High-weatherability water-based fluorocarbon coating and preparation method thereof

Abstract

The present application relates to the technical field of paint, in particular to a kind of high weatherability water-based fluorocarbon paint and preparation method thereof, component A in the present application includes the following mass parts raw materials: water-based fluorocarbon resin 46-62 parts;Deionized water 4.5-13 parts;Color filler 10-18 parts;Inorganic nanoparticle composition 4.7-6.5 parts;Antioxidant 0.6-0.8 parts;Leveling agent 0.4-0.6 parts;Dispersant 0.4-0.6 parts;Wherein, the dynamic reversible covalent bond contained in the surface of modified zirconium dioxide is played through fracture and recondensation, and the synergistic effect of inorganic nanoparticle recompounding is effectively improved the weather resistance of paint;The modified curing agent in component B introduces the tertiary aliphatic cyclic structure and fluorine-containing group into the isocyanate curing agent matrix, improves the intermolecular compatibility, and also further improves the weather resistance of paint after mixing with solvent-free water-based isocyanate curing agent, with wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coating technology, and in particular to a high-weatherability water-based fluorocarbon coating and a preparation method thereof. BACKGROUND

[0002] The corrosion resistance of fluorocarbon coating itself is very strong, and fluorocarbon paint, as a matching topcoat for heavy-duty corrosion protection, can be used for outdoor corrosion protection matching of ships, port facilities, bridges, steel structures, oil drilling platforms, storage facilities and chemical equipment, as well as outdoor decoration corrosion protection of engineering vehicles and equipment. At the same time, as one of the types of environmentally friendly products specified by the state, water-based paint has the absolute advantages of low VOC content, no strong irritating odor and environmental friendliness, and has become the main character in the current paint market. Water-based fluorocarbon paint is born in such an environment.

[0003] Water-based fluorocarbon paint uses water-based fluorocarbon emulsion as a film-forming material and belongs to a kind of high-weatherability protective coating with high film hardness, good stain resistance and low VOC content. It is more environmentally friendly than oil-based fluorocarbon paint and is also an environmentally friendly and healthy coating. Water-based fluorocarbon paint is a water-based coating, and its main components include resin, pigment and filler, filler, and additives. Among them, resin is one of the main components of water-based fluorocarbon paint, which determines the weather resistance, chemical resistance, and adhesion of water-based fluorocarbon paint. Common water-based fluorocarbon paint resins include FEVE fluorocarbon emulsion, PVDF fluorocarbon emulsion, fluorine-modified polyurethane resin or acrylic resin emulsion, etc. Pigment and filler are components that play a coloring role in water-based fluorocarbon paint and can meet the different needs of customers through different colors. Filler mainly plays the role of filling and increasing the thickness of the coating film. Additives can adjust the rheological property, consistency, and drying time of the coating.

[0004] In the prior art, patent technical document CN111019472A discloses a kind of concrete single-component water-based fluorocarbon coating, including the following weight percentage components: deionized water 10%-15%, PH regulator 0.1%-0.5%, dispersant 0.2%-1%, wetting agent 0.1%-0.5%, defoamer 0.1%-0.5%, titanium white 15%-25%, heavy calcium 5%-15%, calcined kaolin 5%-15%, antifreeze 2%-5%, single-component fluorocarbon emulsion 40%-50%, film-forming additive 2%-8%, bactericide 0.1%-0.3%, mildewcide 0.1%-0.3%, thickening agent 0.1%-0.5%, anti-settling agent 0.1%-0.5%; The single-component formula contained in the invention is convenient to use and has low VOC environmental protection, but its weather resistance needs to be further improved.

[0005] Therefore, according to the related technology in the above, it is urgent to develop a high-weatherability water-based fluorocarbon coating and a preparation method thereof. SUMMARY

[0006] Therefore, the present application aims to provide a high-weatherability water-based fluorocarbon coating and a preparation method thereof to solve the problem of poor weatherability of water-based coatings in the prior art.

[0007] Based on the above purpose, the present application provides a high-weatherability water-based fluorocarbon coating and a preparation method thereof.

[0008] A high-weatherability water-based fluorocarbon coating comprises component A and component B.

[0009] The component A comprises the following raw materials by mass fraction:

[0010] The water-based fluorocarbon resin is 46-62 parts; deionized water is 4.5-13 parts; pigment and filler is 10-18 parts; inorganic nano-particle composition is 4.7-6.5 parts; antioxidant is 0.6-0.8 parts; leveling agent is 0.4-0.6 parts; and dispersant is 0.4-0.6 parts.

[0011] The component B comprises the following raw materials by mass fraction:

[0012] The solvent-free water-based isocyanate curing agent is 8-12 parts; the modified curing agent is 1.7-2.9 parts; and poloxamer 123 is 0.05-0.1 parts.

