A metal surface easy-to-clean clear coating and a method for preparing the same

Abstract

The application relates to the technical field of paint, and discloses a metal surface easy-to-clean transparent paint and a preparation method thereof, which comprises the following raw materials in proportion by weight: modified acrylic ester resin: 5-15 parts by weight; aluminum sol: 5-15 parts by weight; silica sol: 10-20 parts by weight; silane coupling agent: 5-10 parts by weight; and solvent: 20-50 parts by weight. The modified acrylic ester resin is obtained by polymerization of monomer raw materials in the solvent, and the monomer raw materials comprise fluorine-substituted acrylic ester monomers, long-carbon-chain acrylic ester monomers and vinyl siloxane monomers. The metal surface easy-to-clean transparent paint is a transparent solution, can be sprayed on a metal surface, can be rapidly solidified at normal temperature to form an easy-to-clean coating, and has the advantages of excellent hydrophobic and oleophobic properties, excellent adhesion, excellent wear resistance and excellent scratch resistance.

Description

Technical Field

[0001] This application relates to the field of coating technology, and mainly to an easy-to-clean transparent coating for metal surfaces and its preparation method. Background Technology

[0002] Household metal products, including aluminum alloy doors and windows and kitchenware, are frequently exposed to rain and oil, easily leading to dust and grease buildup and requiring frequent cleaning. Furthermore, the surfaces of these metal products are easily scratched or graffitied during use or cleaning, making them difficult to repair and severely affecting their appearance. For easy-to-clean protection of metal surfaces, a hydrophobic and oleophobic coating is typically applied. However, this original coating often loses its effectiveness after prolonged use and exposure to UV rays and cleaning agents. To enable household metal products to quickly regain their easy-to-clean protection, a suitable easy-to-clean coating for home use needs to be developed. This type of easy-to-clean coating must be easy to apply, stable, colorless, transparent, and safe.

[0003] Most reported technologies currently utilize modified polysiloxane resins and acrylate resins as main raw materials to form a low surface energy organic coating on the surface of a metal substrate. To further enhance hydrophobicity, they are often combined with micro / nanostructure technology, adding nanoparticles and micron-sized particles to construct micro / nanostructures. However, these coatings often suffer from low adhesion, and their lifespan is significantly reduced in areas frequently exposed to sunlight, rain, and oil fumes. Furthermore, the micro / nanostructures are very prone to detachment under prolonged cleaning and friction.

[0004] Patent applications CN108676442A and CN108129971A mention a metal surface coating with oil-repellent and scratch-resistant functions, which requires curing at 100℃, making it unsuitable for household settings or metal products in use. Patent applications CN113953166A and CN11442508A, to increase the adhesion between the organic coating and the metal, require the establishment of a silica layer or a bio-polyphenol layer on the metal surface, which also increases the complexity of easy-to-clean coating preparation. Patent application CN108276812A mentions using a silane coupling agent and silica sol to obtain a transparent spray liquid, which has good hydrophobicity, but its anti-graffiti and scratch resistance properties need improvement. Patent application CN121228152A attempts to enhance the oil repellency and adhesion of the coating using fluorinated modified polysiloxane resin and epoxy modified silicone resin, but does not examine its abrasion resistance and scratch resistance. The above patent applications only focus on some functions of easy-to-clean coatings for metal surfaces, and cannot fully meet the multifaceted performance requirements of easy-to-clean coatings for home use.

[0005] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this application is to provide an easy-to-clean transparent coating for metal surfaces and a method for preparing the same, in order to solve the problem that existing easy-to-clean coatings cannot meet the performance requirements for use in home settings.

[0007] The technical solution of this application is as follows: A transparent coating for easy cleaning of metal surfaces, comprising, by weight, the following raw materials: Modified acrylate resin: 5-15 parts by weight; Aluminum sol: 5-15 parts by weight; Silica sol: 10-20 parts by weight; Silane coupling agent: 5-10 parts by weight; Solvent: 34-73.5 parts by weight; The modified acrylate resin is obtained by polymerizing monomer raw materials in the solvent, and the monomer raw materials include fluorinated acrylate monomers, long carbon chain acrylate monomers, and vinylsiloxane monomers.

