 1.5 g of dopamine and 1 g of N,N'-methylenebisacrylamide to the mixed solution, increase the stirring speed to 400 rpm, under nitrogen protection, raise the temperature to 70 °C and react for 3 h. After the reaction is completed, dialyze and freeze-dry at -20 °C to obtain a thermosensitive hydrogel.

[0042] Preparation of Porous Core-Shell Structure Nanoparticles Loaded with Color-Changing Materials Take 57.14 g of porous core-shell structure nanoparticles and disperse them in 500 mL of absolute ethanol, and obtain a dispersion after ultrasonic treatment; add 17.14 g of photochromic material to the dispersion, stir and react at 40 °C at a speed of 300 rpm for 2 h, add 25.72 g of thermosensitive hydrogel, raise the temperature to 50 °C, and stir and react at a speed of 400 rpm for 3 h. After the reaction is completed, centrifuge and discard the supernatant, wash the precipitate with absolute ethanol, and vacuum-dry the washed precipitate at 40 °C to obtain porous core-shell structure nanoparticles loaded with color-changing materials.

[0043] Preparation of Coating with Optical Colorful Effect Disperse 2 g of surfactant and 20 g of acrylic resin into 40 g of ethyl acetate, stir at a speed of 300 rpm for 15 min, add 0.5 g of fluorocarbon silane coupling agent, stir at a speed of 300 rpm for 10 min, add 55 g of porous core-shell structure nanoparticles loaded with color-changing materials and 12 g of silver nanorods, sonicate for 30 min, stir at a speed of 600 rpm for 45 min, add 1 g of glutaraldehyde and 0.3 g of glacial acetic acid, stir at a speed of 200 rpm for 20 min, perform vacuum degassing and then pass through a 100-mesh sieve to obtain a coating with an optical dazzling effect.

[0044] Preparation of self-healing coating Heat 45 g of hexamethylene diisocyanate to 70 °C, and under the condition of a stirring speed of 200 rpm, dropwise add 55 g of polycarbonate diol, complete the dropwise addition within 1 h. After the dropwise addition is completed, raise the temperature to 80 °C and react for 2 h. After cooling to below 30 °C, obtain a polyurethane prepolymer.

[0045] Mix 60 g of polyurethane prepolymer, 30 g of polyamide-amine and 5 g of trimethylolpropane, add 0.5 g of dibutyltin dilaurate, stir and react at 70 °C at a speed of 200 rpm for 30 min. Add 3 g of light stabilizer, 5 g of plasticizer and 20 g of butyl acetate in sequence, stir at a speed of 300 rpm, then add 6 g of nano-aluminum oxide and 8 g of 1,4-butanedithiol, sonicate for 30 min, perform vacuum degassing, and then pass through a 100-mesh sieve to obtain a self-healing coating.

[0046] Preparation of fluorocarbon hydrophobic protective coating Mix 30 g of dodecafluoroheptyl methacrylate and 20 g of isooctyl acrylate, raise the temperature to 80 °C and stir at a speed of 200 rpm until evenly mixed to obtain a monomer mixture; dissolve 5 g of vinyltrimethoxysilane and 0.3 g of azobisisobutyronitrile in 10 g of toluene, add it to the monomer mixture within 1.5 h, maintain the reaction temperature at 80 °C during the addition process, stir at a speed of 200 rpm. After the addition is completed, keep the temperature for reaction for 3 h. After cooling to below 30 °C, perform rotary evaporation to obtain a fluorinated organosilicon acrylate copolymer.

[0047] Mix 55 g of fluorinated organosilicon-modified acrylate and 18 g of trimethylolpropane triacrylate, stir at a speed of 300 rpm for 5 min, add 4 g of light stabilizer and 2 g of antioxidant, stir at a speed of 300 rpm for 10 min. Add 6 g of nano-silica in 3 portions at intervals of 5 min, increase the stirring speed to 600 rpm, disperse for 30 min, add 1.5 g of leveling agent and 0.3 g of defoaming agent in sequence, stir at a speed of 200 rpm for 20 min, and pass through a 100-mesh sieve to obtain a fluorocarbon hydrophobic protective coating.

