Fluorocarbon coating for aluminum ceiling surface and preparation method thereof

Abstract

This invention belongs to the field of fluorocarbon coating technology, specifically relating to a fluorocarbon coating for aluminum ceiling surfaces and its preparation method. The fluorocarbon coating comprises component A and component B; component A includes the following components by weight: 60-70 parts of water-based fluorocarbon resin; 8-10 parts of modified nano-titanium dioxide; 3-5 parts of modified silane; 1-2 parts of dispersant; 0.5-1 part of leveling agent; 0.3-0.5 parts of defoamer; and 10-15 parts of deionized water; component B includes the following components by weight: 12-15 parts of curing agent. This invention uses water-based fluorocarbon resin as the main raw material, and by adding modified nano-titanium dioxide and modified silane, obtains a fluorocarbon coating with excellent hardness, impact resistance, adhesion, aging resistance, salt spray resistance, and antibacterial properties. This fluorocarbon coating also has the advantages of good environmental friendliness and no baking required, especially excellent adhesion to aluminum-magnesium alloy substrates, making it suitable for the protection of aluminum ceiling surfaces.

Description

Technical Field

[0001] This invention belongs to the field of fluorocarbon coating technology, specifically relating to a fluorocarbon coating for aluminum ceiling surfaces and its preparation method. Background Technology

[0002] Fluorocarbon coatings, also known as fluorocarbon paints, fluoropolymer coatings, or fluororesin coatings, are coatings that use fluoropolymers as the main film-forming substance. Fluorocarbon coatings contain a large number of strong, low-polarity CF chemical bonds, exhibiting excellent weather resistance, low-temperature resistance, and chemical resistance. They are widely used in construction, chemical industry, electrical and electronic industry, aerospace, and other fields. Classified by film-forming resin, fluorocarbon coatings mainly include polytetrafluoroethylene (PTFE) coatings, polyvinylidene fluoride (PVDF) coatings, and copolymers of fluoroolefins with alkyl vinyl ethers or esters (FEVE). Classified by solvent type, fluorocarbon coatings are divided into oil-based fluorocarbon coatings and water-based fluorocarbon coatings. Oil-based fluorocarbon coatings use organic solvents as diluents, resulting in higher emissions of volatile organic compounds (VOCs), which are environmentally unfriendly. Water-based fluorocarbon coatings use water as a diluent, offering high environmental friendliness, but their weather resistance and adhesion still lag behind oil-based fluorocarbon coatings, limiting their application to some extent.

[0003] Chinese patent application CN202211319117.7 discloses a room-temperature curing fluorocarbon coating and its preparation method, comprising the following raw materials: 50-70 parts by weight of modified fluorocarbon resin, 0.5-4 parts by weight of dispersant, 0.1-0.5 parts by weight of defoamer, 0.2-1 parts by weight of wetting agent, 0.1-0.8 parts by weight of thickener, 15-35 parts by weight of filler, 3-8 parts by weight of curing agent, and 4-10 parts by weight of water. The filler is a mixture of modified kaolin and titanium dioxide. The modified kaolin is prepared by first synthesizing layered zirconium phosphate, then adding ethyltrimethylammonium bromide and kaolin, allowing ethyltrimethylammonium bromide to intercalate between the layered zirconium phosphate and kaolin layers. Magnolol is then added, which improves the antibacterial properties of the fluorocarbon coating, but its antibacterial effect against Staphylococcus aureus is less than 9%. 0%; Chinese patent application CN202410250279.2 discloses a water-based FEVE baking-type fluorocarbon coating and its preparation method, including: water-based fluorocarbon emulsion, deionized water, amino resin, additives and nano titanium dioxide. The additives include: pigments, wetting agents, dispersants, defoamers, antifreeze agents, film-forming aids, thickening rheology modifiers, curing agents and bactericides and fungicides, wherein the bactericide and fungicide is phenol. This patent uses water-based FEVE dispersion as the main body, which reduces VOC emissions. Although it can achieve the performance of oil-based FEVE coating by adding amino resin and baking at high temperature, it is inconvenient to apply. At the same time, the bactericide and fungicide effect achieved by using phenol as a bactericide and fungicide is insufficient. Therefore, it is necessary to develop an environmentally friendly water-based fluorocarbon coating with high antibacterial properties and no baking required. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a fluorocarbon coating for aluminum ceiling surfaces and its preparation method. This invention uses water-based fluorocarbon resin as the main raw material and adds modified nano-titanium dioxide and modified silane to obtain a fluorocarbon coating with excellent hardness, impact resistance, adhesion, aging resistance, salt spray resistance, and antibacterial properties. This fluorocarbon coating also has the advantages of good environmental protection and no baking required, and has particularly excellent adhesion to aluminum-magnesium alloy substrates, making it suitable for the protection of aluminum ceiling surfaces.