[0013] The water-based fluorocarbon resin has a fluorine content greater than 15% and a hydroxyl content of 2wt%-4wt%;

[0014] The inorganic nano-particle composition is obtained by mixing modified zirconium dioxide, modified silicon dioxide and pretreated carbon nanotubes at a mass ratio of 18.6-23.1:6.9-8.5:6.9-8.5.

[0015] The solvent-free water-based isocyanate curing agent is HDI hydrophilic trimer, and the viscosity at 25℃ is ≤2500mPa·s.

[0016] The modified curing agent is prepared from hydrogenated rosin alcohol, perfluorooctanol, hexamethylene diisocyanate and dibutyltin dilaurate.

[0017] The hydrogenated rosin alcohol has a hydroxyl value of 145-160mgKOH / g.

[0018] Preferably, the preparation method of the modified curing agent is as follows:

[0019] In a nitrogen atmosphere, hydrogenated rosin alcohol and perfluorooctanol are added to a four-necked flask, and n-hexane is added. The temperature is raised to 48-58℃, and after stirring and incubation for 30-50min, the temperature is lowered to 40-45℃. Dibutyltin dilaurate is added, and after stirring for 10-20min, hexamethylene diisocyanate is added dropwise to the system. After the dropwise addition is completed, heating reaction is carried out. After the reaction is completed, vacuum distillation is carried out to obtain the modified curing agent.

[0020] Preferably, the hydrogenated rosin alcohol, perfluorooctanol, n-hexane, dibutyltin dilaurate and hexamethylene diisocyanate are used in a ratio of 2.65-5.3g:0.28-0.57g:25-38mL:0.004-0.0063g:0.82-1.47g;

[0021] The temperature during the heating reaction is 72-78℃, and the time is 2.5-3h.

[0022] Preferably, the modified zirconium dioxide is prepared as follows:

[0023] Tetrapropyl zirconate is added dropwise into glacial acetic acid, and deionized water is added at a stirring speed of 180-230rpm. Then 3-aminopropyl triethoxysilane is added, and stirring is performed at room temperature for 22-24h to obtain the modified zirconium dioxide.

[0024] Preferably, the tetrapropyl zirconate, glacial acetic acid, deionized water and 3-aminopropyl triethoxysilane are used in a ratio of 1.3-1.8g:0.45-0.65g:32-45mL:1.02-1.26g.

[0025] Preferably, the pretreated carbon nanotube is prepared as follows:

[0026] The carbon nanotube raw material is added into mixed acid solution, and ultrasonic treatment is performed at 40-50℃ for 6-8h. After cooling and standing for a period of time, dilution, suction filtration and water washing are performed, and then vacuum drying is performed to obtain the pretreated carbon nanotube.

[0027] The carbon nanotube raw material is multi-walled carbon nanotube with a diameter of 10-20nm and a length of 1-10μm.

[0028] The mixed acid solution is obtained by mixing 70% nitric acid and 98% concentrated sulfuric acid in a volume ratio of 1:3-5.

[0029] Preferably, the modified silica is prepared as follows:

[0030] Heptadecafluorodecyltrimethoxysilane and a first ethanol aqueous solution are added into a three-necked flask, and acetic acid is added dropwise to adjust the pH of the solution to 3-4. Hydrolysis is performed at room temperature for 1-1.5h. Fumed nano-silica is added into a second ethanol aqueous solution, and ultrasonic dispersion is performed for 30-40min. Then the fumed nano-silica is added into the three-necked flask, and heating reaction is performed. After the reaction is completed, rotary evaporation and vacuum drying are performed to obtain the modified silica.

[0031] The heptadecafluorodecyltrimethoxysilane and the first ethanol aqueous solution are used in a ratio of 4.56-5.2g:100-120mL.

[0032] Preferably, the volume ratio of ethanol and deionized water in the first ethanol aqueous solution is 8-9:1-2;

[0033] The volume ratio of ethanol and deionized water in the second ethanol aqueous solution is 8-9:1-2;

[0034] The usage ratio of the fumed nanosilica and the second ethanol aqueous solution is 15.1-16.7g:500-600mL;

[0035] The particle size of the fumed nanosilica is 15-25nm;

[0036] The temperature during the heating reaction is 45-53℃, and the time is 6-6.5h.

[0037] Preferably, the dispersant is at least one of dispersant BYK190, dispersant BYK194N, dispersant BYK2015, dispersant TEGO747W and dispersant TEGO760W;

[0038] The leveling agent is an acrylate leveling agent, and the glass transition temperature is 5052℃;

[0039] The antioxidant is hindered phenolic antioxidant 1010.

