Weather-resistant water-based vehicle body paint and preparation method thereof

Abstract

The present invention discloses a weather-resistant water-based vehicle body paint and a preparation method thereof, and relates to the technical field of coatings. The weather-resistant water-based vehicle body paint of the present invention comprises, by weight, 100 parts by weight of component A, 10 to 13 parts by weight of component B, and 6 to 12 parts by weight of component C; component A comprises, by weight, 15 to 20 parts by weight of water, 35 to 40 parts by weight of weather-resistant acrylic copolymer, 1.4 to 1.6 parts by weight of dispersant, 0.08 to 0.1 parts by weight of defoamer, 9 to 11 parts by weight of anti-rust pigment, 1 to 3 parts by weight of carbon black powder, 7 to 9 parts by weight of 800-mesh sericite powder, and 11 to 13 parts by weight of modified talc, 0.15-0.2 parts by weight of wetting agent, 1.5-2 parts by weight of catalyst, 0.3-0.35 parts by weight of thickener, 3-3.5 parts by weight of co-solvent ethylene glycol monobutyl ether; component B includes, by weight: 95-98 parts by weight of aqueous epoxy emulsion, 2-2.5 parts by weight of film-forming aid dipropylene glycol butyl ether, 2-5 parts by weight of water, and 0.3 part by weight of ammonium persulfate; component C includes, by weight, 4-8 parts by weight of fluorosilicone and 2-4 parts by weight of water.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, in particular to a weather-resistant water-based vehicle body paint and a preparation method thereof. Background Art

[0002] With the development of the automotive industry and consumers' increasing demands for vehicle quality, body paint must not only offer aesthetically pleasing and decorative qualities but also exceptional durability. The quality of body paint directly impacts the vehicle's appearance, durability, and service life. Therefore, developing high-performance body paints, particularly those with excellent wear resistance, weather resistance, corrosion resistance, and adhesion properties, has become a key research area in the automotive industry.

[0003] Currently, the two main types of auto body paint commonly used in the market are solvent-based and water-based. While solvent-based auto body paint offers excellent coating performance, it contains large amounts of organic solvents, which not only pollute the environment but are also harmful to human health. In contrast, water-based auto body paint is gaining increasing attention and favor due to its low VOC (volatile organic compound) emissions, easy cleaning, and environmentally friendly characteristics. However, existing water-based auto body paints still have shortcomings in terms of wear resistance, weather resistance, and corrosion resistance. In particular, the paint surface is prone to wear, fading, and blistering when used in harsh environments for extended periods.

[0004] To overcome these challenges, researchers have been exploring ways to improve the formulation and preparation process of water-based auto body paints to enhance their overall performance. This involves selecting appropriate raw materials such as film-forming substances, pigments, fillers, and additives, and optimizing the ratios and preparation conditions of these components. For example, the introduction of polymers with specialized functions, nanomaterials, or other functional additives can significantly enhance the wear, weathering, and corrosion resistance of auto body paints. Furthermore, improving the adhesion between the substrate and the coating is also a key factor in improving the overall performance of auto body paints.

[0005] In view of this, the present invention aims to provide a new type of weather-resistant water-based car body paint and a preparation method thereof. By optimizing the formula design and process flow, the car body paint can be comprehensively improved in terms of wear resistance, weather resistance, corrosion resistance and adhesion, thereby meeting the demand of the modern automotive industry for high-quality car body paint. Summary of the Invention

[0006] The object of the present invention is to provide a weather-resistant water-based vehicle body paint and a preparation method thereof, so as to solve the problems existing in the prior art.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: A weather-resistant water-based car body paint, the raw material components include, by weight, 100 parts by weight of component A, 10-13 parts by weight of component B, and 6-12 parts by weight of component C; component A includes, by weight, 15-20 parts by weight of water, 35-40 parts by weight of weather-resistant acrylic copolymer, 1.4-1.6 parts by weight of dispersant, 0.08-0.1 parts by weight of defoamer, 9-11 parts by weight of anti-rust pigment, 1-3 parts by weight of carbon black powder, 7-9 parts by weight of 8 00 mesh sericite powder, 11-13 parts by mass of modified talc, 0.15-0.2 parts by mass of wetting agent, 1.5-2 parts by mass of catalyst, 0.3-0.35 parts by mass of thickener, 3-3.5 parts by mass of co-solvent ethylene glycol monobutyl ether; component B includes, by weight: 95-98 parts by mass of aqueous epoxy emulsion, 2-2.5 parts by mass of film-forming aid dipropylene glycol butyl ether, 2-5 parts by mass of water, 0.3 part by mass of ammonium persulfate; component C includes, by weight, 4-8 parts by mass of fluorosilicone and 2-4 parts by mass of water.