[0005] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0006] A fluorocarbon coating for aluminum ceiling surfaces, the fluorocarbon coating comprising component A and component B; component A comprising the following components by weight: 60-70 parts of waterborne fluorocarbon resin; 8-10 parts of modified nano-titanium dioxide; 3-5 parts of modified silane; 1-2 parts of dispersant; 0.5-1 part of leveling agent; 0.3-0.5 parts of defoamer; and 10-15 parts of deionized water; component B comprising the following components by weight: 12-15 parts of curing agent.

[0007] Furthermore, the dispersant is any one or a mixture of several of BYK-110, BYK-161, and BYK-192.

[0008] Furthermore, the leveling agent is any one or a mixture of several of EFKA-3777, EFKA-3030, and AKN-1377.

[0009] Furthermore, the defoamer is an organosilicon defoamer; the curing agent is an HDI trimer curing agent.

[0010] Furthermore, the preparation method of the modified nano-titanium dioxide is as follows:

[0011] S1. Add nano-titanium dioxide to Tris-HCl buffer, disperse evenly, then add dopamine, and shake at room temperature for 20-22 hours to obtain polydopamine-nano-titanium dioxide.

[0012] S2. Add polydopamine-nano titanium dioxide to ethanol and disperse it evenly. Then add 2-chloro-5-cyanobenzimidazole and triethylamine. Stir and react at 70-75℃ for 5-6 hours to obtain modified nano titanium dioxide.

[0013] Further, in step S1, the mass ratio of nano-titanium dioxide to Tris-HCl buffer is 1:10-12; the concentration of dopamine in the Tris-HCl buffer is 2-3 mg / mL; and the pH value of the Tris-HCl buffer is 8.5-8.6, and the concentration is 10-15 mmol / L.

[0014] Furthermore, in step S2, the mass ratio of polydopamine-nano titanium dioxide, 2-chloro-5-cyanobenzimidazole, and triethylamine is 1:0.3-0.4:0.2-0.3.

[0015] Further, the modified silane is prepared by adding triphenylphosphine to anhydrous N,N-dimethylformamide under nitrogen protection, stirring until homogeneous, adding 3-chloropropyltrimethoxysilane at 110-115°C, and stirring for 20-22 hours to obtain the modified silane.

[0016] Furthermore, the molar ratio of triphenylphosphine to 3-chloropropyltrimethoxysilane is 1:1-1.1.

[0017] The present invention also provides a method for preparing a fluorocarbon coating for aluminum ceiling surfaces, comprising the following steps: mixing waterborne fluorocarbon resin, modified nano titanium dioxide, modified silane, dispersant, leveling agent, defoamer and deionized water uniformly according to the weight ratio to obtain component A; then mixing component A and component B uniformly to obtain a fluorocarbon coating for aluminum ceiling surfaces.

[0018] The present invention has the following beneficial effects:

[0019] 1. This invention forms polydopamine on the surface of nano-titanium dioxide through a self-polymerization reaction, achieving polydopamine coating of nano-titanium dioxide to obtain polydopamine-nano-titanium dioxide. The polydopamine structure on its surface contains active hydroxyl and amino groups. By reacting the amino group with 2-chloro-5-cyanobenzimidazole, cyano and benzimidazole groups are further introduced into the polydopamine-nano-titanium dioxide to obtain modified nano-titanium dioxide. The modified nano-titanium dioxide obtained by this invention contains a polydopamine structure with good adhesion and antibacterial effect, benzimidazole group with good aging and corrosion resistance, and cyano group. In addition, this invention also prepares modified silane by reacting triphenylphosphine with 3-chloropropyltrimethoxysilane. The modified silane prepared contains quaternary phosphonium salt group and silanoxy group with good antibacterial effect.