[0048] Preparation of protective layer The protective layer includes a fluorocarbon hydrophobic protective layer, a self-healing layer, and an optical color-changing layer arranged in sequence. A coating with an optical color-changing effect is coated on the surface of the substrate to obtain the optical color-changing layer; a self-healing coating is coated on the surface of the optical color-changing layer, and after curing, the self-healing layer is obtained; a fluorocarbon hydrophobic protective coating is coated on the surface of the self-healing layer to obtain the fluorocarbon hydrophobic protective layer.

[0049] Preparation of Color-Changing Self-Healing Car Film The color-changing self-healing car film includes a protective film, a protective layer, a TPU substrate layer, an adhesive layer, and a release film arranged in sequence. The protective layer includes a fluorocarbon hydrophobic protective layer, a self-healing layer, and an optical color-changing layer.

[0050] Example 3 Preparation of Porous Core-Shell Structure Nanoparticles Loaded with Color-Changing Materials Dissolve 11 g of poly(N-isopropylacrylamide) in 400 mL of deionized water, add 1.5 g of sodium dodecyl sulfate as an emulsifier, stir at a speed of 500 rpm at 70 °C for 30 min, add 0.6 g of ammonium persulfate, raise the temperature to 75 °C, and stir and react at a speed of 500 rpm for 6 h to obtain a microsphere emulsion; ultrasonically disperse 75 g of nano-silica in 1.5 L of an ethanol aqueous solution with a volume concentration of 75%, add 0.1 mol / L hydrochloric acid to adjust the pH to 2.5 to obtain a silica dispersion; add the microsphere emulsion to the silica dispersion, stir and mix at a speed of 300 rpm for 10 min to obtain a mixed system, drop 100 mL of tetrabutyl titanate into the mixed system, add it dropwise within 30 min, stir and react at a speed of 300 rpm for 4 h, centrifuge to obtain composite particles, wash with deionized water, then heat up to 500 °C at a speed of 5 °C / min and calcine for 2 h, wait until it cools below 30 °C, grind, and pass through a 100-mesh sieve to obtain porous core-shell structure nanoparticles.

[0051] Preparation of Thermosensitive Hydrogel Disperse 45.5 g of poly(N-isopropylacrylamide) and 2.5 g of 3-aminopropyltriethoxysilane in 500 mL of deionized water, stir and heat up to 60 °C at a speed of 300 rpm to obtain a mixed solution; add 1.5 g of dopamine and 1 g of N,N'-methylenebisacrylamide to the mixed solution, increase the stirring speed to 400 rpm, under nitrogen protection, heat up to 70 °C and react for 3 h. After the reaction, dialyze and freeze-dry at -20 °C to obtain a thermosensitive hydrogel.

[0052] Preparation of Porous Core-Shell Structure Nanoparticles Loaded with Color-Changing Materials Disperse 58.82 g of porous core-shell structured nanoparticles in 500 mL of absolute ethanol, and obtain a dispersion after ultrasonic treatment; add 17.65 g of photochromic material to the dispersion, stir and react at 40 °C at a speed of 300 rpm for 2 h, add 23.53 g of thermosensitive hydrogel, raise the temperature to 50 °C, and stir and react at a speed of 400 rpm for 3 h. After the reaction is completed, centrifuge and discard the supernatant, wash the precipitate with absolute ethanol, and vacuum dry the washed precipitate at 40 °C to obtain porous core-shell structured nanoparticles loaded with a color-changing material.

[0053] Prepare a coating with an optical dazzling effect Disperse 1.5 g of surfactant and 17.5 g of acrylic resin in 35 g of ethyl acetate, stir at a speed of 300 rpm for 15 min, add 0.5 g of fluorocarbon silane coupling agent, stir at a speed of 300 rpm for 10 min, add 50 g of porous core-shell structured nanoparticles loaded with a color-changing material and 10 g of silver nanorods, ultrasonically treat for 30 min, stir at a speed of 600 rpm for 45 min, add 0.75 g of glutaraldehyde and 0.2 g of glacial acetic acid, stir at a speed of 200 rpm for 20 min, perform vacuum degassing and then pass through a 100-mesh sieve to obtain a coating with an optical dazzling effect.

[0054] Prepare a self-healing coating Heat 45 g of hexamethylene diisocyanate to 70 °C, and dropwise add 55 g of polycarbonate diol under the condition of a stirring speed of 200 rpm. Finish the dropwise addition within 1 h. After the dropwise addition is completed, raise the temperature to 80 °C and react for 2 h. After cooling to below 30 °C, obtain a polyurethane prepolymer.