[0008] The aforementioned easy-to-clean transparent coating for metal surfaces, wherein, by weight, the amount of monomer raw materials used in the easy-to-clean transparent coating for metal surfaces is as follows: The fluorinated acrylate monomer: 1-5 parts by weight; The long-chain acrylate monomer: 1-5 parts by weight; The vinylsiloxane monomer: 1-10 parts by weight; The raw materials for the modified acrylate resin also include an initiator; The amount of initiator added is 1 wt% of the total monomer mass.

[0009] The aforementioned easy-to-clean transparent coating for metal surfaces, wherein the number of carbon atoms in the long-chain acrylate monomer is in the range of 12-18; The fluorinated acrylate monomers have a fluorocarbon chain with 3-6 carbon atoms.

[0010] The aforementioned easy-to-clean transparent coating for metal surfaces, wherein the fluorinated acrylate monomer is one or a mixture of two or more of trifluoroethyl methacrylate, hexafluorobutyl methacrylate, hexafluorobutyl acrylate, and trifluoroethyl methacrylate; The long-chain acrylate monomer is one or a mixture of two or more of dodecyl acrylate, tetradecyl acrylate, hexadecyl acrylate, and octadecyl acrylate; The vinylsiloxane monomers are one or a mixture of two or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, and vinylmethyldiethoxysilane.

[0011] The aforementioned easy-to-clean transparent coating for metal surfaces contains a fluorinated acrylate monomer, a long-chain acrylate monomer, and a vinylsiloxane monomer in a mass ratio of 1:1:1.

[0012] The aforementioned easy-to-clean transparent coating for metal surfaces, wherein the silane coupling agent is one or a mixture of two or more of methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, octyltrimethylsilane, 3-glycidyl etheroxypropyltrimethoxysilane, and 3-glycidyl etheroxypropyltriethoxysilane. The silane coupling agent is used to modify the silica sol and the aluminum sol. The silica sol and the aluminum sol are modified using the same or different silane coupling agents; The mass ratio of the silane coupling agent used to treat the silica sol to the mass of the silica sol is 1:3 to 1:1; The mass ratio of the silane coupling agent used to treat the aluminum sol to the mass of the aluminum sol is 1:5 to 1:1.

[0013] The aforementioned easy-to-clean transparent coating for metal surfaces contains ethanol as the solvent.

[0014] The aforementioned easy-to-clean transparent coating for metal surfaces, by weight, further comprises the following raw materials: Anti-scratch additive: 1-5 parts by weight; Anti-aging agent: 0.5-1 part by weight; The anti-scratch additive is one or a mixture of two or more of polydimethylsiloxane (silicone oil) and its modifiers; The anti-aging agent is one or a mixture of two or more of Irganox® 1010, Hostavin® N30P, Tinuvin® NOR® 600, ADKSTAB AO-60, and HS-770.

[0015] A method for preparing an easy-to-clean transparent coating for metal surfaces as described above, comprising the following steps: An initiator is added to the solvent, nitrogen gas is bubbled through the system, and then the system is heated to reflux. Fluorinated acrylate monomers, long-chain acrylate monomers, and vinylsiloxane monomers are added dropwise at the same time. The reaction is carried out under reflux for 1-2 hours to obtain a modified acrylate resin solution. A silane coupling agent was added to the silica sol, and the mixture was stirred at room temperature for 1 hour to obtain a modified silica sol. A silane coupling agent was added to the aluminum sol, and the mixture was stirred at room temperature for 1 hour to obtain the modified aluminum sol. The modified silica sol and the modified aluminum sol are mixed, and then the modified acrylate resin solution is added. The pH is adjusted to 3-5, and the mixture is stirred at room temperature for 1-2 hours to obtain the easy-to-clean transparent coating for metal surfaces.

[0016] The method for preparing the easily cleanable transparent coating for metal surfaces, after the step of stirring at room temperature for 1-2 hours, further includes the following step: Add anti-scratch agents and anti-aging agents; When the total mass of the raw materials for the easy-to-clean transparent coating for metal surfaces is less than 100 parts, after the step of adding the anti-scratch agent and anti-aging agent, the following step is also included: The solvent is added to bring the total mass of the raw materials for the easy-to-clean transparent coating on the metal surface to 100 parts by weight.