[0008] Furthermore, the weather-resistant acrylic copolymer is obtained by copolymerizing acrylic acid, N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyl triazine, methyl methacrylate, and hydroxyethyl acrylate.

[0009] Furthermore, the modified talc powder is allylglycine intercalated calcium aluminum hydrotalcite.

[0010] Furthermore, the D50 of the modified talc is 2-6 μm.

[0011] The present invention also provides a method for preparing a weather-resistant water-based vehicle body paint, comprising the following preparation steps:

[0012] (1) Mixing the raw materials according to the raw material components and proportions of claim 1;

[0013] (2) 15-20 parts by mass of water, 35-40 parts by mass of weather-resistant acrylic copolymer, 1.4-1.6 parts by mass of dispersant, 0.08-0.1 parts by mass of defoamer, 9-11 parts by mass of anti-rust pigment, 1-3 parts by mass of carbon black powder, 7-9 parts by mass of 800-mesh sericite powder, 11-13 parts by mass of modified talc powder, 0.15-0.2 parts by mass of wetting agent, 1.5-2 parts by mass of catalyst, 0.3-0.35 parts by mass of thickener, and 3-3.5 parts by mass of co-solvent ethylene glycol monobutyl ether were poured into a ball mill and dispersed for 6 hours, discharged, sealed and set aside to obtain component A;

[0014] (3) Mix 95-98 parts by mass of aqueous epoxy emulsion, 2-2.5 parts by mass of film-forming aid dipropylene glycol butyl ether, 2-5 parts by mass of water, and 0.3 parts by mass of ammonium persulfate, and stir at 100-200 rpm for 2-4 hours, discharge, seal, and set aside to obtain component B;

[0015] (4) Mixing 4 to 8 parts by mass of fluorosilicone and 2 to 4 parts by mass of water, discharging the mixture, sealing the mixture for standby use, and obtaining component C;

[0016] (5) 100 parts by mass of component A, 10 to 13 parts by mass of component B, and 6 to 12 parts by mass of component C are packaged separately and combined into a group to obtain a weather-resistant water-based vehicle body paint.

[0017] Furthermore, the preparation method of the weather-resistant acrylic copolymer is as follows: 0.5 parts by mass of acrylic acid, 2 to 6 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyltriazine, 14 parts by mass of methyl methacrylate, 18 parts by mass of hydroxyethyl acrylate, 0.3 parts by mass of initiator benzoyl peroxide, 10 parts by mass of dipropylene glycol butyl ether, and 0.26 parts by mass of chain transfer agent mercaptoethanol are mixed to obtain a monomer mixture; under nitrogen protection, 1 / 3 of the monomer mixture is heated to 80° C. for copolymerization for 1 hour, and then the remaining 2 / 3 of the monomer mixture is added dropwise, and the addition is completed within 1.5 to 2 hours. The reaction is continued at this temperature for 2 hours, and then the temperature is lowered to 60° C., dimethylethanolamine is added dropwise at 400 to 600 rpm to adjust the pH to 8 to 9, and then distilled water is added dropwise to adjust the solid content to 40% to obtain a weather-resistant acrylic copolymer.

[0018] Furthermore, the preparation method of the N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyl triazine is as follows:

[0019] Mix 17-18 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine, 17-18 parts by mass of 2-chloro-4,6-diallyltriazine and 170-172 parts by mass of m-xylene, stir at 60°C for 4 hours, slowly add 18 parts by mass of 20% sodium hydroxide solution, continue stirring and react for 3.5-4.5 hours, and after the reaction is completed, separate the organic phase, then wash and separate it with 10% sodium chloride solution, then freeze it in a refrigerator for 12 hours, filter it, and dry it in a vacuum oven at 80°C for 12 hours.