[0040] A preparation method of a high-weatherability water-based fluorocarbon paint, comprising the following steps:

[0041] Step S1. Mix deionized water, a dispersant and a leveling agent uniformly, then add a pigment filler and an inorganic nanoparticle composition, mix uniformly, then add a water-based fluorocarbon resin and an antioxidant, stir at a stirring speed of 500-650rpm for 20-30min, to obtain component A;

[0042] Step S2. Mix a solvent-free water-based isocyanate curing agent, a modified curing agent and poloxamer 123 uniformly to obtain component B, and when used, add component B to component A, stir uniformly and then perform construction, to obtain the high-weatherability water-based fluorocarbon paint.

[0043] The beneficial effects of the present application are as follows:

[0044] The application provides a high-weatherability water-based fluorocarbon paint and a preparation method thereof, and the high-weatherability water-based fluorocarbon paint is obtained by mixing component A and component B; in the inorganic nanoparticle composition, amino silane modified tetrapropyl zirconate is used to form a dynamic reversible covalent bond on the surface of the nanoparticles through a condensation hydrolysis reaction, the stress concentration of the water-based fluorocarbon paint is effectively relieved and the crack propagation is delayed through the breaking and recondensation of the covalent bond, and thus the weatherability is improved; the silicon hydroxyl contained on the surface of the modified silicon dioxide can form a hydrogen bond network with the zirconium hydroxyl in the modified zirconium dioxide, and the hydrogen bond network and the dynamic reversible covalent bond play a synergistic effect, so that the weatherability of the paint is improved; the pretreated carbon nanotube has excellent mechanical properties and ultraviolet absorption capacity, and the surface of the carbon nanotube is provided with active functional groups through the surface carboxylation pretreatment, so that the dynamic reversible covalent bond can be formed on the surface of the zirconium dioxide, and the weatherability of the paint is improved.

[0045] In the modified curing agent, the isocyanate groups in the hexamethylene diisocyanate and the hydroxyl groups in the hydrogenated rosin alcohol and the perfluorooctanol are subjected to nucleophilic addition under the action of a catalyst, and then the three-membered aliphatic cyclic structure in the hydrogenated rosin alcohol and the fluorine-containing group in the perfluorooctanol are introduced into the matrix, the three-membered aliphatic cyclic structure in the hydrogenated rosin alcohol can effectively improve the adhesion and weatherability of the water-based fluorocarbon paint, and the fluorine-containing group in the perfluorooctanol reduces the polarity of the modified curing agent, reduces the polarity difference between the fluorocarbon resin and the modified curing agent, and thus enhances the compatibility between the molecules, avoids microphase separation during the film forming process, and greatly improves the weatherability of the water-based fluorocarbon paint after being mixed with the solvent-free water-based isocyanate curing agent, and compared with the prior art, has a wide application prospect. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the application clearer, the application is further described in detail below with reference to specific examples.

[0047] The sources and properties of some raw materials used in the application are as follows:

[0048] The tetrapropyl zirconate is purchased from Fosman Technology (Beijing) Co., Ltd., the hydrogenated rosin alcohol is purchased from Eastman Company, and the hexamethylene diisocyanate is purchased from BASF (China) Co., Ltd.

[0049] Example 1: A preparation method of a high-weatherability water-based fluorocarbon paint, comprising the following steps:

[0050] S1. Under a nitrogen atmosphere, 2.65 g of hydrogenated rosin alcohol with a hydroxyl value of 145 mgKOH / g and 0.28 g of perfluoro octanol were added to a four-necked flask, 25 mL of n-hexane was added, and the temperature was raised to 48℃, stirred and kept for 30 min, then cooled to 40℃, 0.004 g of dibutyl tin dilaurate was added, stirred for 10 min, then 0.82 g of hexamethylene diisocyanate was added dropwise, after the addition was completed, the reaction was heated at 72℃ for 2.5 h, after the reaction was completed, vacuum distillation was carried out, and a modified curing agent was obtained;

[0051] S2. 1.3 g of tetrapropyl zirconate was added dropwise into 0.45 g of glacial acetic acid, and then added into 32 mL of deionized water under the stirring speed of 180 rpm, and then 1.02 g of 3-aminopropyl triethoxysilane was added, and stirred at room temperature for 22 h to obtain a modified zirconia;

[0052] S3. The carbon nanotube raw material was added to the mixed acid solution, and ultrasonic treatment was carried out at 40℃ for 6h, wherein the mixed acid solution was obtained by mixing 70% by mass nitric acid and 98% by mass concentrated sulfuric acid in a volume ratio of 1:3, then after standing for a period of time, dilution, suction filtration and water washing to neutral, vacuum drying was carried out, and pretreated carbon nanotubes were obtained;