[0055] Mix 50 g of polyurethane prepolymer, 25 g of polyamide-amine and 3.5 g of trimethylolpropane, add 0.4 g of dibutyltin dilaurate, stir and react at 70 °C at a speed of 200 rpm for 30 min, successively add 2 g of light stabilizer, 4 g of plasticizer and 15 g of butyl acetate, stir at a speed of 300 rpm, then add 4 g of nano-aluminum oxide and 6 g of 1,4-butanedithiol, ultrasonically treat for 30 min, perform vacuum degassing and then pass through a 100-mesh sieve to obtain a self-healing coating.

[0056] Prepare a fluorocarbon hydrophobic protective coating Mix 30 g of dodecafluoroheptyl methacrylate and 20 g of isooctyl acrylate, raise the temperature to 80 °C and stir at a speed of 200 rpm until evenly mixed to obtain a monomer mixture; dissolve 5 g of vinyltrimethoxysilane and 0.3 g of azobisisobutyronitrile in 10 g of toluene, add it to the monomer mixture within 1.5 h, maintain the reaction temperature at 80 °C during the addition process and stir at a speed of 200 rpm. After the addition is completed, keep the temperature for reaction for 3 h. After cooling to below 30 °C, perform rotary evaporation to obtain a fluorinated organosilicon acrylate copolymer.

[0057] Mix 50 g of fluorinated organosilicon-modified acrylate and 15 g of trimethylolpropane triacrylate, stir at a speed of 300 rpm for 5 min, add 3 g of light stabilizer and 1.5 g of antioxidant, stir at a speed of 300 rpm for 10 min, add 4.5 g of nano-silica in 3 portions with an interval of 5 min between each addition, increase the stirring speed to 600 rpm, disperse for 30 min, sequentially add 1 g of leveling agent and 0.2 g of defoaming agent, stir at a speed of 200 rpm for 20 min, and pass through a 100-mesh sieve to obtain a fluorocarbon hydrophobic protective coating.

[0058] Prepare the protective layer The protective layer includes a fluorocarbon hydrophobic protective layer, a self-healing layer, and an optical color-changing layer arranged in sequence. Coat a coating with an optical color-changing effect on the surface of the substrate to obtain the optical color-changing layer; coat a self-healing coating on the surface of the optical color-changing layer and cure to obtain the self-healing layer; coat a fluorocarbon hydrophobic protective coating on the surface of the self-healing layer to obtain the fluorocarbon hydrophobic protective layer.

[0059] Prepare the color-changing self-healing car film The color-changing self-healing car film includes a protective film, a protective layer, a TPU substrate layer, an adhesive layer, and a release film arranged in sequence. The protective layer includes a fluorocarbon hydrophobic protective layer, a self-healing layer, and an optical color-changing layer.

[0060] Example 4 Example 4 is based on Example 3. The difference between Example 4 and Example 3 is only that the dosage of the porous core-shell structure nanoparticles in Example 4 is 64.52 g, the dosage of the photochromic material is 19.35 g, and the dosage of the thermosensitive hydrogel is 16.13 g.

[0061] Example 5 Example 5 is based on Example 3. The difference between Example 5 and Example 3 is only that the dosage of the porous core-shell structure nanoparticles in Example 5 is 54.05 g, the dosage of the photochromic material is 16.22 g, and the dosage of the thermosensitive hydrogel is 29.73 g.

[0062] Example 6 Example 6 is based on Example 3. The difference between Example 6 and Example 3 is only that no thermosensitive hydrogel is added when preparing the porous core-shell structure nanoparticles loaded with the color-changing material.

[0063] Example 7 Example 7 is based on Example 3. The difference between Example 7 and Example 3 is only that no polyamide-amine is added when preparing the self-healing coating.

[0064] Example 8 Example 8 is based on Example 3. The only difference between Example 8 and Example 3 is that 1,4-butanedithiol is not added when preparing the self-healing coating in Example 8.

[0065] Example 9 Example 9 is based on Example 3. The only difference between Example 9 and Example 3 is that n-heptyl methacrylate is used to replace dodecafluoroheptyl methacrylate when preparing the fluorinated organosilicon-modified acrylate in Example 9.