[0020] Furthermore, the preparation steps of the modified talc are as follows:

[0021] Aluminum nitrate and calcium nitrate are dissolved in water at a molar ratio of 1:2 to obtain solution A with an aluminum nitrate content of 0.1 mol / L and a calcium nitrate content of 0.2 mol / L; allylglycine and sodium hydroxide are dissolved in water to obtain solution B, wherein the volume of water in solution B is the same as the volume of water in solution A, the amount of allylglycine is equal to the amount of calcium nitrate, and the amount of sodium hydroxide is 2.77 times the sum of the amounts of aluminum nitrate and calcium nitrate; under nitrogen protection, solution B is added dropwise to solution A, and after the addition is completed, the pH is adjusted to 8.5-9.5 with nitric acid, and the solution is stirred for 12 hours, aged at 150°C for 12 hours, filtered and washed after cooling, dried in an oven at 80°C for 12 hours, and ground to obtain modified talc powder.

[0022] The present invention also provides an application method of weather-resistant water-based vehicle body paint, which comprises the following application steps: first, mixing 100 parts by mass of component A and 10 to 13 parts by mass of component B and ball-milling them for 5 to 7 hours to obtain a mixture; spraying the mixture on a polished vehicle body; placing the mixture in a drying room at 93 to 97°C under nitrogen protection for 50 to 70 minutes; then removing the mixture; and continuously spraying 6 to 12 parts by mass of component C; and continuously placing the mixture in a drying room at 113 to 117°C for 10 to 14 hours, and then removing the mixture.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The weather-resistant water-based vehicle body paint of the present invention comprises, by weight, 100 parts by weight of component A, 10 to 13 parts by weight of component B, and 6 to 12 parts by weight of component C; component A comprises, by weight, 15 to 20 parts by weight of water, 35 to 40 parts by weight of weather-resistant acrylic copolymer, 1.4 to 1.6 parts by weight of dispersant, 0.08 to 0.1 parts by weight of defoamer, 9 to 11 parts by weight of rust-proof pigment, 1 to 3 parts by weight of carbon black powder, 7 to 9 parts by weight of 800-mesh sericite powder, 11 to 13 parts by weight of modified talc powder, 0.15 to 0.2 parts by weight of wetting agent, 1.5 to 2 parts by weight of catalyst, 0.3 to 0.35 parts by weight of thickener, 3 to 3 .5 parts by weight of co-solvent ethylene glycol monobutyl ether; component B includes, by weight: 95-98 parts by weight of aqueous epoxy emulsion, 2-2.5 parts by weight of film-forming aid dipropylene glycol butyl ether, 2-5 parts by weight of water, and 0.3 parts by weight of ammonium persulfate; component C includes, by weight, 4-8 parts by weight of perfluorooctyltriethoxysilane and 2-4 parts by weight of water; the weather-resistant acrylic copolymer is obtained by copolymerization of acrylic acid, N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyltriazine, methyl methacrylate, and hydroxyethyl acrylate; the modified talc is allylglycine intercalated calcium aluminum hydrotalcite.

[0025] The present invention adopts the weather-resistant acrylic copolymer in component A and the water-based epoxy emulsion in component B as the base resin, and introduces a large number of polar groups such as hydroxyl and carboxyl groups into the weather-resistant water-based vehicle body paint, so that the weather-resistant water-based vehicle body paint can better adhere to the polished vehicle body, thereby enhancing the adhesion performance of the weather-resistant water-based vehicle body paint.