[0053] S4. 4.56 g of heptadecafluorodecyltrimethoxysilane and 100 mL of ethanol aqueous solution were added to a three-necked flask, wherein the volume ratio of ethanol and deionized water in the ethanol aqueous solution was 8:2, and acetic acid was added dropwise to adjust the solution pH to 3, and hydrolysis was carried out at room temperature for 1 h, 15.1 g of fumed nano-silica was added to 500 mL of ethanol aqueous solution, ultrasonic dispersion was carried out for 30 min, and then added to the three-necked flask, and heated at 45℃ for 6 h, after the reaction was completed, rotary evaporation and vacuum drying were carried out, and modified silica was obtained;

[0054] S5. 18.6 g of modified zirconia, 6.9 g of modified silica and 6.9 g of pretreated carbon nanotubes were mixed to obtain an inorganic nanoparticle composition, 4.5 g of deionized water, 0.4 g of dispersant BYK190 and 0.4 g of acrylate leveling agent were uniformly mixed, then 10 g of pigment and filler and 4.7 g of inorganic nanoparticle composition were added, and after uniform mixing, 46 g of water-based fluorocarbon resin and 0.6 g of hindered phenolic antioxidant 1010 were added, and stirred at a stirring speed of 500 rpm for 20 min to obtain component A;

[0055] S6. 8 g of solvent-free water-based isocyanate curing agent, 1.7 g of modified curing agent and 0.05 g of poloxamer 123 were uniformly mixed to obtain component B, and when used, component B was added to component A, stirred uniformly and applied, and a high-weatherability water-based fluorocarbon paint was obtained.

[0056] Embodiment 2: A preparation method of a high-weatherability waterborne fluorocarbon coating, comprising the following steps:

[0057] S1. In a nitrogen atmosphere, 3.55 g of hydrogenated rosin alcohol with a hydroxyl value of 150 mgKOH / g and 0.38 g of perfluorooctanol were added to a four-necked flask, 30 mL of n-hexane was added, and the temperature was raised to 50°C. After stirring and incubation for 38 min, the temperature was lowered to 42°C, 0.0047 g of dibutyltin dilaurate was added, and after stirring for 15 min, 1.02 g of hexamethylene diisocyanate was added dropwise to the system. After the dropwise addition was completed, the reaction was heated at 74°C for 2.5 h. After the reaction was completed, vacuum distillation was performed to obtain a modified curing agent;

[0058] S2. 1.5 g of tetrapropyl zirconate was added dropwise into 0.55 g of glacial acetic acid, and then added into 36 mL of deionized water under the stirring speed of 200 rpm. Then, 1.1 g of 3-aminopropyl triethoxysilane was added into the mixture. The mixture was stirred at room temperature for 23 h to obtain a modified zirconia;

[0059] S3. The carbon nanotube raw material was added into a mixed acid solution, and ultrasonic treatment was performed at 45°C for 7 h. The mixed acid solution was obtained by mixing 70% nitric acid and 98% concentrated sulfuric acid in a volume ratio of 1:4. After standing for a period of time, the solution was diluted, filtered, and washed with water to neutralize. Then, vacuum drying was performed to obtain pretreated carbon nanotubes;

[0060] S4. 4.8 g of heptadecafluorodecyltrimethoxysilane and 110 mL of an ethanol aqueous solution were added into a three-necked flask. The volume ratio of ethanol and deionized water in the ethanol aqueous solution was 8:2. Acetic acid was added to adjust the pH of the solution to 3. The solution was hydrolyzed at room temperature for 1 h. 15.6 g of fumed nano-silica was added into 540 mL of an ethanol aqueous solution, and ultrasonic dispersion was performed for 35 min. Then, the solution was added into the three-necked flask, and heated at 48°C for 6 h. After the reaction was completed, rotary evaporation and vacuum drying were performed to obtain modified silica;

[0061] S5. 20.1 g of modified zirconia, 7.5 g of modified silica, and 7.5 g of pretreated carbon nanotubes were mixed to obtain an inorganic nanoparticle composition. 7.5 g of deionized water, 0.48 g of dispersant BYK190, and 0.48 g of acrylate leveling agent were uniformly mixed. Then, 13 g of pigment and filler and 5.3 g of inorganic nanoparticle composition were added and uniformly mixed. Finally, 51 g of waterborne fluorocarbon resin and 0.68 g of hindered phenolic antioxidant 1010 were added. The mixture was stirred at a stirring speed of 550 rpm for 25 min to obtain component A;

[0062] S6. 9.5 g of solvent-free waterborne isocyanate curing agent, 2.1 g of modified curing agent and 0.07 g of poloxamer 123 were mixed uniformly to obtain component B. When used, component B was added to component A, stirred uniformly and applied, thereby obtaining the high-weatherability waterborne fluorocarbon coating.