[0020] 2. This invention adds modified nano-titanium dioxide and modified silane to fluorocarbon coatings to modify the coatings. The polydopamine structure can further improve the adhesion of the fluorocarbon coatings, and together with the quaternary phosphonium salt groups, it can significantly enhance the antibacterial properties of the fluorocarbon coatings. The benzimidazole groups can also further improve the aging resistance and salt spray resistance of the fluorocarbon coatings. The cyano groups in the modified nano-titanium dioxide can also participate in the curing and crosslinking of the HDI trimer curing agent during the curing of the fluorocarbon coating, increasing the crosslinking density of the paint film. At the same time, the silanol groups generated by the hydrolysis of silane groups are covalently bonded to the active groups in the fluorocarbon coating and the substrate surface, promoting the formation of the paint film network structure, enhancing the compactness of the paint film, and helping to improve the hardness, impact resistance and other properties of the paint film.

[0021] 3. This invention uses water-based fluorocarbon resin as the main raw material, and by adding modified nano-titanium dioxide and modified silane, it obtains a fluorocarbon coating with excellent hardness, impact resistance, adhesion, aging resistance, salt spray resistance and antibacterial properties. The fluorocarbon coating also has the advantages of good environmental protection and no baking required. In particular, it has excellent adhesion to aluminum-magnesium alloy substrates and is suitable for the protection of aluminum ceiling surfaces. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the technical solution of this invention, all chemical reagents used are commercially available. Among them, the water-based fluorocarbon resin was purchased from Shanghai Deyude Trading Co., Ltd. (model CF-801); the organosilicon defoamer was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; the HDI trimer curing agent CAS number 3779-63-3; the Tris-HCl buffer CAS number 5704-04-1; the nano titanium dioxide was purchased from Shanghai Jiubang Chemical Co., Ltd.; the dopamine CAS number 51-61-6; the triethylamine CAS number 121-44-8; the 2-chloro-5-cyanobenzimidazole CAS number 401567-00-8; the triphenylphosphine CAS number 603-35-0; the 3-chloropropyltrimethoxysilane CAS number 2530-87-2; the ethanol CAS number 64-17-5; and the N,N-dimethylformamide CAS number 68-12-2.

[0024] Example 1

[0025] A fluorocarbon coating for aluminum ceiling surfaces includes component A and component B. Component A includes the following components by weight: 70 parts of waterborne fluorocarbon resin; 10 parts of modified nano titanium dioxide; 5 parts of modified silane; 2 parts of dispersant; 0.8 parts of leveling agent; 0.5 parts of defoamer; and 15 parts of deionized water. Component B includes the following components by weight: 15 parts of curing agent.

[0026] The dispersant is BYK-110; the leveling agent is AKN-1377; the defoamer is an organosilicon defoamer; and the curing agent is an HDI trimer curing agent.

[0027] The present invention also provides a method for preparing a fluorocarbon coating for aluminum ceiling surfaces, comprising the following steps: mixing waterborne fluorocarbon resin, modified nano titanium dioxide, modified silane, dispersant, leveling agent, defoamer and deionized water uniformly according to the weight ratio to obtain component A; then mixing component A and component B uniformly to obtain a fluorocarbon coating for aluminum ceiling surfaces.

[0028] The preparation method of modified nano-titanium dioxide is as follows:

[0029] S1. Add nano-titanium dioxide to Tris-HCl buffer and disperse evenly. Then add dopamine and shake at room temperature for 22 hours. After the reaction is complete, centrifuge, wash the product with water, and dry to obtain polydopamine-nano-titanium dioxide. The mass ratio of nano-titanium dioxide to Tris-HCl buffer is 1:12. The concentration of dopamine in Tris-HCl buffer is 3 mg / mL. The pH value of Tris-HCl buffer is 8.5 and the concentration is 15 mmol / L.

