Self-repairing coating for lens and preparation method of self-repairing coating

Abstract

The invention discloses a self-repairing coating for a lens and a preparation method of the self-repairing coating, relates to the technical field of panoramic cameras and vehicle-mounted camera equipment, and aims to prepare a self-repairing, high-light-transmittance and wear-resistant lens self-repairing material by optimizing components and a process. Monomers are subjected to free radical copolymerization under the action of an initiator, and modified hydroxyethyl acrylate is introduced into dynamic crosslinking points through hydrogen bonds, so that the self-repairing performance of the coating is improved, and surface scratches are repaired; a benzotriazole monomer protects the coating from photodegradation, modified SiO2 and modified Al2O3 can improve hardness and wear resistance, a composite cross-linking agent forms a dual cross-linked network, disulfide bond breakage and recombination and siloxane hydrolytic condensation occur under the action of a catalyst, the self-repairing capacity of the coating is improved, and damp-heat aging resistance and water resistance are enhanced. The coating has excellent wear resistance, light transmission and durability, can protect a lens and inhibit scratches, and is particularly suitable for the fields of vehicle-mounted camera equipment, panoramic cameras and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of panoramic cameras and vehicle-mounted camera equipment, and in particular to a self-repairing coating for a lens and a preparation method thereof. Background Art

[0002] As society develops, people's demands for materials are becoming increasingly stringent. In our daily lives, cameras and cars are increasingly indispensable, but conventional lens materials often present challenges, such as fragility and difficulty in repair. Therefore, the development of a durable, self-healing hydrophobic coating for lens applications has become a hot topic of research.

[0003] The development of self-healing coatings faces numerous technical challenges. While current self-healing coatings exhibit excellent self-healing properties and environmental advantages when applied to panoramic cameras and in-vehicle imaging equipment, they still face several shortcomings and limitations. First, the repair efficiency and repeatability of self-healing coatings are limited. Many coatings can only repair minor damage, but the repair effect is suboptimal for larger defects or performance degradation after long-term use. Second, the repair mechanisms of self-healing coatings often rely on external stimuli such as light, heat, and humidity, which can be limited by environmental conditions in practical applications. For example, the repair effectiveness of light-responsive coatings can be significantly reduced on cloudy days or in low-temperature environments. In the automotive sector, while self-healing coatings can reduce scratches and microcracks, their durability and stability in extreme environments require further optimization. Overall, the application of self-healing coatings in panoramic cameras and in-vehicle imaging equipment is still in its developmental stages, requiring further research and improvement in material design, repair mechanisms, and cost control.

[0004] In order to solve the above problems, the present invention provides a self-repairing coating for lenses and a preparation method thereof. The coating has excellent wear resistance, light transmittance and durability, can protect the lens and inhibit scratches, and can be widely used in the field of vehicle-mounted camera equipment or panoramic cameras, and has practical significance and economic value. Summary of the Invention

[0005] The purpose of the present invention is to provide a self-repairing coating for a lens and a preparation method thereof, so as to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for preparing a self-repairing coating for a lens, the steps of the preparation method are as follows: Step S1: Deionized water and sodium lauryl sulfate were mixed, and methyl methacrylate, cyclohexyl methacrylate, butyl acrylate, functional monomers, benzotriazole monomers, and modified Al2O3 were added. The mixture was emulsified at high speed for 15-20 minutes, and ultrasonicated at 40 kHz for 10-15 minutes to obtain a pre-emulsion. The pre-emulsion was divided into two parts, pre-emulsion A and pre-emulsion B, at a volume ratio of 3:7; Step S2: adding an initiator, modified SiO2, and silicone polyether acrylate to pre-emulsion A, heating to 70-75°C, and keeping warm for 50-60 minutes to obtain a seed emulsion; adding pre-emulsion B to the seed emulsion, and keeping warm at 70-80°C for 40-60 minutes to obtain a composite emulsion; Step S3: Cooling the composite emulsion to 40° C., adjusting the pH to 7.0-7.5 with aqueous ammonia, filtering, adding the catalyst and cross-linking agent to the composite emulsion, stirring for 30-40 minutes, and filtering to obtain the self-healing resin; Step S4: Clean the lens, drop the self-repairing resin on the center of the lens, spin-coat it, and let it stand; first dry it in an oven at 75-85°C for 20-30 minutes, and then heat-treat it at 115-125°C for 60-80 minutes; spray a 1% mass concentration of perfluorooctyltriethoxysilane ethanol solution on the cured surface, and heat-treat it at 80°C for 60-70 minutes to obtain a self-repairing coating for the lens.