[0063] Example 3: A preparation method of a high-weatherability waterborne fluorocarbon coating, comprising the following steps:

[0064] S1. In a nitrogen atmosphere, 4.4 g of hydrogenated rosin alcohol with a hydroxyl value of 155 mgKOH / g and 0.47 g of perfluorooctanol were added to a four-necked flask, 34 mL of n-hexane was added, and the temperature was raised to 55°C. After stirring and incubation for 40 min, the temperature was lowered to 43°C, 0.0052 g of dibutyltin dilaurate was added, and after stirring for 15 min, 1.22 g of hexamethylene diisocyanate was added dropwise to the system. After the dropwise addition was completed, the reaction was heated at 76°C for 3 h. After the reaction was completed, vacuum distillation was performed to obtain a modified curing agent;

[0065] S2. 1.65 g of tetrapropyl zirconate was added dropwise to 0.56 g of glacial acetic acid, and then added to 40 mL of deionized water under stirring at a speed of 210 rpm. Then, 1.18 g of 3-aminopropyl triethoxysilane was added thereto, and stirred at room temperature for 23 h to obtain a modified zirconia;

[0066] S3. The carbon nanotube raw material was added to a mixed acid solution, and ultrasonic treatment was performed at 45°C for 7 h. The mixed acid solution was obtained by mixing 70% nitric acid and 98% concentrated sulfuric acid in a volume ratio of 1:4. After standing for a period of time, the pretreated carbon nanotube was obtained by dilution, suction filtration, water washing and neutralization, and vacuum drying.

[0067] S4. 5 g of heptadecafluorodecyltrimethoxysilane and 110 mL of an ethanol aqueous solution were added to a three-necked flask, wherein the volume ratio of ethanol to deionized water in the ethanol aqueous solution was 9:1, and acetic acid was added dropwise to adjust the pH of the solution to 4. The solution was hydrolyzed at room temperature for 1.5 h. 16.1 g of fumed nano-silica was added to 570 mL of an ethanol aqueous solution, ultrasonic dispersion was performed for 35 min, and then added to the three-necked flask. The reaction was heated at 50°C for 6.5 h. After the reaction was completed, rotary evaporation and vacuum drying were performed to obtain modified silica.

[0068] S5. 21.1 g of modified zirconium dioxide, 8 g of modified silicon dioxide and 8 g of pretreated carbon nanotubes were mixed to obtain an inorganic nanoparticle composition, 10.5 g of deionized water, 0.53 g of dispersant BYK190 and 0.53 g of acrylate leveling agent were uniformly mixed, then 16 g of pigment and filler and 5.9 g of inorganic nanoparticle composition were added, after uniform mixing, 58 g of water-based fluorocarbon resin and 0.73 g of hindered phenolic antioxidant 1010 were added, and stirring was carried out at a stirring speed of 600 rpm for 25 min to obtain component A;

[0069] S6. After 10 g of solvent-free water-based isocyanate curing agent, 2.4 g of modified curing agent and 0.09 g of poloxamer 123 were uniformly mixed, component B was obtained. When used, component B is added to component A, stirred uniformly and applied to obtain a high-weatherability water-based fluorocarbon coating.

[0070] Example 4: A preparation method of a high-weatherability water-based fluorocarbon coating, comprising the following steps:

[0071] S1. In a nitrogen atmosphere, 5.3 g of hydrogenated rosin alcohol with a hydroxyl value of 160 mgKOH / g and 0.57 g of perfluoro octanol were added to a four-necked flask, and 38 mL of n-hexane was added. The temperature was raised to 58℃, and after stirring and incubation for 50 min, the temperature was lowered to 45℃, 0.0063 g of dibutyltin dilaurate was added, and after stirring for 20 min, 1.47 g of hexamethylene diisocyanate was added dropwise to the system. After the dropwise addition was completed, the reaction was heated at 78℃ for 3h. After the reaction was completed, vacuum distillation was carried out to obtain a modified curing agent;

[0072] S2. 1.8 g of zirconium acid tetrapropyl ester was added dropwise into 0.65 g of glacial acetic acid, and then 45 mL of deionized water was added under stirring at a speed of 230 rpm. Then 1.26 g of 3-aminopropyl triethoxysilane was added, and the mixture was stirred at room temperature for 24 h to obtain modified zirconium dioxide;

[0073] S3. The carbon nanotube raw material was added to the mixed acid solution, and ultrasonic treatment was carried out at 50℃ for 8h. The mixed acid solution was obtained by mixing 70% nitric acid and 98% concentrated sulfuric acid in a volume ratio of 1:5. After standing for a period of time, the pretreated carbon nanotubes were obtained by dilution, suction filtration, water washing and neutralization, and then vacuum drying.