[0030] S2. Add polydopamine-nano titanium dioxide to ethanol and disperse evenly. Then add 2-chloro-5-cyanobenzimidazole and triethylamine. Stir and react at 75°C for 5 hours. After the reaction is complete, centrifuge, wash the product with water and ethanol, and dry to obtain modified nano titanium dioxide. The mass ratio of polydopamine-nano titanium dioxide, 2-chloro-5-cyanobenzimidazole and triethylamine is 1:0.4:0.3; the mass ratio of polydopamine-nano titanium dioxide and ethanol is 1:20.

[0031] The modified silane was prepared as follows: Under nitrogen protection, 26.3 g of triphenylphosphine was added to 500 mL of anhydrous N,N-dimethylformamide, stirred until homogeneous, and then 21.9 g of [unspecified substance] was added at 110 °C. 3-Chloropropyltrimethoxysilane was stirred and reacted for 20 h. After the reaction was completed, N,N-dimethylformamide was removed, and diethyl ether was added and stirred to remove impurities. After filtration and drying, 37.4 g of modified silane was obtained. The molar ratio of triphenylphosphine to 3-chloropropyltrimethoxysilane was 1:1.1. Modified silane: ESI (m / z): 461.1 [M+H]+, 1H-NMR (600MHz, DMSO-d6, δppm): 7.35-7.37 (m, 9H), 7.33 (d, J=8.4Hz, 6H), 3.55 (s, 9H), 2.46-2.50 (m, 2H), 1.30-1.33 (m, 2H), 0.56-0.59 (m, 2H). The reaction process was as follows:

[0032] .

[0033] Example 2

[0034] A fluorocarbon coating for aluminum ceiling surfaces includes component A and component B. Component A includes the following components by weight: 65 parts of waterborne fluorocarbon resin; 9 parts of modified nano titanium dioxide; 4 parts of modified silane; 1 part of dispersant; 1 part of leveling agent; 0.4 parts of defoamer; and 13 parts of deionized water. Component B includes the following components by weight: 14 parts of curing agent.

[0035] The dispersant is BYK-192; the leveling agent is EFKA-3777; the defoamer is an organosilicon defoamer; and the curing agent is an HDI trimer curing agent.

[0036] The present invention also provides a method for preparing a fluorocarbon coating for aluminum ceiling surfaces, comprising the following steps: mixing waterborne fluorocarbon resin, modified nano titanium dioxide, modified silane, dispersant, leveling agent, defoamer and deionized water uniformly according to the weight ratio to obtain component A; then mixing component A and component B uniformly to obtain a fluorocarbon coating for aluminum ceiling surfaces.

[0037] The preparation method of modified nano-titanium dioxide is as follows:

[0038] S1. Add nano-titanium dioxide to Tris-HCl buffer and disperse evenly. Then add dopamine and shake at room temperature for 20 hours. After the reaction is complete, centrifuge, wash the product with water, and dry to obtain polydopamine-nano-titanium dioxide. The mass ratio of nano-titanium dioxide to Tris-HCl buffer is 1:10; the concentration of dopamine in Tris-HCl buffer is 2.5 mg / mL; the pH of Tris-HCl buffer is 8.6 and the concentration is 10 mmol / L.

[0039] S2. Add polydopamine-nano titanium dioxide to ethanol and disperse evenly. Then add 2-chloro-5-cyanobenzimidazole and triethylamine. Stir and react at 70°C for 6 hours. After the reaction is complete, centrifuge, wash the product with water and ethanol, and dry to obtain modified nano titanium dioxide. The mass ratio of polydopamine-nano titanium dioxide, 2-chloro-5-cyanobenzimidazole and triethylamine is 1:0.35:0.25; the mass ratio of polydopamine-nano titanium dioxide and ethanol is 1:20.

[0040] The preparation method of the modified silane is the same as that in Example 1.