[0007] More optimally, in step S1, the benzotriazole monomer is 2-(2'-hydroxyphenyl)benzotriazole; the functional monomer is one or a combination of hydroxyethyl acrylate, hydroxypropyl methacrylate, and hydroxypropyl acrylate; The raw material composition of the pre-emulsion is calculated by weight: 60-80 parts of deionized water, 1.0-1.5 parts of sodium lauryl sulfate, 15-20 parts of methyl methacrylate, 2-5 parts of cyclohexyl methacrylate, 15-25 parts of butyl acrylate, 2-4 parts of hydroxyethyl acrylate, 1-2 parts of 2-(2'-hydroxyphenyl)benzotriazole, and 1-3 parts of modified Al2O3.

[0008] More optimally, the hydroxyethyl acrylate is modified hydroxyethyl acrylate: under nitrogen protection, hydroxyethyl acrylate and 2-isocyanate-4[1H]-pyrimidinone are dissolved in anhydrous tetrahydrofuran at a molar ratio of 1:1.05, and 0.1% of the total mass of the reaction system as a dibutyltin dilaurate catalyst is added, stirred and dissolved, heated to 60-70°C, reacted for 6-7h, distilled under reduced pressure, precipitated, and vacuum dried to obtain modified hydroxyethyl acrylate.

[0009] More optimally, in the composite emulsion, the mass ratio of methyl methacrylate, initiator, modified SiO2, and silicone polyether acrylate is (15-20): (0.2-0.3): (1-3): (2-5); the initiator is a mixture of one or more of ammonium persulfate, sodium persulfate, and potassium persulfate; the initiator is a mixture of potassium persulfate and deionized water at a weight ratio of 1:50; More optimally, in the self-healing resin, the mass ratio of methyl methacrylate, crosslinker, and catalyst is (15-20): (4-6): (0.1-0.2); the crosslinker is a mixture of bis(4-hydroxyphenyl) disulfide and tetraethoxysilane in a weight ratio of 1:1.5, and the catalyst is a mixture of triethylamine and cuprous chloride in a weight ratio of 1:0.2; More optimally, the modified SiO2 is prepared by mixing γ-(methacryloyloxy)propyltrimethoxysilane coupling agent, deionized water, and ethanol solvent, adjusting the pH to 4-5 with acetic acid, stirring at 40-50°C for 30-40 minutes, adding nano-SiO2, stirring at 60-80°C for 4-6 hours, centrifuging, washing with ethanol, and vacuum drying to obtain modified SiO2; The modified Al2O3 is prepared by mixing a γ-(methacryloyloxy)propyltrimethoxysilane coupling agent, deionized water, and an ethanol solvent, adjusting the pH to 4-5 with acetic acid, stirring at room temperature for 30-40 minutes, adding micronized Al2O3, stirring at 60-80°C for 4-6 hours, centrifuging, washing with ethanol, and vacuum drying to obtain the modified Al2O3; the mass ratio of the modified SiO2 to the modified Al2O3 is 1.5:1.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a self-repairing coating for a lens and a preparation method thereof. By optimizing the composition and process, a lens self-repairing material with high light transmittance, resistance to moisture and heat aging, and wear resistance is prepared.

[0011] The monomers undergo free radical copolymerization under the action of potassium persulfate as an initiator. Deionized water is used as the reaction medium to disperse the emulsion. Sodium lauryl sulfate, an emulsifier, is added to stabilize the emulsion and reduce interfacial tension. Methyl methacrylate provides hardness and transparency, cyclohexyl methacrylate enhances heat resistance, and butyl acrylate improves flexibility. Modified hydroxyethyl acrylate introduces dynamic crosslinking points through hydrogen bonds, improving the coating's room-temperature self-healing properties and repairing surface scratches. Benzotriazole monomers act as UV absorbers, absorbing UV rays through intramolecular proton transfer, protecting the coating from photodegradation and ensuring weather resistance, meeting the requirements of long-term outdoor exposure of lenses. Modified SiO2 and modified Al2O3 can form nanostructures, synergistically improve hardness, wear resistance, and improve hydrophobicity; the introduction of silicone polyether acrylate improves hydrophobicity and stain resistance, which is suitable for lens anti-fouling needs, while improving leveling, reducing coating defects, improving optical uniformity, enhancing coating flexibility, and avoiding brittleness caused by high cross-linking degree; a composite cross-linking agent is selected to form a double cross-linked network. Under the action of the catalyst, bis(4-hydroxyphenyl) disulfide and tetraethoxysilane undergo disulfide bond cleavage and recombination and siloxane hydrolysis and condensation reactions. The disulfide bond improves the efficient self-repairing ability of the coating, and the Si-O-Si network formed by hydrolysis enhances the resistance to moisture and heat aging and enhances the water resistance of the coating. During the lens coating and curing steps, the volatile solvent is pre-cured to initially trigger the dynamic cross-linking of disulfide bonds, and then the main curing is carried out to trigger the deep cross-linking of the siloxane network Si-O-Si to repair daily scratches and resist acid rain and ultraviolet rays; 1% mass concentration of perfluorooctyltriethoxysilane is sprayed and cured to form a low surface energy hydrophobic layer, which is waterproof and anti-fouling without affecting the transmittance.