[0017] Beneficial effects: The easy-to-clean transparent coating for metal surfaces of this application is a transparent solution that can be sprayed onto metal surfaces and quickly cured at room temperature to form an easy-to-clean coating. The formed easy-to-clean coating has the advantages of excellent hydrophobic and oleophobic properties, excellent adhesion properties, excellent wear resistance, and excellent scratch resistance. Attached Figure Description

[0018] Figure 1 This is a comparison diagram showing the anti-fouling effect of the easy-to-clean transparent coating formed by the metal surface easy-to-clean coating in Example 3 of this application. Detailed Implementation

[0019] This application provides an easy-to-clean transparent coating for metal surfaces and a method for preparing the same. To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following provides a more detailed description. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] This application provides an easy-to-clean transparent coating for metal surfaces, comprising the following raw materials by weight: Modified acrylate resin: 5-15 parts by weight; Aluminum sol: 5-15 parts by weight; Silica sol: 10-20 parts by weight; Silane coupling agent: 5-10 parts by weight; Anti-scratch additive: 1-5 parts by weight; Anti-aging agent: 0.5-1 part by weight; Solvent: 34-73.5 parts by weight; The total mass of all raw materials is 100 parts by weight.

[0021] The modified acrylate resin is obtained by polymerizing monomer raw materials in a solvent. The monomer raw materials include fluorinated acrylate monomers, long carbon chain acrylate monomers, and vinyl siloxane monomers.

[0022] Fluorinated acrylate monomers can be one or a mixture of two or more of the following: trifluoroethyl methacrylate, hexafluorobutyl methacrylate, hexafluorobutyl acrylate, and trifluoroethyl methacrylate. Long-chain fluorinated acrylate monomers with a higher number of carbon atoms have higher costs and greater health risks. Therefore, in this application, the fluorinated acrylate monomers used are fluorinated acrylate monomers with a fluorinated carbon chain of 3-6 carbon atoms.

[0023] Long-chain acrylate monomers have 12-18 carbon atoms, exhibit good hydrophobic properties, and are readily available from raw materials. Specifically, long-chain acrylate monomers can be one or a mixture of two or more of the following: dodecyl acrylate, tetradecyl acrylate, hexadecyl acrylate, and octadecyl acrylate.

[0024] Vinylsiloxane monomers can be one or a mixture of two or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, vinylmethyldiethoxysilane, etc.

[0025] Furthermore, based on the principle of easy-to-clean transparent coatings for metal surfaces, the monomer raw material usage of the modified acrylic resin is as follows: Fluorinated acrylate monomers: 1-5 parts by weight; Long-chain acrylate monomers: 1-5 parts by weight; Vinylsiloxane monomers: 1-10 parts by weight; The sum of the fluorinated acrylate monomers, long-chain acrylate monomers, and vinylsiloxane monomers is 5-15 parts by weight.

[0026] In this application, fluorinated acrylate monomers impart hydrophobic and oleophobic properties to the coating, while long-chain acrylate monomers provide hydrophobicity and flexibility. Vinylsiloxane monomers and long-chain acrylate monomers enhance the compatibility of the film-forming material with silica sol and alumina sol, as well as improve adhesion to the substrate. To achieve synergistic optimization of coating mechanical properties and raw material costs, the mass ratio of fluorinated acrylate monomers, long-chain acrylate monomers, and vinylsiloxane monomers is preferably 1:1:1, which achieves the optimal balance between cost and performance while ensuring coating performance.

[0027] Furthermore, the raw materials for modified acrylate resin also include an initiator. The amount of initiator added can be 1 wt% of the total mass of the monomer raw materials.

[0028] The initiator can be a conventional oily free radical initiator, specifically azobisisobutyronitrile or benzoyl peroxide.

[0029] In this application, the modified acrylate resin uses long carbon chains to enhance hydrophobicity and short fluorocarbon chains to enhance oleophobicity. The introduction of siloxane structures promotes crosslinking and uniform mixing of the organic resin with the modified silica and alumina. The abundant ester and epoxy groups in the coating contribute to strengthening the adhesion between the coating and the metal. Simultaneously, silica and alumina nanoparticles significantly enhance the coating's hardness and abrasion resistance. Furthermore, the addition of anti-scratch additives to the coating effectively prevents scratches.