[0074] S4. 5.2 g of heptadecafluorodecyltrimethoxysilane and 120 mL of an ethanol aqueous solution were added into a three-necked flask, wherein the volume ratio of ethanol and deionized water in the ethanol aqueous solution was 9:1, and acetic acid was added dropwise to adjust the pH of the solution to 4, and hydrolysis was performed at room temperature for 1.5 h, 16.7 g of fumed nano-silica was added into 600 mL of an ethanol aqueous solution, and ultrasonic dispersion was performed for 40 min, and then the fumed nano-silica was added into the three-necked flask, and heating reaction was performed at 53°C for 6.5 h, after the reaction was completed, rotary evaporation and vacuum drying were performed, and modified silica was obtained;

[0075] S5. 23.1 g of modified zirconium dioxide, 8.5 g of modified silica, and 8.5 g of pretreated carbon nanotubes were mixed to obtain an inorganic nanoparticle composition, 13 g of deionized water, 0.6 g of dispersant BYK190, and 0.6 g of acrylate leveling agent were uniformly mixed, 18 g of pigments and fillers and 6.5 g of the inorganic nanoparticle composition were added, and after uniform mixing, 62 g of water-based fluorocarbon resin and 0.8 g of hindered phenolic antioxidant 1010 were added, and stirring was performed at a stirring speed of 650 rpm for 30 min to obtain component A;

[0076] S6. Component B was obtained by uniformly mixing 12 g of a solvent-free water-based isocyanate curing agent, 2.9 g of a modified curing agent, and 0.1 g of poloxamer 123, and when used, component B was added to component A, and uniform stirring was performed to obtain the high-weatherability water-based fluorocarbon coating.

[0077] Comparative Example 1:

[0078] In this comparative example, perfluorooctanol was not added in the preparation process of the modified curing agent compared with Example 1, and the remaining steps and parameters were the same, and this comparative example will not be repeated, and finally a water-based fluorocarbon coating was obtained.

[0079] Comparative Example 2:

[0080] In this comparative example, hydrogenated rosin alcohol was not added in the preparation process of the modified curing agent compared with Example 1, and the remaining steps and parameters were the same, and this comparative example will not be repeated, and finally a water-based fluorocarbon coating was obtained.

[0081] Comparative Example 3:

[0082] In this comparative example, inorganic nanoparticle composition was not added in the preparation process of the water-based fluorocarbon coating compared with Example 1, and the remaining steps and parameters were the same, and this comparative example will not be repeated, and finally a water-based fluorocarbon coating was obtained.

[0083] Comparative Example 4:

[0084] In this comparative example, only “component B” was replaced with “solvent-free water-based isocyanate curing agent” compared with Example 1, and the remaining steps and parameters were the same, and this comparative example will not be repeated, and finally a water-based fluorocarbon coating was obtained.

[0085] Comparative Example 5:

[0086] The comparative example is compared with Example 1 only by replacing the "inorganic nanoparticle composition" with "modified silica", and the rest of the steps and parameters are the same. The comparative example is not repeated here. Finally, the water-based fluorocarbon coating is obtained.

[0087] Comparative Example 6:

[0088] The comparative example is compared with Example 1 only by replacing the "inorganic nanoparticle composition" with "modified zirconium dioxide", and the rest of the steps and parameters are the same. The comparative example is not repeated here. Finally, the water-based fluorocarbon coating is obtained.

[0089] Comparative Example 7:

[0090] The comparative example is compared with Example 1 only by replacing the "inorganic nanoparticle composition" with "pretreated carbon nanotubes", and the rest of the steps and parameters are the same. The comparative example is not repeated here. Finally, the water-based fluorocarbon coating is obtained.

[0091] Comparative Example 8:

[0092] The comparative example is compared with Example 1 only by replacing "18.6g modified zirconium dioxide, 6.9g modified silica and 6.9g pretreated carbon nanotubes" with "6.9g modified zirconium dioxide, 6.9g modified silica and 6.9g pretreated carbon nanotubes", and the rest of the steps and parameters are the same. The comparative example is not repeated here. Finally, the water-based fluorocarbon coating is obtained.

[0093] Comparative Example 9:

[0094] The comparative example is compared with Example 1 only by replacing the "pretreated carbon nanotubes" with "carbon nanotubes", and the rest of the steps and parameters are the same. The comparative example is not repeated here. Finally, the water-based fluorocarbon coating is obtained.

[0095] Performance test:

[0096] The artificial climate accelerated test is tested according to the "exposure cycle type 7" in the appendix of GB / T14522-2008, the test time is 3000h, and the light loss rate is calculated;

[0097] The liquid medium test is tested according to GB / T9274-1998, and whether the fluorocarbon coating layer formed by the water-based fluorocarbon coating prepared by Example 1-Example 4 and Comparative Example 1-Comparative Example 10 appears blistering and rusting and other pathological conditions is observed;

[0098] The pencil hardness is tested according to GB / T6739;

[0099] The gloss is tested according to GB / T9754.