[0012] Acrylate resins have high light transmittance, making them suitable for lens applications and possessing excellent optical compatibility. The emulsion polymerized coating is also highly flexible and can automatically repair itself after minor damage by rearranging its internal chemical bonds. This self-repairing function effectively reduces wear and aging, thereby extending its service life. The coating exhibits excellent wear resistance, light transmittance, and durability, protecting lenses and inhibiting scratches. It is widely used in panoramic cameras and automotive camera technology. DETAILED DESCRIPTION

[0013] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0014] Example 1: A method for preparing a self-repairing coating for a lens, the steps of the preparation method are as follows: Step S1: Deionized water and sodium lauryl sulfate were mixed, and methyl methacrylate, cyclohexyl methacrylate, butyl acrylate, 2-(2'-hydroxyphenyl)benzotriazole, hydroxyethyl acrylate, and modified Al2O3 were added. The mixture was emulsified at high speed for 20 minutes, and ultrasonicated at 40 kHz for 15 minutes to obtain a pre-emulsion. The pre-emulsion was divided into two parts, pre-emulsion A and pre-emulsion B, at a volume ratio of 3:7; Step S2: adding an initiator, modified SiO2, and silicone polyether acrylate to pre-emulsion A, heating to 75°C, and keeping warm for 60 minutes to obtain a seed emulsion; adding pre-emulsion B dropwise to the seed emulsion within 2 hours, and keeping warm at 75°C for 50 minutes to obtain a composite emulsion; Step S3: Cooling the composite emulsion to 40° C., adjusting the pH to 7.5 with aqueous ammonia, filtering, adding the catalyst and cross-linking agent to the composite emulsion, stirring for 40 minutes, and filtering to obtain the self-healing resin; Step S4: After the lens is cleaned with isopropyl alcohol and deionized water, a self-healing resin is dropped onto the center of the lens and rotated at 2000 rpm for 30 seconds to form a uniform film with a thickness of 15 μm. The film is allowed to stand for 5 minutes, dried in an 80°C oven for 30 minutes, and then heat-treated at 120°C for 70 minutes. A 1% mass concentration of perfluorooctyltriethoxysilane ethanol solution is sprayed on the surface and heat-treated at 80°C for 60 minutes to obtain a self-healing coating for the lens. In step S1, the raw material composition of the pre-emulsion is as follows: 60 parts of deionized water, 1.2 parts of sodium lauryl sulfate, 18 parts of methyl methacrylate, 2 parts of cyclohexyl methacrylate, 20 parts of butyl acrylate, 3 parts of hydroxyethyl acrylate, 2 parts of 2-(2'-hydroxyphenyl)benzotriazole, and 1 part of modified Al2O3; The hydroxyethyl acrylate is modified hydroxyethyl acrylate: under nitrogen protection, 10g of hydroxyethyl acrylate and 2-isocyanate-4[1H]-pyrimidinone are dissolved in 50mL of anhydrous tetrahydrofuran at a molar ratio of 1:1.05, 66mg of dibutyltin dilaurate catalyst is added, stirred and dissolved, the temperature is raised to 60°C, the reaction is carried out for 6h, and the mixture is distilled under reduced pressure, precipitated with cold ether three times, and dried in vacuo to obtain modified hydroxyethyl acrylate; In the composite emulsion, the mass ratio of methyl methacrylate, initiator, modified SiO2, and silicone polyether acrylate is 18:0.2:1.5:3; the initiator is potassium persulfate and deionized water in a weight ratio of 1:50; In the self-healing resin, the mass ratio of methyl methacrylate, crosslinker, and catalyst is 18:5:0.2; the crosslinker is a compound of bis(4-hydroxyphenyl) disulfide and tetraethoxysilane in a weight ratio of 1:1.5, and the preparation method of the crosslinker is as follows: dissolving 2 parts of bis(4-hydroxyphenyl) disulfide in 6 parts of anhydrous ethanol, stirring at 60°C for 10 minutes, and obtaining product 1; mixing 3 parts of tetraethoxysilane with 0.15 parts of acetic acid, standing at room temperature for 5 minutes, and obtaining product 2, and mixing product 1 and product 2; the catalyst is a compound of triethylamine and cuprous chloride in a weight ratio of 1:0.2, and the preparation method of the catalyst is as follows: dissolving 0.2 parts of triethylamine and 0.04 parts of CuCl in 5 parts of anhydrous ethanol; The modified SiO2 is prepared by mixing 10 g of γ-(methacryloyloxy)propyltrimethoxysilane, 2 ml of deionized water, and 100 ml of ethanol solvent, adjusting the pH to 4.5 with acetic acid, stirring at 50° C. for 30 minutes, adding 100 g of nano-SiO2, stirring at 70° C. for 5 hours, centrifuging, washing with ethanol three times, and vacuum drying at 60° C. to obtain the modified SiO2; The modified Al2O3 is prepared by mixing 5g of γ-(methacryloyloxy)propyltrimethoxysilane, 2ml of deionized water, and 100ml of ethanol solvent, adjusting the pH to 4.5 with acetic acid, stirring at room temperature for 30 minutes, adding 20g of micronized Al2O3, stirring at 70°C for 5 hours, centrifuging, washing three times with ethanol, and vacuum drying at 60°C to obtain the modified Al2O3.