[0066] Comparative Example 1 Comparative Example 1 is based on Example 3. The only difference between Comparative Example 1 and Example 3 is that the porous core-shell structured nanoparticles loaded with the color-changing material are replaced by a mixture composed of nano-silica and the photochromic material with a mass ratio of 3:1 in Comparative Example 1.

[0067] Performance detection test (1) Tensile property and aging resistance property test: Select "GB / T 1040.1-2018 Plastics - Determination of tensile properties - Part 1: General principles" and "GB / T 1865-2009 Paints and varnishes - Artificial weathering and exposure to artificial radiation (filtered xenon-arc radiation)" as the standards, test the tensile strength of the specimens before and after aging. Prepare three samples for each specimen, and take the average value after measurement. The test results are recorded in Table 1.

[0068] (2) Self-healing property test: At 60 °C, use a nano-scratch tester to scratch a 5-μm deep scratch on the specimen, record the time required for recovery. Test each specimen three times, and take the average value after measurement. The results are recorded in Table 1.

[0069] (3) Anti-puncture property test: Select "QC / T1171-2022 Automotive paint protection film" as the standard, test the anti-puncture property of the specimens. Test each specimen three times, and take the average value after measurement. The results are recorded in Table 1.

[0070] (4) Optical color-changing effect evaluation test: Select 10 scorers with normal vision, observe the appearance of the specimens, score the optical color-changing effect, with a full score of 10 points. After removing one highest score and one lowest score, take the average value. The results are recorded in Table 1.

[0071] Table 1 Detection results of the tensile property, aging resistance property, self-healing property, anti-puncture property and appearance of the car wrap As can be seen from Table 1, the tensile strength of Examples 1-3 is greater than 24.74 MPa, the tensile strength after aging is greater than 20.15 MPa, the self-healing time is less than 8.6 s, the puncture resistance is greater than 225 N, and the score of the colorful effect is greater than 9.38 points. It can be seen that the color-changing self-healing car film with an optical colorful effect prepared by this application has good tensile properties, aging resistance, self-healing properties and puncture resistance, and excellent optical colorful effects.

[0072] As can be seen from Table 1, the differences between Examples 4, 5, 6 and Example 3 are only as follows: in Example 4, the mass ratio of the porous core-shell structure nanoparticles, the photochromic material and the thermosensitive hydrogel is 1:0.3:0.25; in Example 5, the mass ratio of the porous core-shell structure nanoparticles, the photochromic material and the thermosensitive hydrogel is 1:0.3:0.55; in Example 6, no thermosensitive hydrogel is added when preparing the porous core-shell structure nanoparticles loaded with the color-changing material. Compared with Example 3, the performance of Examples 4, 5, 6 has decreased. This is because after destroying the optimal ratio, the synergistic effect between the three components is affected, the performance is affected, and the optical colorful effect decreases. If the thermosensitive hydrogel is not added, the synergistic effect will be further affected, the optical colorful effect will decrease, the ability to dissipate stress will become worse, and aging is more likely to occur.

[0073] As can be seen from Table 1, the differences between Examples 7, 8 and Example 3 are only as follows: in Example 7, no polyamidoamine is added when preparing the self-healing coating; in Example 8, no 1,4-butanedithiol is added when preparing the self-healing coating. Compared with Example 3, the performance of Examples 7, 8 has decreased. This is because the stability of the crosslinked network will be affected by not adding polyamidoamine or 1,4-butanediol. The reduction of the dynamic crosslinked bonds will affect the self-healing performance, and the stability of the material will decrease, resulting in a decrease in performance.

[0074] As can be seen from Table 1, the difference between Example 9 and Example 3 is only as follows: in Example 9, dodecafluoroheptyl methacrylate is replaced by n-heptyl methacrylate when preparing the fluorinated organosilicon-modified acrylate. Compared with Example 3, the performance of Example 9 has decreased. This is because when the fluorinated acrylate is replaced by acrylate, the introduction of fluorine-containing groups is lacking, the surface energy increases, and the aging resistance decreases. As can be seen from Table 1, the difference between Comparative Example 1 and Example 3 is only as follows: in Comparative Example 1, the porous core-shell structure nanoparticles loaded with the color-changing material are replaced by a mixture of nano-silica and a photochromic material with a mass ratio of 3:1. Compared with Example 3, the performance of Comparative Example 1 has decreased significantly. This is because replacing the porous core-shell structure nanoparticles loaded with the color-changing material with ordinary fillers and photochromic materials results in a decrease in dispersibility, a lack of the nano-light reflection characteristics of the core-shell structure, a decrease in the synergistic effect, and a significant decrease in the optical colorful effect. At the same time, the mechanical gradient structure of the components in the material is also affected, so the puncture resistance of the car film also decreases.