[0030] The solvent can be ethanol.

[0031] The silane coupling agent can be one or a mixture of two or more of the following: methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, octyltrimethylsilane, 3-glycidyl etheroxypropyltrimethoxysilane (KH560 silane coupling agent), and 3-glycidyl etheroxypropyltriethoxysilane (KH561 silane coupling agent).

[0032] In this application, silica sol and alumina sol can be modified using the same silane coupling agent or different silane coupling agents. Specifically, when modifying silica sol and alumina sol, the amounts of each silane coupling agent must be controlled within a suitable ratio range. Specifically, the mass ratio of the silane coupling agent used to treat silica sol to the mass of silica sol is 1:3 to 1:1; the mass ratio of the silane coupling agent used to treat alumina sol to the mass of alumina sol is 1:5 to 1:1.

[0033] In the embodiments of this application, the alumina particle size of the aluminum sol is 10-30 nm, the solid content of the alumina is 30 wt%, and the pH is 4. Only aluminum sol with this particle size and pH will be relatively transparent and stable.

[0034] In the embodiments of this application, the silica sol has a silica particle size of 10-30 nm, a silica solid content of 30 wt%, and a pH of 2. Only silica sols with this particle size and pH will be relatively transparent and stable.

[0035] In this application, aluminum sol is used to increase the wear resistance of the coating. The preferred mass ratio between silica sol and aluminum sol is 3:1, which can optimize the hardness and wear resistance of the coating.

[0036] Anti-scratch additives can be one or a mixture of two or more of polydimethylsiloxane (silicone oil) and its modified forms, such as DC-51, BYK-378, Troysol Z370, and Sino® WE-D3502.

[0037] The anti-aging agent may be one or a mixture of two or more of Irganox® 1010, Hostavin® N30P, Tinuvin® NOR® 600, ADKSTAB AO-60 and HS-770.

[0038] This application also provides a method for preparing an easy-to-clean transparent coating for metal surfaces, including the following steps: An initiator was added to the solvent, and nitrogen gas was bubbled through the system for 1 hour. Then, the system was heated to reflux. Fluorinated acrylate monomers, long-chain acrylate monomers, and vinylsiloxane monomers were added dropwise simultaneously, controlling the dropping rate of each monomer. The reaction was carried out under reflux for 1-2 hours to obtain a modified acrylate resin solution. (The reaction time is calculated from the start of monomer addition; this reaction time is also the dropping time, and the addition is completed within 1-2 hours. The reaction is considered complete after the addition is finished.) A silane coupling agent was added to the silica sol, and the mixture was stirred at 300 r / min for 1 h at room temperature to obtain a modified silica sol. A silane coupling agent was added to the aluminum sol, and the mixture was stirred at 300 r / min for 1 h at room temperature to obtain the modified aluminum sol. Modified silica sol and modified aluminum sol are mixed, and then modified acrylic resin solution is added to adjust the pH to 3-5. The mixture is stirred at 300 r / min for 1-2 h at room temperature. Then, anti-scratch additives and anti-aging agents are added to obtain a transparent, easy-to-clean transparent coating for metal surfaces.

[0039] In this application, the three monomers are preferably added at the same rate. In the embodiments of this application, the addition rate is controlled at 30 mL / h.

[0040] In this application, the monomers can be added dropwise at a constant pressure using a dropping funnel or a peristaltic pump; alternatively, each of the three monomers can be prepared into a monomer solution of equal volume using a portion of the solvent, and then added dropwise at a constant pressure using a dropping funnel or a peristaltic pump. If the total mass of the raw materials for the easy-to-clean transparent coating for metal surfaces is less than 100 parts by weight, after adding the anti-scratch additive and anti-aging agent, the following steps may also be included: Add an appropriate amount of solvent to bring the total mass of the raw materials for the easy-to-clean transparent coating on the metal surface to 100 parts by weight.