[0015] Example 2: A method for preparing a self-repairing coating for a lens, the steps of the preparation method are as follows: Step S1: Deionized water and sodium lauryl sulfate were mixed, and methyl methacrylate, cyclohexyl methacrylate, butyl acrylate, 2-(2'-hydroxyphenyl)benzotriazole, hydroxyethyl acrylate, and modified Al2O3 were added. The mixture was emulsified at high speed for 15 minutes, and ultrasonicated at 40 kHz for 15 minutes to obtain a pre-emulsion. The pre-emulsion was divided into two parts, pre-emulsion A and pre-emulsion B, at a volume ratio of 3:7; Step S2: adding an initiator, modified SiO2, and silicone polyether acrylate to pre-emulsion A, heating to 70°C, and keeping warm for 50 minutes to obtain a seed emulsion; adding pre-emulsion B dropwise to the seed emulsion 2 hours later, and keeping warm at 75°C for 50 minutes to obtain a composite emulsion; Step S3: Cooling the composite emulsion to 40° C., adjusting the pH to 7.0 with aqueous ammonia, filtering, adding the catalyst and cross-linking agent to the composite emulsion, stirring for 30 minutes, and filtering to obtain the self-healing resin; Step S4: After the lens is cleaned with isopropyl alcohol and deionized water, a self-healing resin is dropped onto the center of the lens and spun at 2000 rpm for 20 seconds to form a uniform film with a thickness of 20 μm. The film is allowed to stand for 10 minutes, dried in an 85°C oven for 30 minutes, and then heat-treated at 115°C for 60 minutes. A 1% mass concentration of perfluorooctyltriethoxysilane ethanol solution is sprayed onto the surface and heat-treated at 80°C for 70 minutes to obtain a self-healing coating for the lens. In step S1, the raw material composition of the pre-emulsion is as follows: 80 parts of deionized water, 1.5 parts of sodium lauryl sulfate, 17 parts of methyl methacrylate, 3 parts of cyclohexyl methacrylate, 24 parts of butyl acrylate, 4 parts of hydroxyethyl acrylate, 2 parts of 2-(2'-hydroxyphenyl)benzotriazole, and 2 parts of modified Al2O3; The hydroxyethyl acrylate is modified hydroxyethyl acrylate: under nitrogen protection, 10g of hydroxyethyl acrylate and 2-isocyanate-4[1H]-pyrimidinone were dissolved in 50mL of anhydrous tetrahydrofuran at a molar ratio of 1:1.05, 66mg of dibutyltin dilaurate catalyst was added, stirred and dissolved, the temperature was raised to 60°C, the reaction was carried out for 6h, and the mixture was distilled under reduced pressure, precipitated with cold ether three times, and dried in vacuo to obtain modified hydroxyethyl acrylate; In the composite emulsion, the mass ratio of methyl methacrylate, initiator, modified SiO2, and silicone polyether acrylate is 17:0.3:3:2; the initiator is potassium persulfate and deionized water in a weight ratio of 1:50; In the self-healing resin, the mass ratio of methyl methacrylate, crosslinker, and catalyst is 17:4:0.2; the crosslinker is a compound of bis(4-hydroxyphenyl) disulfide and tetraethoxysilane in a weight ratio of 1:1.5, and the preparation method of the crosslinker is as follows: 1.5 parts of bis(4-hydroxyphenyl) disulfide are dissolved in 6 parts of anhydrous ethanol, and stirred at 60°C for 10 minutes to obtain product 1; 2.25 parts of tetraethoxysilane are mixed with 0.1 parts of acetic acid, and allowed to stand at room temperature for 5 minutes to obtain product 2, and products 1 and 2 are mixed; the catalyst is a compound of triethylamine and cuprous chloride in a weight ratio of 1:0.2, and the preparation method of the catalyst is as follows: 0.2 parts of triethylamine and 0.04 parts of CuCl are dissolved in 5 parts of anhydrous ethanol; The modified SiO2 is prepared by mixing 10 g of γ-(methacryloyloxy)propyltrimethoxysilane, 2 ml of deionized water, and 100 ml of ethanol solvent, adjusting the pH to 4.5 with acetic acid, stirring at 50° C. for 30 minutes, adding 100 g of nano-SiO2, stirring at 70° C. for 5 hours, centrifuging, washing with ethanol three times, and vacuum drying at 60° C. to obtain the modified SiO2; The modified Al2O3 is prepared by mixing 5g of γ-(methacryloyloxy)propyltrimethoxysilane, 2ml of deionized water, and 100ml of ethanol solvent, adjusting the pH to 4.5 with acetic acid, stirring at room temperature for 30 minutes, adding 20g of micronized Al2O3, stirring at 70°C for 5 hours, centrifuging, washing three times with ethanol, and vacuum drying at 60°C to obtain the modified Al2O3.