[0100] Table 1

[0101]

[0102] Data analysis:

[0103] As can be seen from Table 1, the water-based fluorocarbon paint prepared by the application has better weather resistance, high hardness and good gloss, which may be due to the fact that in the inorganic nanoparticle composition, the amino silane modified zirconium acid tetrapropyl ester forms a dynamic reversible Zr-O-Si bond on the surface of the nanoparticles through condensation hydrolysis reaction, and through the breaking and recondensation of the Zr-O-Si bond, the stress concentration of the water-based fluorocarbon paint is effectively alleviated, the crack propagation is delayed, and the weather resistance is improved; when irradiated by ultraviolet light, the Zr-O-Si bond with lower bond energy absorbs ultraviolet light energy, the covalent bond breaks, and after absorbing a certain amount of energy to reach the activation energy required for condensation reaction, the covalent bond rehydrates and condenses, the cracks are healed, and the anti-ultraviolet aging and anti-cracking performance of the paint is improved; the silicon hydroxyl contained on the surface of the modified silicon dioxide can form a hydrogen bond network with the zirconium hydroxyl in the modified zirconium dioxide, and play a synergistic effect with the dynamic reversible Zr-O-Si bond to improve the weather resistance of the paint; the pretreated carbon nanotubes have excellent mechanical properties and ultraviolet absorption capacity, can effectively disperse and absorb ultraviolet energy, reduce the direct damage of ultraviolet to the fluorocarbon resin, improve the anti-ultraviolet performance of the paint, and through the surface carboxylation pretreatment of the carbon nanotubes, active functional groups are formed on the surface, which can form a dynamic reversible Zr-O-C bond with the surface of the zirconium dioxide, and the weather resistance of the paint is further improved; in the modified curing agent, the isocyanate groups in hexamethylene diisocyanate and the hydroxyl groups in hydrogenated rosin alcohol and perfluorooctanol undergo nucleophilic addition under the action of a catalyst, and then the three-membered aliphatic cyclic structure in the hydrogenated rosin alcohol and the fluorine-containing group in the perfluorooctanol are introduced into the matrix, the three-membered aliphatic cyclic structure in the hydrogenated rosin alcohol can effectively improve the adhesion and weather resistance of the water-based fluorocarbon paint, and the fluorine-containing group in the perfluorooctanol reduces the polarity of the modified curing agent, reduces the polarity difference between the fluorocarbon resin and the modified curing agent, and thus enhances the compatibility between the molecules, avoids microphase separation during film formation, and greatly improves the weather resistance of the water-based fluorocarbon paint after mixing with the solvent-free water-based isocyanate curing agent.

[0104] Those skilled in the art will understand that the discussion of any of the above embodiments is merely exemplary and is not intended to suggest that the scope of the application is limited to these examples; under the idea of the application, the above embodiments or technical features in different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the application as described above, which are not provided in detail for the sake of brevity.

[0105] The present application is intended to cover all such alternatives, modifications, and variations of the application falling within the broad scope of the appended claims. Accordingly, any and all such alternatives, modifications, equivalents, improvements and the like are intended to be encompassed by the present application.

Claims

1. A high weather resistance water-based fluorocarbon paint, characterized by, The component A and the component B are included; The component A includes the following mass parts of raw materials: Water-based fluorocarbon resin 46-62 parts; deionized water 4.5-13 parts; pigment and filler 10-18 parts; inorganic nano-particle composition 4.7-6.5 parts; antioxidant 0.6-0.8 parts; leveling agent 0.4-0.6 parts; dispersant 0.4-0.6 parts; The component B includes the following mass parts of raw materials: Solvent-free water-based isocyanate curing agent 8-12 parts; Modified curing agent 1.7-2.9 parts; poloxamer 123 0.05-0.1 parts; The water-based fluorocarbon resin has a fluorine content greater than 15% and a hydroxyl content of 2wt%-4wt%; The inorganic nano-particle composition is obtained by mixing modified zirconium dioxide, modified silicon dioxide and pretreated carbon nanotubes at a mass ratio of 18.6-23.1:6.9-8.5:6.9-8.5; The solvent-free water-based isocyanate curing agent is an HDI hydrophilic trimer, and has a viscosity of ≤2500 mPa·s at 25℃; The modified curing agent is prepared from hydrogenated rosin alcohol, perfluorooctanol, hexamethylene diisocyanate and dibutyltin dilaurate; The hydrogenated rosin alcohol has a hydroxyl value of 145-160 mgKOH / g.

2. The high weather resistant water-based fluorocarbon paint according to claim 1, characterized by, The preparation method of the modified curing agent is as follows: In a nitrogen atmosphere, hydrogenated rosin alcohol and perfluorooctanol are added to a four-necked flask, and n-hexane is added. The temperature is raised to 48-58℃, and after stirring and incubation for 30-50 min, the temperature is lowered to 40-45℃. Dibutyltin dilaurate is added, and after stirring for 10-20 min, hexamethylene diisocyanate is added dropwise to the system. After the dropwise addition is completed, heating reaction is carried out. After the reaction is completed, vacuum distillation is carried out to obtain the modified curing agent.