[0075] This specific embodiment is only an interpretation of the present application and does not limit the present application. Through the above description, relevant staff can make various changes and modifications completely within the scope without departing from the technical idea of this application. The technical scope of this application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A paint with an optical dazzling effect, characterized in that: The preparation raw materials include the following components in parts by mass: 45 - 55 parts of porous core - shell structure nanoparticles loaded with color - changing materials 8 - 12 parts of silver nanorods 15 - 20 parts of acrylic resin 1 - 2 parts of surfactant 0.5 - 1 part of glutaraldehyde 0.1 - 0.3 part of glacial acetic acid 0.5 - 1.5 parts of fluorocarbon silane coupling agent 30 - 40 parts of solvent 2. The coating with an optical dazzling effect according to claim 1, characterized in that: The preparation raw materials of the porous core - shell structure nanoparticles loaded with color - changing materials include porous core - shell structure nanoparticles, photochromic materials and thermosensitive hydrogels.

3. The coating with an optical color-changing effect according to claim 2, characterized in that: The porous core - shell structure nanoparticles are prepared by the following steps: Dissolve poly(N - isopropylacrylamide) in a solvent, add sodium dodecyl sulfate, heat and stir, then add ammonium persulfate, raise the temperature and stir for reaction to obtain a microsphere emulsion; ultrasonically disperse nano - silica in a solvent, adjust the pH to acidic to obtain a silica dispersion; add the microsphere emulsion to the silica dispersion, stir to obtain a mixed system, add tetrabutyl titanate to the mixed system, stir and react, then centrifuge to obtain composite particles; wash the composite particles and then calcine, cool, grind and sieve to obtain porous core - shell structure nanoparticles.

4. The paint with an optical color-changing effect according to claim 3, characterized in that: The preparation raw materials of the thermosensitive hydrogel include poly(N - isopropylacrylamide), 3 - aminopropyltriethoxysilane, dopamine and a cross - linker.

5. The coating with an optical color-changing effect according to claim 4, characterized in that: The mass ratio of the porous core - shell structure nanoparticles, photochromic materials and thermosensitive hydrogels is 1:0.3:(0.35 - 0.45).

6. A protective layer applying a coating with an optical dazzling effect as described in any one of claims 1-5, characterized in that: The protective layer includes a fluorocarbon hydrophobic protective layer, a self - repairing layer and an optical iridescent layer arranged in sequence. The optical iridescent layer is prepared by coating a coating with an optical iridescent effect, and the self - repairing layer is prepared by coating a self - repairing coating. The preparation raw materials of the self - repairing coating include 40 - 60 parts of polyurethane prepolymer, 20 - 30 parts of polyamide - amine, 4 - 8 parts of 1,4 - butanedithiol, 2 - 5 parts of trimethylolpropane, 2 - 6 parts of nano - alumina, 1 - 3 parts of light stabilizer, 0.3 - 0.5 parts of catalyst, 3 - 5 parts of plasticizer and 10 - 20 parts of solvent.

7. The protective layer according to claim 6, wherein: The preparation raw materials of the polyurethane prepolymer include hexamethylene diisocyanate and polycarbonate diol.

8. The protective layer according to claim 6, characterized in that: The fluorocarbon hydrophobic protective layer is obtained by coating a fluorocarbon hydrophobic protective coating. The preparation raw materials of the fluorocarbon hydrophobic protective coating include 45 - 55 parts of fluorinated organosilicon - modified acrylate, 12 - 18 parts of trimethylolpropane triacrylate, 2 - 4 parts of light stabilizer, 1 - 2 parts of antioxidant, 3 - 6 parts of nano - silica, 0.5 - 1.5 parts of leveling agent and 0.1 - 0.3 parts of defoaming agent.

9. The protective layer according to claim 8, wherein: The preparation raw materials of the fluorinated organosilicon - modified acrylate include dodecafluoroheptyl methacrylate, vinyltrimethoxysilane and isooctyl acrylate.

10. Use of a protective layer according to any one of claims 6-9, characterized in that: The protective layer is applied to the color - changing self - repairing car film.

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