[0016] Example 3: A method for preparing a self-repairing coating for a lens, the steps of the preparation method are as follows: Step S1: Deionized water and sodium lauryl sulfate were mixed, and methyl methacrylate, cyclohexyl methacrylate, butyl acrylate, 2-(2'-hydroxyphenyl)benzotriazole, hydroxyethyl acrylate, and modified Al2O3 were added. The mixture was emulsified at high speed for 20 minutes, and ultrasonicated at 40 kHz for 10 minutes to obtain a pre-emulsion. The pre-emulsion was divided into two parts, pre-emulsion A and pre-emulsion B, at a volume ratio of 3:7; Step S2: adding an initiator, modified SiO2, and silicone polyether acrylate to pre-emulsion A, heating to 75°C, and keeping warm for 60 minutes to obtain a seed emulsion; adding pre-emulsion B dropwise to the seed emulsion 2 hours later, and keeping warm at 80°C for 60 minutes to obtain a composite emulsion; Step S3: Cooling the composite emulsion to 40° C., adjusting the pH to 7.5 with aqueous ammonia, filtering, adding the catalyst and cross-linking agent to the composite emulsion, stirring for 30 minutes, and filtering to obtain the self-healing resin; Step S4: After the lens is cleaned with isopropyl alcohol and deionized water, a self-healing resin is dropped onto the center of the lens and rotated at 2500 rpm for 30 seconds to form a uniform film with a thickness of 20 μm. The film is allowed to stand for 5 minutes, dried in an 80°C oven for 20 minutes, and then heat-treated at 115°C for 80 minutes. A 1% mass concentration of perfluorooctyltriethoxysilane ethanol solution is sprayed on the surface and heat-treated at 80°C for 60 minutes to obtain a self-healing coating for the lens. In step S1, the raw material composition of the pre-emulsion is as follows: 70 parts of deionized water, 1.5 parts of sodium lauryl sulfate, 18 parts of methyl methacrylate, 3 parts of cyclohexyl methacrylate, 25 parts of butyl acrylate, 2 parts of hydroxyethyl acrylate, 2 parts of 2-(2'-hydroxyphenyl)benzotriazole, and 1 part of modified Al2O3; The hydroxyethyl acrylate is modified hydroxyethyl acrylate: under nitrogen protection, 10g of hydroxyethyl acrylate and 2-isocyanate-4[1H]-pyrimidinone were dissolved in 50mL of anhydrous tetrahydrofuran at a molar ratio of 1:1.05, 66mg of dibutyltin dilaurate catalyst was added, stirred and dissolved, the temperature was raised to 60°C, the reaction was carried out for 6h, and the mixture was distilled under reduced pressure, precipitated with cold ether three times, and dried in vacuo to obtain modified hydroxyethyl acrylate; In the composite emulsion, the mass ratio of methyl methacrylate, initiator, modified SiO2, and silicone polyether acrylate is 18:0.2:1.5:4; the initiator is potassium persulfate and deionized water in a weight ratio of 1:50; In the self-healing resin, the mass ratio of methyl methacrylate, crosslinker, and catalyst is 18:4:0.2; the crosslinker is a compound of bis(4-hydroxyphenyl) disulfide and tetraethoxysilane in a weight ratio of 1:1.5, and the preparation method of the crosslinker is as follows: dissolving 2 parts of bis(4-hydroxyphenyl) disulfide in 6 parts of anhydrous ethanol, stirring at 60°C for 10 minutes, and obtaining product 1; mixing 3 parts of tetraethoxysilane with 0.15 parts of acetic acid, standing at room temperature for 5 minutes, and obtaining product 2, and mixing product 1 and product 2; the catalyst is a compound of triethylamine and cuprous chloride in a weight ratio of 1:0.2, and the preparation method of the catalyst is as follows: dissolving 0.2 parts of triethylamine and 0.04 parts of CuCl in 5 parts of anhydrous ethanol; The modified SiO2 is prepared by mixing 10 g of γ-(methacryloyloxy)propyltrimethoxysilane, 2 ml of deionized water, and 100 ml of ethanol solvent, adjusting the pH to 4.5 with acetic acid, stirring at 50° C. for 30 minutes, adding 100 g of nano-SiO2, stirring at 70° C. for 5 hours, centrifuging, washing with ethanol three times, and vacuum drying at 60° C. to obtain the modified SiO2; The modified Al2O3 is prepared by mixing 5g of γ-(methacryloyloxy)propyltrimethoxysilane, 2ml of deionized water, and 100ml of ethanol solvent, adjusting the pH to 4.5 with acetic acid, stirring at room temperature for 30 minutes, adding 20g of micronized Al2O3, stirring at 70°C for 5 hours, centrifuging, washing three times with ethanol, and vacuum drying at 60°C to obtain the modified Al2O3.