3. The high weather resistant water-based fluorocarbon paint according to claim 2, characterized by, The amount ratio of the hydrogenated rosin alcohol, perfluorooctanol, n-hexane, dibutyltin dilaurate and hexamethylene diisocyanate is 2.65-5.3 g:0.28-0.57 g:25-38 mL:0.004-0.0063 g:0.82-1.47 g; The temperature of the heating reaction is 72-78℃, and the time is 2.5-3 h.

4. The high weather resistant water-based fluorocarbon paint according to claim 1, characterized by, The preparation method of the modified zirconium dioxide is as follows: Tetrapropyl zirconate is added dropwise to glacial acetic acid, and deionized water is added at a stirring speed of 180-230 rpm. 3-Aminopropyl triethoxysilane is then added, and the mixture is stirred at room temperature for 22-24 h to obtain the modified zirconium dioxide.

5. The high-weather-resistant water-based fluorocarbon paint according to claim 4, characterized by, The amount ratio of the tetrapropyl zirconate, glacial acetic acid, deionized water and 3-aminopropyl triethoxysilane is 1.3-1.8 g:0.45-0.65 g:32-45 mL:1.02-1.26 g.

6. The high weatherable waterborne fluorocarbon coating according to claim 1, wherein, The preparation method of the pretreated carbon nanotube is as follows: Carbon nanotube raw material is added to mixed acid solution, and ultrasonic treatment is carried out at 40-50℃ for 6-8 h. After cooling and standing for a period of time, the pretreated carbon nanotube is obtained by dilution, suction filtration and water washing, and then vacuum drying. The carbon nanotube raw material is multi-walled carbon nanotube with a diameter of 10-20 nm and a length of 1-10 μm. The mixed acid solution is obtained by mixing nitric acid with a mass fraction of 70% and concentrated sulfuric acid with a mass fraction of 98% at a volume ratio of 1:3-5.

7. The high weatherable waterborne fluorocarbon coating according to claim 1, wherein, The preparation method of the modified silica is as follows: The heptadecafluorodecyltrimethoxysilane and the first ethanol aqueous solution are added into a three-necked flask, acetic acid is added dropwise to adjust the pH of the solution to 3-4, hydrolysis is carried out at room temperature for 1-1.5 h, the fumed nano-silica is added into the second ethanol aqueous solution, ultrasonic dispersion is carried out for 30-40 min, then the fumed nano-silica is added into the three-necked flask, and heating reaction is carried out, after the reaction is completed, rotary evaporation and vacuum drying are carried out, and the modified silica is obtained; The heptadecafluorodecyltrimethoxysilane and the first ethanol aqueous solution are added into a three-necked flask, acetic acid is added dropwise to adjust the pH of the solution to 3-4, hydrolysis is carried out at room temperature for 1-1.5 h, the fumed nano-silica is added into the second ethanol aqueous solution, ultrasonic dispersion is carried out for 30-40 min, then the fumed nano-silica is added into the three-necked flask, and heating reaction is carried out, after the reaction is completed, rotary evaporation and vacuum drying are carried out, and the modified silica is obtained; 8.The high-weather-resistant water-based fluorocarbon paint of claim 7, wherein, The volume ratio of ethanol to deionized water in the first ethanol aqueous solution is 8-9:1-2; The volume ratio of ethanol to deionized water in the second ethanol aqueous solution is 8-9:1-2; The volume ratio of the fumed nano-silica to the second ethanol aqueous solution is 15.1-16.7 g:500-600 mL; The particle size of the fumed nano-silica is 15-25 nm; The temperature of the heating reaction is 45-53℃, and the time is 6-6.5 h. 9.The high-weather-resistant water-based fluorocarbon paint of claim 1, wherein, The dispersant is at least one of dispersant BYK190, dispersant BYK194N, dispersant BYK2015, dispersant TEGO747W and dispersant TEGO760W; The leveling agent is an acrylate leveling agent, and the glass transition temperature is 5052℃; The antioxidant is hindered phenolic antioxidant 1010.

10. The method for preparing a high weather-resistant waterborne fluorocarbon coating according to any one of claims 1-9, characterized in that, The method comprises the following steps: Step S1. Deionized water, a dispersant and a leveling agent are uniformly mixed, then fillers and inorganic nanoparticles are added and uniformly mixed, then water-based fluorocarbon resin and an antioxidant are added, stirring is carried out at a stirring speed of 500-650 rpm for 20-30 min, and component A is obtained; Step S2. A solvent-free water-based isocyanate curing agent, a modified curing agent and poloxamer 123 are uniformly mixed, and component B is obtained, in use, component B is added to component A, stirring is uniformly carried out, and a high-weatherability water-based fluorocarbon coating is obtained.

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