[0026] The invention obtains a hyperbranched weather-resistant acrylic copolymer by copolymerizing acrylic acid, N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyltriazine, methyl methacrylate, and hydroxyethyl acrylate. An anti-aging agent hindered amine and a triazine ring are introduced into the weather-resistant acrylic copolymer, which can effectively improve the incompatibility between the anti-aging agent hindered amine and the base resin, thereby improving the heat resistance and rigidity of the weather-resistant acrylic copolymer. While the weather-resistant acrylic copolymer has weather resistance, the crosslinking degree of the weather-resistant acrylic copolymer is increased, thereby enhancing the mechanical properties and wear resistance of the weather-resistant acrylic copolymer.

[0027] The invention prepares component A by mixing water, a weather-resistant acrylic copolymer, a dispersant, a defoamer, an anti-rust pigment, carbon black powder, 800-mesh sericite powder, modified talc, a wetting agent, a catalyst, a thickener, and a cosolvent, ethylene glycol monobutyl ether. The modified talc is uniformly dispersed in component A by introducing allyl glycine into the talc. In addition, since a large number of cavities exist in the weather-resistant acrylic copolymer with a hyperbranched structure, the modified talc is embedded in the cavities after being mixed into component A, thereby further uniformly dispersing the modified talc in component A and ensuring the mechanical properties of the weather-resistant water-based vehicle body paint.

[0028] When the present invention is used, after the A component and the B component are mixed, they are placed in an oven at 93-97°C for 50-70 minutes, the modified talcum powder and the weather-resistant acrylic copolymer are polymerized through unsaturated bonds under the action of an initiator, the weather-resistant acrylic copolymer and the water-based epoxy emulsion in the A component and the B component are mixed, the epoxy polymer molecular chains in the water-based epoxy emulsion penetrate into the cavity of the weather-resistant acrylic copolymer, the talcum powder is uniformly dispersed in the weather-resistant water-based car body paint, and after curing, a high cross-linking density car body paint is formed, and at the same time, a dense and uniform hydrotalcite film layer is formed, which enhances the weather-resistant water-based car body paint. The corrosion resistance and hardness of the weather-resistant water-based car body paint are improved; however, the introduction of components A and B introduces more hydrophilic groups such as hydroxyl, amino, and carboxyl groups into the weather-resistant water-based car body paint, which easily leads to poor water resistance of the car paint. When in use, after spraying the mixture of components A and B, component C prepared by spraying perfluorooctyl triethoxysilane is sprayed. Perfluorooctyl triethoxysilane reacts with the hydrophilic groups on the paint surface formed after spraying the mixture of components A and B and self-polymerizes to form a waterproof silicon film on the surface of the weather-resistant water-based car body paint, thereby enhancing the wear resistance, weather resistance, and water resistance of the weather-resistant water-based car body paint. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the weather-resistant water-based vehicle body paint prepared in the following examples.

[0031] A cold-rolled steel plate with a size of 120 mm × 50 mm × 0.5 mm was polished using 80-mesh sandpaper and cleaned with alcohol. Component A and component 1B prepared in each embodiment and comparative example were mixed and ball-milled for 6 h to obtain a mixture. The mixture was sprayed on the polished cold-rolled steel plate, placed in a drying room at 95°C under nitrogen protection for 60 min, then taken out, and component C prepared in each embodiment and comparative example was sprayed. The mixture was continued to be placed in a drying room at 115°C for 12 h and taken out to obtain a painted cold-rolled steel plate.

[0032] Adhesion Test: Adhesion of the paint film was tested according to standard GB / T 9286-1998. The painted cold-rolled steel plate was left at room temperature for one week before testing. A uniform grid was drawn on the paint film using a paint screen. Transparent tape was then applied to the grid, pressing firmly to ensure there were no bubbles. The tape was then quickly removed. Any damage to the grid was observed and compared to a standard to determine the adhesion of the paint film. The test was repeated three times to ensure experimental error.

[0033] Hardness Test: Test the paint film hardness according to standard GB / T 6739-2022. Place the painted cold-rolled steel sheet at room temperature for one week before testing. Place a pencil in the trolley pencil hardness tester and push the trolley pencil hardness tester until the pencil draws a line greater than 7mm on the paint film surface. Test the hardness in descending order, observing any damage to the paint film. Repeat the test five times, and record the maximum hardness without exposing the bottom as the paint film hardness.