[0017] Comparative Example 1: Taking Example 1 as the control group, modified hydroxyethyl acrylate was replaced by hydroxyethyl acrylate, and other processes were normal.

[0018] Comparative Example 2: Taking Example 1 as the control group, nano-SiO2 was used to replace the modified SiO2, and the other processes were normal.

[0019] Comparative Example 3: Taking Example 1 as the control group, modified Al2O3 was replaced by micronized Al2O3, and other processes were normal.

[0020] Sources of raw materials used (for demonstration purposes only): The raw materials in this technical solution are all products currently available on the market. Methyl methacrylate (80-62-6, 99.9%): Shandong Jinyueyuan New Materials Co., Ltd.; Cyclohexyl methacrylate (101-43-9, 99%): Changzhou Guxu Chemical Co., Ltd.; 2-(2'-Hydroxyphenyl)benzotriazole (3864-99-1, 99%): Nanjing Chemical Reagent Co., Ltd.; Butyl acrylate (141-32-2, 99.5%): Jinan Aochen Chemical Co., Ltd.; Hydroxyethyl acrylate (818-61-1, 99%): Jinan Aochen Chemical Co., Ltd.; Sodium lauryl sulfate emulsifier (151-21-3, 99%): Shandong Yukang Chemical Co., Ltd.; Potassium persulfate (7727-21-1, 99.5%): Xingtianwai Chemical (Shanghai) Co., Ltd.; Bis(4-hydroxyphenyl) disulfide (13080-96-1, 99%): Hubei Xinrunde Chemical Co., Ltd.; Tetraethoxycaprylylsilane (TET) Silane (78-10-4, 99%): Wuhan Youji Industrial Co., Ltd.; dibutyltin dilaurate (77-58-7, 99.5%): Jinan Century Tongda Chemical Co., Ltd.; perfluorooctyltriethoxysilane (51851-37-7, 98%): Hubei Zhenbo Chemical Co., Ltd.; 2-isocyanate-4[1H]-pyrimidinone (344652-70-8, 98%): Shanghai MacLean Biochemical Technology Co., Ltd.; micronized Al2O3 (5 μm, 1344-28-1, 99.9%): Sinopharm Chemical Reagent Co., Ltd.; nano-SiO2 (20 nm, 7631-86-9, 90%): Xi'an Qiyue Biotechnology Co., Ltd.; cuprous chloride (7758-89-6, 99%): Shandong Yukang Chemical Co., Ltd.; triethylamine, cold ether, tetrahydrofuran, ammonia water, and anhydrous ethanol were all of analytical grade and commercially available.

[0021] Performance test: The self-repairing coatings prepared in the examples and comparative examples were tested: After the self-healing resin was cured in the mold, it was cut into a size of 100 mm × 100 mm × 15 μm as a coating sample.

[0022] Transmittance: Use a UV-Vis spectrophotometer and standard transmittance sheets for baseline correction. Cut the coating sample into 50mm x 50mm dimensions and place it in the test light path. Scan the wavelength from 300-800nm ​​and record the transmittance at 550nm.

[0023] Pencil hardness test: According to GB / T 6739-2022, a 9H-6B series hardness pencil was used to scratch the coating surface at a 45° angle with a load of 750g.