[0041] The easy-to-clean transparent coating for metal surfaces disclosed in this application is prepared under specific reaction conditions from modified acrylic resin, silica sol, alumina sol, silane coupling agent, anti-scratch additive, and anti-aging agent. The modified acrylic resin is prepared by copolymerizing fluorinated acrylate monomers with long-chain acrylate monomers and vinyl siloxane monomers; the silica sol and alumina sol are pre-modified with silane coupling agents. The resulting easy-to-clean transparent coating for metal surfaces is a transparent solution that, when sprayed onto a metal surface, can rapidly cure at room temperature to form an easy-to-clean coating. The formed easy-to-clean coating can stably adhere to stainless steel and aluminum substrates, and being transparent, it does not obscure the original substrate color. Even after thousands of rubs, it maintains excellent hydrophobic, oleophobic, anti-graffiti, and scratch-resistant properties. The easy-to-clean transparent coating for metal surfaces disclosed in this application features a simple preparation method, transparency, and excellent hydrophobic and oleophobic properties, excellent adhesion, excellent wear resistance, and excellent scratch resistance.

[0042] The present application will be further described below through specific embodiments.

[0043] Example 1 By weight, 3 parts of hexafluorobutyl acrylate, 3 parts of dodecyl acrylate, and 3 parts of vinyltrimethoxysilane were placed in three constant-pressure dropping funnels. 40 parts of ethanol were added, along with 1 wt% of initiator (azobisisobutyronitrile) from the total monomer mass. The system was then purged with nitrogen for 1 hour, heated to reflux, and the three monomers were simultaneously added dropwise. The dropping rates of the three monomers were kept consistent, and the reaction was carried out under reflux for 1 hour to obtain a modified acrylate resin solution.

[0044] Take 15 parts of silica sol, add 5 parts of methyltrimethoxysilane, and stir at 300 r / min for 1 h at room temperature to obtain modified silica sol.

[0045] Take 5 parts of aluminum sol, add 1 part of KH560 silane coupling agent, and stir at 300 r / min for 1 h at room temperature to obtain modified aluminum sol.

[0046] The modified silica sol and modified aluminum sol were mixed together, and then a modified acrylic resin solution was added to adjust the pH to 4. The mixture was stirred at room temperature for 1.5 hours. Then, 1 part of anti-scratch additive (BYK-378) and 0.5 parts of anti-aging agent (Irganox®1010) were added, and an appropriate amount of ethanol was added to make the total mass of raw materials for easy-to-clean transparent coating for metal surfaces reach 100 parts by weight, thus obtaining easy-to-clean transparent coating for metal surfaces.

[0047] Example 2 By weight, 3 parts of trifluoroethyl acrylate, 3 parts of octadecyl acrylate, and 3 parts of vinyltrimethoxysilane were placed in three constant-pressure dropping funnels. 40 parts of ethanol were added, along with 1 wt% of initiator (azobisisobutyronitrile) from the total monomer mass. The system was then purged with nitrogen for 1 hour, heated to reflux, and the three monomers were simultaneously added dropwise. The dropping rates of the three monomers were kept consistent, and the reaction was carried out under reflux for 1 hour to obtain a modified acrylate resin solution.

[0048] Take 15 parts of silica sol, add 5 parts of methyltrimethoxysilane, and stir at 300 r / min for 1 h at room temperature to obtain modified silica sol.

[0049] Take 5 parts of aluminum sol, add 1 part of KH560 silane coupling agent, and stir at 300 r / min for 1 h at room temperature to obtain modified aluminum sol.

[0050] The modified silica sol and modified aluminum sol were mixed together, and then a modified acrylic resin solution was added to adjust the pH to 4. The mixture was stirred at room temperature for 1.5 hours. Then, 1 part of anti-scratch additive (BYK-378) and 0.5 parts of anti-aging agent (Irganox®1010) were added, and an appropriate amount of ethanol was added to make the total mass of raw materials for easy-to-clean transparent coating for metal surfaces reach 100 parts by weight, thus obtaining easy-to-clean transparent coating for metal surfaces.