[0034] Corrosion Resistance: The paint film's resistance to neutral salt spray was tested according to standard GB / T 1771-2007. The painted cold-rolled steel panels were left at room temperature for one week before testing. Prior to testing, the edges of the panels were sealed with plastic tape. The panels were then placed in a salt spray chamber and observed for corrosion every 12 hours before being returned to their original locations.

[0035] Water resistance: Use 3M tape to seal the edges of the painted cold-rolled steel plate, then soak about 2 / 3 of the steel plate in deionized water and observe whether there is bubbling, peeling or shedding on the surface of the paint film.

[0036] Flexibility: Test the paint film's flexibility according to GB / T 6742-2007. After the painted cold-rolled steel sheet has been left at room temperature for one week, test it. Place the test sheet, paint-side up, against a fixed mandrel and bend it around the mandrel. Observe for any damage to the paint film and record the minimum mandrel diameter that does not cause damage. Repeat the test three times.

[0037] Aging resistance: The painted cold-rolled steel sheets were placed at room temperature for one week and tested according to ASTM G154-2006. Cycle 2 was used and 313 nm lamps were used to irradiate the five groups of paint samples with UV light for 4 hours. The irradiation intensity was 0.71 W / (m 2 The test cycle is 800 hours. The 45° color of the sample is tested every 100 hours. The color difference after 800 hours of UV aging is also tested.

[0038] Some of the raw materials used in the examples and comparative examples of the present invention are as follows:

[0039] The dispersant used was Tego 760W from Evonik Degussa;

[0040] The defoamer used is Tego 810 from Evonik Degussa;

[0041] The anti-rust pigment is SZP-391 from HALOX of the United States;

[0042] The carbon black powder is MA-100 produced by Mitsubishi Chemical;

[0043] The sericite powder is 800 mesh sericite powder from Chuzhou Baota Sericite Mining Co., Ltd.

[0044] The wetting agent used is Tego Win 4000 produced by Evonik Degussa;

[0045] The catalyst is triphenylphosphine;

[0046] The thickener is XS 71 from Gaotai Chemical;

[0047] The water-based epoxy emulsion adopts WE-319 produced by Jili Water-based New Material Technology (Zhuhai) Co., Ltd., and the epoxy equivalent is 1250-1500. Example

[0048] A method for preparing a weather-resistant water-based vehicle body paint comprises the following steps:

[0049] (1) 15 parts by mass of water, 35 parts by mass of weather-resistant acrylic copolymer, 1.4 parts by mass of dispersant, 0.08 parts by mass of defoamer, 9 parts by mass of anti-rust pigment, 1 part by mass of carbon black powder, 7 parts by mass of 800-mesh sericite powder, 11 parts by mass of modified talc powder, 0.15 parts by mass of wetting agent, 1.5 parts by mass of catalyst, 0.3 parts by mass of thickener, and 3 parts by mass of cosolvent ethylene glycol monobutyl ether were poured into a ball mill and dispersed for 6 hours, discharged, sealed and set aside to obtain component A;

[0050] (2) 95 parts by mass of aqueous epoxy emulsion, 2 parts by mass of film-forming aid dipropylene glycol butyl ether, 2 parts by mass of water, and 0.3 parts by mass of ammonium persulfate were mixed and stirred at 100 rpm for 2 hours, discharged, sealed and set aside to obtain component B;

[0051] (3) Mix 4 parts by mass of perfluorooctyltriethoxysilane and 2 parts by mass of water, discharge the mixture, seal it and set it aside to obtain component C;

[0052] (4) 100 parts by mass of component A, 10 parts by mass of component B, and 6 parts by mass of component C are packaged separately and combined into a group to obtain a weather-resistant water-based vehicle body paint.