[0024] Adhesion test: A cross-hatch test was conducted according to GB / T 9286-2021. After scratching with a 1mm spacing, 3M tape was used to peel off the coating. The coating shedding in the grid area was observed under a standard light source. The adhesion grade was assessed according to the standard atlas: no grid shedding was rated as grade 0, a peeling area of ​​less than 5% was rated as grade 1, a coating peeling area of ​​less than 15% was rated as grade 2, a peeling area of ​​less than 35% was rated as grade 3, a grid shedding area of ​​less than 65% was rated as grade 4, and a coating peeling of more than 65% was rated as grade 5.

[0025] Self-repair test: Use a blade to create a standard scratch on the coating surface with a width of approximately 10μm. Select at least 3 points at the center and both ends of the scratch, accurately measure and record the initial average width of the scratch (W0). After heating at 80℃ for 2h, use the same microscope to remeasure the average width of the scratch (W1) at the same position. Calculate the self-repair rate (η): η=[(W0-W1) / W0]x100%.

[0026] Moisture and heat aging resistance test: Place the sample in a constant temperature and humidity chamber (temperature 85°C, relative humidity 85% RH), take it out after 1000 hours, and observe the changes in surface morphology. If the glossiness does not decrease and there are no bubbles or damage, it is qualified; otherwise, it is unqualified.

[0027] Abrasion resistance: Taber abrasion resistance testing uses a CS-10 abrasive wheel. Coated samples are cut into circular shapes with a diameter of 100 mm and a central hole. The sample is then mounted on a turntable and loaded with a 500 g weight. The mass loss after 1000 revolutions is recorded. Before testing, the initial sample mass m0 is accurately measured. After testing, the sample is cleaned and free of loose debris, and the final sample mass m1 is accurately measured. The mass loss Δm is calculated as: Δm = m0 - m1 (mg).

[0028] Water contact angle test: Using a Krüss DSA25 contact angle meter, the self-healing coating sample was cut into 20 mm x 20 mm specimens. 2 μL of ultrapure water (resistivity ≥ 18.2 MΩ·cm) was deposited onto the coating surface from a height of 3 mm. After standing for 10 seconds, data was collected. The left and right contact angles were measured and averaged. This was repeated five times, with the median value taken.

[0029] The test results are as follows: Table 1 The analysis results are as follows: The high light transmittance is attributed to the high light transmittance of the acrylic resin itself, which is suitable for lens applications and has good optical adaptability. The spin coating process forms a uniform film, and microscopy verifies that there is no orange peel / shrinkage, reducing light scattering loss. The transmittance at 550nm is 92.1%-93.4%.

[0030] Modified hydroxyethyl acrylate introduces dynamic cross-linking points through hydrogen bonds, improving the room temperature self-healing performance of the coating and repairing surface scratches. Under the action of the catalyst, the cross-linking agent bis(4-hydroxyphenyl) disulfide undergoes disulfide bond rupture and recombination, improving the self-healing ability of the coating, with a self-repair rate of >90%; modified SiO2 and modified Al2O3 can improve hardness and wear resistance, improve hydrophobicity, adhesion level 0, pencil hardness up to 3H, and hydrophobic angle >120°, meeting the anti-fouling requirements of vehicle-mounted camera equipment; after 1000h of moisture and heat resistance testing, the glossiness remains unchanged and there are no bubbles or damage, proving the long-term stability of disulfide bonds and hydrogen bonds. The pencil hardness decreases slightly due to the relaxation of some dynamic bonds due to long-term moisture and heat, but it still meets the standard.

[0031] By comparing Example 1 with Comparative Examples 1, 2, and 3, it can be seen that when hydroxyethyl acrylate (HEA) is used to replace modified hydroxyethyl acrylate (HEA-UPy), the self-repair rate is greatly reduced, and other properties are slightly reduced due to the loss of the dynamic hydrogen bond repair mechanism of the UPy dimer; replacing silane-modified SiO2 with ordinary SiO2 will lead to poor dispersibility and a significant decrease in the light transmittance of the coating from ≥90% to 83.2%, and particle agglomeration may occur, the interfacial bonding strength is weakened, the wear resistance is reduced, and the pencil hardness is reduced; when ordinary Al2O3 is used to replace modified Al2O3, the hardness and adhesion are reduced due to insufficient interfacial bonding strength.