[0041] Example 3

[0042] A fluorocarbon coating for aluminum ceiling surfaces includes component A and component B. Component A includes the following components by weight: 60 parts of waterborne fluorocarbon resin; 8 parts of modified nano titanium dioxide; 3 parts of modified silane; 1.5 parts of dispersant; 0.5 parts of leveling agent; 0.3 parts of defoamer; and 10 parts of deionized water. Component B includes the following components by weight: 12 parts of curing agent.

[0043] The dispersant is BYK-161; the leveling agent is EFKA-3030; the defoamer is an organosilicon defoamer; and the curing agent is an HDI trimer curing agent.

[0044] The present invention also provides a method for preparing a fluorocarbon coating for aluminum ceiling surfaces, comprising the following steps: mixing waterborne fluorocarbon resin, modified nano titanium dioxide, modified silane, dispersant, leveling agent, defoamer and deionized water uniformly according to the weight ratio to obtain component A; then mixing component A and component B uniformly to obtain a fluorocarbon coating for aluminum ceiling surfaces.

[0045] The preparation method of modified nano-titanium dioxide is as follows:

[0046] S1. Add nano-titanium dioxide to Tris-HCl buffer and disperse evenly. Then add dopamine and shake at room temperature for 21 hours. After the reaction is complete, centrifuge, wash the product with water, and dry to obtain polydopamine-nano-titanium dioxide. The mass ratio of nano-titanium dioxide to Tris-HCl buffer is 1:11. The concentration of dopamine in Tris-HCl buffer is 2 mg / mL. The pH of Tris-HCl buffer is 8.55 and the concentration is 12 mmol / L.

[0047] S2. Add polydopamine-nano titanium dioxide to ethanol and disperse evenly. Then add 2-chloro-5-cyanobenzimidazole and triethylamine. Stir and react at 72°C for 5.5 h. After the reaction is complete, centrifuge, wash the product with water and ethanol, and dry to obtain modified nano titanium dioxide. The mass ratio of polydopamine-nano titanium dioxide, 2-chloro-5-cyanobenzimidazole and triethylamine is 1:0.3:0.2; the mass ratio of polydopamine-nano titanium dioxide and ethanol is 1:20.

[0048] The preparation method of the modified silane is the same as that in Example 1.

[0049] Example 4

[0050] A fluorocarbon coating for aluminum ceiling surfaces includes component A and component B. Component A includes the following components by weight: 70 parts of waterborne fluorocarbon resin; 9 parts of modified nano titanium dioxide; 3 parts of modified silane; 2 parts of dispersant; 0.6 parts of leveling agent; 0.3 parts of defoamer; and 14 parts of deionized water. Component B includes the following components by weight: 13 parts of curing agent.

[0051] The dispersant is BYK-110; the leveling agent is EFKA-3030; the defoamer is an organosilicon defoamer; and the curing agent is an HDI trimer curing agent.

[0052] The present invention also provides a method for preparing a fluorocarbon coating for aluminum ceiling surfaces, comprising the following steps: mixing waterborne fluorocarbon resin, modified nano titanium dioxide, modified silane, dispersant, leveling agent, defoamer and deionized water uniformly according to the weight ratio to obtain component A; then mixing component A and component B uniformly to obtain a fluorocarbon coating for aluminum ceiling surfaces.

[0053] The preparation method of modified nano-titanium dioxide is as follows:

[0054] S1. Add nano-titanium dioxide to Tris-HCl buffer and disperse evenly. Then add dopamine and shake at room temperature for 22 hours. After the reaction is complete, centrifuge, wash the product with water, and dry to obtain polydopamine-nano-titanium dioxide. The mass ratio of nano-titanium dioxide to Tris-HCl buffer is 1:10. The concentration of dopamine in Tris-HCl buffer is 2 mg / mL. The pH value of Tris-HCl buffer is 8.5 and the concentration is 13 mmol / L.