[0051] Example 3 Five parts by weight of hexafluorobutyl acrylate, five parts by weight of dodecyl acrylate, and five parts by weight of vinyltrimethoxysilane were placed in three constant-pressure dropping funnels. Forty parts by weight of ethanol were added, along with 1 wt% of initiator (azobisisobutyronitrile) from the total monomer mass. The system was then purged with nitrogen for 1 hour, heated to reflux, and the three monomers were simultaneously added dropwise. The dropping rates of the three monomers were kept constant, and the reaction was carried out under reflux for 1 hour to obtain a modified acrylate resin solution.

[0052] Take 15 parts of silica sol, add 5 parts of methyltrimethoxysilane, and stir at 300 r / min for 1 h at room temperature to obtain modified silica sol.

[0053] Take 5 parts of aluminum sol, add 1 part of KH560 silane coupling agent, and stir at 300 r / min for 1 h at room temperature to obtain modified aluminum sol.

[0054] The modified silica sol and modified aluminum sol were mixed together, and then a modified acrylic resin solution was added to adjust the pH to 4. The mixture was stirred at room temperature for 1.5 hours. Then, 1 part of anti-scratch additive (BYK-378) and 0.5 parts of anti-aging agent (Irganox®1010) were added, and an appropriate amount of ethanol was added to make the total mass of raw materials for easy-to-clean transparent coating for metal surfaces reach 100 parts by weight, thus obtaining easy-to-clean transparent coating for metal surfaces.

[0055] Comparative Example 1 Six parts by weight of dodecyl acrylate and three parts by weight of vinyltrimethoxysilane were placed in two constant-pressure dropping funnels. Forty parts by weight of ethanol were added, along with 1 wt% of the total monomer mass of initiator (azobisisobutyronitrile). The system was purged with nitrogen for 1 hour, and then heated to reflux. The two monomers were simultaneously added dropwise to the system. The dropping rates of the two monomers were kept consistent, and the reaction was carried out under reflux for 1 hour.

[0056] Take 15 parts of silica sol, add 5 parts of methyltrimethoxysilane, and stir at 300 r / min for 1 h at room temperature to obtain modified silica sol.

[0057] Take 5 parts of aluminum sol, add 1 part of KH560 silane coupling agent, and stir at 300 r / min for 1 h at room temperature to obtain modified aluminum sol.

[0058] The modified silica sol and modified aluminum sol were mixed together, and then a modified acrylic resin solution was added to adjust the pH to 4. The mixture was stirred at room temperature for 1.5 hours. Then, 1 part of anti-scratch additive (BYK-378) and 0.5 parts of anti-aging agent (Irganox®1010) were added, and an appropriate amount of ethanol was added to make the total mass of raw materials for easy-to-clean transparent coating for metal surfaces reach 100 parts by weight, thus obtaining easy-to-clean transparent coating for metal surfaces.

[0059] Comparative Example 2 By weight, 3 parts of hexafluorobutyl acrylate, 3 parts of dodecyl acrylate, and 3 parts of vinyltrimethoxysilane were placed in three constant-pressure dropping funnels. 40 parts of ethanol were added, along with 1 wt% of initiator (azobisisobutyronitrile) from the total monomer mass. The system was then purged with nitrogen for 1 hour, heated to reflux, and the three monomers were simultaneously added dropwise. The dropping rates of the three monomers were kept consistent, and the reaction was carried out under reflux for 1 hour to obtain a modified acrylate resin solution.

[0060] Take 15 parts of silica sol, add 10 parts of methyltrimethoxysilane and 1 part of KH560 silane coupling agent, and stir at 300 r / min for 1 h at room temperature.

[0061] Modified silica sol was added to modified acrylic resin solution, pH was adjusted to 4, and stirred at room temperature for 1.5 h. Then, 1 part of anti-scratch agent (BYK-378) and 0.5 parts of anti-aging agent (Irganox® 1010) were added, and an appropriate amount of ethanol was added to make the total mass of raw materials for easy-to-clean transparent coating for metal surfaces reach 100 parts by weight, thus obtaining easy-to-clean transparent coating for metal surfaces.

[0062] Comparative Example 3 Five parts by weight of hexafluorobutyl acrylate and five parts by weight of dodecyl acrylate were placed in two constant-pressure dropping funnels. Forty parts by weight of ethanol were added, along with 1 wt% of initiator (azobisisobutyronitrile) from the total monomer mass. The system was then purged with nitrogen for 1 hour, heated to reflux, and the two monomers were simultaneously added dropwise. The dropping rates of the two monomers were kept consistent, and the reaction was carried out under reflux for 1 hour to obtain a modified acrylate resin solution.