[0032] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A method for preparing a self-repairing coating for a lens, characterized in that: The steps of the preparation method are as follows: Step S1: Deionized water and sodium lauryl sulfate are mixed, and methyl methacrylate, cyclohexyl methacrylate, butyl acrylate, functional monomers, benzotriazole monomers, and modified Al2O3 are added, emulsified, and then ultrasonically treated to obtain a pre-emulsion, which is then divided into two parts, pre-emulsion A and pre-emulsion B, at a volume ratio of 3:7; Step S2: adding an initiator, modified SiO2, and silicone polyether acrylate to pre-emulsion A, heating the pre-emulsion to obtain a seed emulsion, adding pre-emulsion B to the seed emulsion, and heat-insulating the pre-emulsion to obtain a composite emulsion; Step S3: Cooling the composite emulsion, adjusting the pH, filtering, adding a catalyst and a cross-linking agent to the composite emulsion, stirring and filtering, and obtaining a self-healing resin; Step S4: clean the lens, drop the self-repairing resin on the center of the lens, spin-coat it, let it stand, perform gradient temperature treatment, spray the hydrophobic agent on the cured surface, and perform heat treatment to obtain a self-repairing coating for the lens.

2. The method for preparing a self-repairing coating for a lens according to claim 1, wherein: In step S1, the benzotriazole monomer is 2-(2'-hydroxyphenyl)benzotriazole; and the functional monomer is one or a combination of hydroxyethyl acrylate, hydroxypropyl methacrylate, and hydroxypropyl acrylate.

3. The method for preparing a self-repairing coating for a lens according to claim 1, wherein: In step S1, the raw material composition of the pre-emulsion is, in parts by weight, 60-80 parts of deionized water, 1.0-1.5 parts of sodium lauryl sulfate, 15-20 parts of methyl methacrylate, 2-5 parts of cyclohexyl methacrylate, 15-25 parts of butyl acrylate, 2-4 parts of hydroxyethyl acrylate, 1-2 parts of 2-(2'-hydroxyphenyl)benzotriazole, and 1-3 parts of modified Al2O3.

4. The method for preparing a self-repairing coating for a lens according to claim 2, wherein: The hydroxyethyl acrylate is modified hydroxyethyl acrylate. The preparation process of the modified hydroxyethyl acrylate is as follows: under nitrogen protection, hydroxyethyl acrylate and 2-isocyanate-4[1H]-pyrimidinone are dissolved in anhydrous tetrahydrofuran at a molar ratio of 1:1.05, a catalyst is added, stirred and dissolved, the temperature is increased, reduced pressure distillation is performed, precipitation and drying are performed to obtain the modified hydroxyethyl acrylate.

5. The method for preparing a self-repairing coating for a lens according to claim 1, wherein: In the composite emulsion, the mass ratio of methyl methacrylate, initiator, modified SiO2, and silicone polyether acrylate is (15-20): (0.2-0.3): (1-3): (2-5); the initiator is a compound of one or more of ammonium persulfate, sodium persulfate, and potassium persulfate; and the initiator is a compound of potassium persulfate and deionized water in a weight ratio of 1:

50.

6. The method for preparing a self-repairing coating for a lens according to claim 1, wherein: In the self-healing resin, the mass ratio of methyl methacrylate, crosslinker and catalyst is (15-20): (4-6): (0.1-0.2); the catalyst is triethylamine and cuprous chloride in a weight ratio of 1:0.2, and the crosslinker is bis(4-hydroxyphenyl) disulfide and tetraethoxysilane in a weight ratio of 1:1.

5.

7. The method for preparing a self-repairing coating for a lens according to claim 1, wherein: The modified SiO2 is prepared by mixing a coupling agent, deionized water, and an ethanol solvent, adjusting the pH to 4-5 with acetic acid, stirring at 40-50° C. for 30-40 minutes, adding nano-SiO2, stirring at 60-80° C. for 4-6 hours, centrifuging, washing with ethanol, and vacuum drying to obtain the modified SiO2.

8. The method for preparing a self-repairing coating for a lens according to claim 1, wherein: The modified Al2O3 is prepared by mixing a coupling agent, deionized water, and an ethanol solvent, adjusting the pH to 4-5 with acetic acid, stirring at room temperature for 30-40 minutes, adding micronized Al2O3, stirring at 60-80°C for 4-6 hours, centrifuging, washing with ethanol, and vacuum drying to obtain modified Al2O3; the mass ratio of the modified SiO2 to the modified Al2O3 is 1.5:

1.

9. The method for preparing a self-repairing coating for a lens according to claim 1, wherein: In step S4, the gradient temperature treatment process is: first drying in an oven at 75-85°C for 20-30 minutes, and then heat treatment at 115-125°C for 60-80 minutes; the hydrophobic agent is a 1% mass concentration perfluorooctyltriethoxysilane ethanol solution.

10. A self-repairing coating for a lens, characterized by: Prepared according to the preparation method according to any one of claims 1 to 9.

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