[0055] S2. Add polydopamine-nano titanium dioxide to ethanol and disperse evenly. Then add 2-chloro-5-cyanobenzimidazole and triethylamine. Stir and react at 75°C for 6 hours. After the reaction is complete, centrifuge, wash the product with water and ethanol, and dry to obtain modified nano titanium dioxide. The mass ratio of polydopamine-nano titanium dioxide, 2-chloro-5-cyanobenzimidazole and triethylamine is 1:0.35:0.3; the mass ratio of polydopamine-nano titanium dioxide and ethanol is 1:20.

[0056] The preparation method of the modified silane is the same as that in Example 1.

[0057] Comparative Example 1

[0058] Compared with Example 1, the A component of the fluorocarbon coating in this comparative example is different.

[0059] A fluorocarbon coating for aluminum ceiling surfaces includes component A and component B. Component A includes the following components by weight: 70 parts of waterborne fluorocarbon resin; 10 parts of nano titanium dioxide; 5 parts of modified silane; 2 parts of dispersant; 0.8 parts of leveling agent; 0.5 parts of defoamer; and 15 parts of deionized water. Component B includes the following components by weight: 15 parts of curing agent.

[0060] The dispersant is BYK-110; the leveling agent is AKN-1377; the defoamer is an organosilicon defoamer; and the curing agent is an HDI trimer curing agent.

[0061] The present invention also provides a method for preparing a fluorocarbon coating for aluminum ceiling surfaces, which is the same as in Example 1.

[0062] The preparation method of the modified silane is the same as that in Example 1.

[0063] Comparative Example 2

[0064] Compared with Example 1, the A component of the fluorocarbon coating in this comparative example is different.

[0065] A fluorocarbon coating for aluminum ceiling surfaces includes component A and component B. Component A includes the following components by weight: 70 parts of waterborne fluorocarbon resin; 10 parts of modified nano titanium dioxide; 2 parts of dispersant; 0.8 parts of leveling agent; 0.5 parts of defoamer; and 15 parts of deionized water. Component B includes the following components by weight: 15 parts of curing agent.

[0066] The dispersant is BYK-110; the leveling agent is AKN-1377; the defoamer is an organosilicon defoamer; and the curing agent is an HDI trimer curing agent.

[0067] The present invention also provides a method for preparing a fluorocarbon coating for aluminum ceiling surfaces, which is the same as in Example 1.

[0068] The preparation method of modified nano-titanium dioxide is the same as in Example 1.

[0069] Comparative Example 3

[0070] Compared with Example 1, the A component of the fluorocarbon coating in this comparative example is different.

[0071] A fluorocarbon coating for aluminum ceiling surfaces includes component A and component B. Component A includes the following components by weight: 70 parts of waterborne fluorocarbon resin; 10 parts of nano titanium dioxide; 2 parts of dispersant; 0.8 parts of leveling agent; 0.5 parts of defoamer; and 15 parts of deionized water. Component B includes the following components by weight: 15 parts of curing agent.

[0072] The dispersant is BYK-110; the leveling agent is AKN-1377; the defoamer is an organosilicon defoamer; and the curing agent is an HDI trimer curing agent.

[0073] The present invention also provides a method for preparing a fluorocarbon coating for aluminum ceiling surfaces, which is the same as in Example 1.

[0074] Test case

[0075] The hardness, impact resistance, adhesion, aging resistance, salt spray resistance, and antibacterial properties of the fluorocarbon coatings in Examples 1 to 4 and Comparative Examples 1 to 4 were tested. Hardness was tested according to GB / T 6739-2006; impact resistance according to GB / T 1732-2020; adhesion according to GB / T 9286-2021 (cross-cut test using aluminum-magnesium alloy plate); aging resistance according to GB / T 1865-2009 (artificial climate aging 3000h); salt spray resistance according to GB / T 10125-2021 (900h); and antibacterial properties according to GB / T 21866-2008. The test results are shown in Table 1 below.