[0063] Take 15 parts of silica sol, add 5 parts of methyltrimethoxysilane, and stir at 300 r / min for 1 h at room temperature to obtain modified silica sol.

[0064] Take 5 parts of aluminum sol, add 1 part of KH560 silane coupling agent, and stir at 300 r / min for 1 h at room temperature to obtain modified aluminum sol.

[0065] The modified silica sol and modified aluminum sol were mixed together, and then a modified acrylic resin solution was added to adjust the pH to 4. The mixture was stirred at room temperature for 1.5 hours. Then, 1 part of anti-scratch additive (BYK-378) and 0.5 parts of anti-aging agent (Irganox®1010) were added, and an appropriate amount of ethanol was added to make the total mass of raw materials for easy-to-clean transparent coating for metal surfaces reach 100 parts by weight, thus obtaining easy-to-clean transparent coating for metal surfaces.

[0066] Performance testing: Surface treatment of metal substrate (aluminum plate): Clean the metal surface of dust and oil with water and ethanol, and use sandpaper to sand off the original coating or rust on the surface of the metal substrate to fully expose the surface of the metal substrate.

[0067] Coating preparation: A multi-pass thin-spray process is used to apply 10-20 mL / 100 cm thick coating to the surface of the metal substrate. 2 Apply the total amount of coating, spray the easy-clean transparent coating onto the metal surface; then wet the scraper with the easy-clean transparent coating onto the metal surface, first apply horizontally, then vertically to ensure even coating on the substrate surface, and cure at room temperature for 24 hours.

[0068] The performance indicators of the easy-clean coatings formed by the easy-clean transparent coatings for metal surfaces prepared in Examples 1-3 and Comparative Examples 1-3 were tested. The test methods are shown in Table 1, and the test results are shown in Table 2.

[0069] Table 1

[0070] Table 2

[0071] In this application, a specific modified acrylate resin is combined with silica nanoparticles and alumina nanoparticles modified with silane coupling agents. After hydrolysis and cross-linking curing, a transparent coating with a hardness of 5H can be formed, with an initial hydrophobic angle of up to 123° and an oil resistance level of 7.

[0072] As can be seen from the data in Examples 1-3 in Table 2, increasing the number of carbon atoms in the aliphatic long carbon chain in the modified acrylic resin and increasing the content of short fluorocarbon chains can significantly enhance the hydrophobic and oil-repellent properties of the coating.

[0073] Using an oil-based marker, lines were drawn on both an aluminum plate without the easy-clean transparent metal surface coating and an aluminum plate coated with the easy-clean transparent metal surface coating of Example 3 to form an easy-clean coating. Figure 1 It is clearly visible (the left image shows an aluminum plate without the easy-clean transparent coating for metal surfaces, and the right image shows an aluminum plate with the easy-clean transparent coating for metal surfaces of Example 3) that on the aluminum plate with the easy-clean coating, oil-based markers can only leave very shallow marks, which can be easily wiped away. Moreover, the easy-clean coating formed by the easy-clean transparent coating for metal surfaces of Example 3 has excellent adhesion; after 30,000 rubs, its water droplet angle can reach 116°, and its oil resistance level can be maintained at level 6.

[0074] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of this application.

Claims

1. A transparent coating for easy cleaning of metal surfaces, characterized in that, By weight, it includes the following ingredients: Modified acrylate resin: 5-15 parts by weight; Aluminum sol: 5-15 parts by weight; Silica sol: 10-20 parts by weight; Silane coupling agent: 5-10 parts by weight; Solvent: 34-73.5 parts by weight; The modified acrylate resin is obtained by polymerizing monomer raw materials in the solvent, and the monomer raw materials include fluorinated acrylate monomers, long carbon chain acrylate monomers, and vinylsiloxane monomers.