[0076] Table 1

[0077]

[0078] As shown in Table 1, the fluorocarbon coatings of Examples 1 to 4 of this invention exhibit excellent hardness, impact resistance, adhesion, aging resistance, salt spray resistance, and antibacterial properties. Compared with Comparative Examples 1 to 3, Example 1 incorporates modified nano-titanium dioxide and modified silane. The polydopamine structure further enhances the adhesion of the fluorocarbon coating, and, in conjunction with the quaternary phosphonium salt group, significantly strengthens its antibacterial properties. The benzimidazole group further improves the aging resistance and salt spray resistance of the fluorocarbon coating. The cyano groups in the modified nano-titanium dioxide can also participate in the curing and crosslinking of the HDI trimer curing agent during the curing of the fluorocarbon coating, increasing the crosslinking density of the paint film. Simultaneously, the silanol groups generated by the hydrolysis of silaneoxy groups covalently bond with the active groups in the fluorocarbon coating and the substrate surface, promoting the formation of the paint film network structure, enhancing the density of the paint film, and contributing to improving the hardness, impact resistance, and other properties of the paint film.

[0079] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fluorocarbon coating for aluminum ceiling surfaces, characterized in that, The fluorocarbon coating comprises component A and component B. Component A comprises the following components by weight: 60-70 parts of waterborne fluorocarbon resin; 8-10 parts of modified nano-titanium dioxide; 3-5 parts of modified silane; 1-2 parts of dispersant; 0.5-1 part of leveling agent; 0.3-0.5 parts of defoamer; and 10-15 parts of deionized water. Component B comprises the following components by weight: 12-15 parts of curing agent. The modified nano-titanium dioxide was prepared by the following method: S1. Add nano-titanium dioxide to Tris-HCl buffer, disperse evenly, then add dopamine, and shake at room temperature for 20-22 hours to obtain polydopamine-nano-titanium dioxide. S2. Add polydopamine-nano titanium dioxide to ethanol, disperse evenly, then add 2-chloro-5-cyanobenzimidazole and triethylamine, stir and react at 70-75℃ for 5-6 hours to obtain modified nano titanium dioxide. The modified silane was prepared by the following method: under nitrogen protection, triphenylphosphine was added to anhydrous N,N-dimethylformamide and stirred until homogeneous. Then, 3-chloropropyltrimethoxysilane was added at 110-115°C and stirred for 20-22 hours to obtain the modified silane.

2. The fluorocarbon coating for aluminum ceiling surfaces according to claim 1, characterized in that, In step S1, the mass ratio of nano-titanium dioxide to Tris-HCl buffer is 1:10-12; the concentration of dopamine in Tris-HCl buffer is 2-3 mg / mL.

3. The fluorocarbon coating for aluminum ceiling surfaces according to claim 1, characterized in that, The Tris-HCl buffer solution described in step S1 has a pH of 8.5-8.6 and a concentration of 10-15 mmol / L.

4. The fluorocarbon coating for aluminum ceiling surfaces according to claim 1, characterized in that, In step S2, the mass ratio of polydopamine-nano titanium dioxide, 2-chloro-5-cyanobenzimidazole, and triethylamine is 1:0.3-0.4:0.2-0.

3.

5. A fluorocarbon coating for aluminum ceiling surfaces according to claim 1, characterized in that, The molar ratio of triphenylphosphine to 3-chloropropyltrimethoxysilane is 1:1-1.

1.

6. A fluorocarbon coating for aluminum ceiling surfaces according to claim 1, characterized in that, The dispersant is any one or a mixture of several of BYK-110, BYK-161, and BYK-192.

7. A fluorocarbon coating for aluminum ceiling surfaces according to claim 1, characterized in that, The leveling agent is any one or a mixture of several of EFKA-3777, EFKA-3030, and AKN-1377.

8. A fluorocarbon coating for aluminum ceiling surfaces according to claim 1, characterized in that, The defoamer is an organosilicon defoamer; the curing agent is an HDI trimer curing agent.

9. A method for preparing a fluorocarbon coating for aluminum ceiling surfaces as described in any one of claims 1-8, characterized in that, The process includes the following steps: according to the weight ratio, water-based fluorocarbon resin, modified nano titanium dioxide, modified silane, dispersant, leveling agent, defoamer and deionized water are mixed evenly to obtain component A; then component A and component B are mixed evenly to obtain a fluorocarbon coating for aluminum ceiling surfaces.

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