2. The easy-to-clean transparent coating for metal surfaces according to claim 1, characterized in that, The easily cleanable transparent coating for metal surfaces, by weight, comprises the following amounts of monomeric raw materials: The fluorinated acrylate monomer: 1-5 parts by weight; The long-chain acrylate monomer: 1-5 parts by weight; The vinylsiloxane monomer: 1-10 parts by weight; The raw materials for the modified acrylate resin also include an initiator; The amount of initiator added is 1 wt% of the total monomer mass.

3. The easy-to-clean transparent coating for metal surfaces according to claim 1, characterized in that, The long-chain acrylate monomers have 12-18 carbon atoms. The fluorinated acrylate monomers have a fluorocarbon chain with 3-6 carbon atoms.

4. The easy-to-clean transparent coating for metal surfaces according to claim 1, characterized in that, The fluorinated acrylate monomer is one or a mixture of two or more of the following: trifluoroethyl methacrylate, hexafluorobutyl methacrylate, hexafluorobutyl acrylate, and trifluoroethyl methacrylate. The long-chain acrylate monomer is one or a mixture of two or more of dodecyl acrylate, tetradecyl acrylate, hexadecyl acrylate, and octadecyl acrylate; The vinylsiloxane monomers are one or a mixture of two or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, and vinylmethyldiethoxysilane.

5. The easy-to-clean transparent coating for metal surfaces according to claim 1, characterized in that, The mass ratio of the fluorinated acrylate monomer, the long-chain acrylate monomer, and the vinylsiloxane monomer is 1:1:

1.

6. The easy-to-clean transparent coating for metal surfaces according to claim 1, characterized in that, The silane coupling agent is one or a mixture of two or more of methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, octyltrimethylsilane, 3-glycidyl etheroxypropyltrimethoxysilane, and 3-glycidyl etheroxypropyltriethoxysilane. The silane coupling agent is used to modify the silica sol and the aluminum sol. The silica sol and the aluminum sol are modified using the same or different silane coupling agents; The mass ratio of the silane coupling agent used to treat the silica sol to the mass of the silica sol is 1:3 to 1:1; The mass ratio of the silane coupling agent used to treat the aluminum sol to the mass of the aluminum sol is 1:5 to 1:

1.

7. The easy-to-clean transparent coating for metal surfaces according to claim 1, characterized in that, The solvent is ethanol.

8. The easy-to-clean transparent coating for metal surfaces according to claim 1, characterized in that, The easy-to-clean transparent coating for metal surfaces, by weight, also includes the following raw materials: Anti-scratch additive: 1-5 parts by weight; Anti-aging agent: 0.5-1 part by weight; The anti-scratch additive is one or a mixture of two or more of polydimethylsiloxane (silicone oil) and its modifiers; The anti-aging agent is one or a mixture of two or more of Irganox® 1010, Hostavin® N30P, Tinuvin® NOR® 600, ADK STABAO-60, and HS-770.

9. A method for preparing an easy-to-clean transparent coating for metal surfaces as described in any one of claims 1-8, characterized in that, Includes the following steps: An initiator is added to the solvent, nitrogen gas is bubbled through the system, and then the system is heated to reflux. Fluorinated acrylate monomers, long-chain acrylate monomers, and vinylsiloxane monomers are added dropwise at the same time. The reaction is carried out under reflux for 1-2 hours to obtain a modified acrylate resin solution. A silane coupling agent was added to the silica sol, and the mixture was stirred at room temperature for 1 hour to obtain a modified silica sol. A silane coupling agent was added to the aluminum sol, and the mixture was stirred at room temperature for 1 hour to obtain the modified aluminum sol. The modified silica sol and the modified aluminum sol are mixed, and then the modified acrylate resin solution is added. The pH is adjusted to 3-5, and the mixture is stirred at room temperature for 1-2 hours to obtain the easy-to-clean transparent coating for metal surfaces.

10. The method for preparing an easy-to-clean transparent coating for metal surfaces according to claim 9, characterized in that, Following the step of stirring at room temperature for 1-2 hours, the following steps are also included: Add anti-scratch agents and anti-aging agents; When the total mass of the raw materials for the easy-to-clean transparent coating for metal surfaces is less than 100 parts, after the step of adding the anti-scratch agent and anti-aging agent, the following step is also included: The solvent is added to bring the total mass of the raw materials for the easy-to-clean transparent coating on the metal surface to 100 parts by weight.

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