[0053] Furthermore, the preparation method of the weather-resistant acrylic copolymer is as follows: 0.5 parts by mass of acrylic acid, 2 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyltriazine, 14 parts by mass of methyl methacrylate, 18 parts by mass of hydroxyethyl acrylate, 0.3 parts by mass of initiator benzoyl peroxide, 10 parts by mass of dipropylene glycol butyl ether, and 0.26 parts by mass of chain transfer agent mercaptoethanol are mixed to obtain a monomer mixture; under nitrogen protection, 1 / 3 of the monomer mixture is heated to 80° C. for copolymerization for 1 hour, and then the remaining 2 / 3 of the monomer mixture is added dropwise, and the addition is completed within 1.5 hours. The reaction is continued by keeping the temperature for 2 hours, and then the temperature is lowered to 60° C., dimethylethanolamine is added dropwise at 400 rpm to adjust the pH to 8, and then distilled water is added dropwise to adjust the solid content to 40% to obtain a weather-resistant acrylic copolymer.

[0054] Furthermore, the preparation method of the N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyl triazine is as follows:

[0055] 17 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine, 17 parts by mass of 2-chloro-4,6-diallyltriazine and 170 parts by mass of m-xylene were mixed, stirred at 60°C for 4 hours, 18 parts by mass of 20% sodium hydroxide solution were slowly added dropwise, and the stirring reaction was continued for 3.5 hours. After the reaction was completed, the organic phase was separated and then washed and separated with 10% sodium chloride solution, then frozen in a refrigerator for 12 hours, filtered, and dried in a vacuum oven at 80°C for 12 hours.

[0056] Furthermore, the preparation steps of the modified talc are as follows:

[0057] Aluminum nitrate and calcium nitrate are dissolved in water at a molar ratio of 1:2 to obtain solution A with an aluminum nitrate content of 0.1 mol / L and a calcium nitrate content of 0.2 mol / L; allylglycine and sodium hydroxide are dissolved in water to obtain solution B, wherein the volume of water in solution B is the same as the volume of water in solution A, the amount of allylglycine is equal to the amount of calcium nitrate, and the amount of sodium hydroxide is 2.77 times the sum of the amounts of aluminum nitrate and calcium nitrate; under nitrogen protection, solution B is added dropwise to solution A, and after the addition is completed, the pH is adjusted to 8.5 with nitric acid, and the mixture is stirred for 12 hours and then aged at 150°C for 12 hours. After cooling, the mixture is filtered, washed, and dried in an oven at 80°C for 12 hours. After grinding, modified talc powder with a D50 of 2 μm is obtained. Example

[0058] A method for preparing a weather-resistant water-based vehicle body paint comprises the following steps:

[0059] (1) 18 parts by mass of water, 38 parts by mass of weather-resistant acrylic copolymer, 1.5 parts by mass of dispersant, 0.09 parts by mass of defoamer, 10 parts by mass of rust-proof pigment, 2 parts by mass of carbon black powder, 8 parts by mass of 800-mesh sericite powder, 12 parts by mass of modified talc, 0.18 parts by mass of wetting agent, 1.8 parts by mass of catalyst, 0.33 parts by mass of thickener, and 3.3 parts by mass of cosolvent ethylene glycol monobutyl ether were poured into a ball mill and dispersed for 6 hours, discharged, and sealed for standby use to obtain component A;

[0060] (2) 97 parts by mass of aqueous epoxy emulsion, 2.3 parts by mass of film-forming aid dipropylene glycol butyl ether, 3 parts by mass of water, and 0.3 parts by mass of ammonium persulfate were mixed and stirred at 150 rpm for 3 hours, discharged, and sealed for use to obtain component B;

[0061] (3) Mix 6 parts by mass of perfluorooctyltriethoxysilane and 3 parts by mass of water, discharge the mixture, seal it and set it aside to obtain component C;

[0062] (4) 100 parts by mass of component A, 12 parts by mass of component B, and 9 parts by mass of component C were packaged separately and combined into a group to obtain a weather-resistant water-based vehicle body paint.

[0063] Furthermore, the preparation method of the weather-resistant acrylic copolymer is as follows: 0.5 parts by mass of acrylic acid, 4 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyltriazine, 14 parts by mass of methyl methacrylate, 18 parts by mass of hydroxyethyl acrylate, 0.3 parts by mass of initiator benzoyl peroxide, 10 parts by mass of dipropylene glycol butyl ether, and 0.26 parts by mass of chain transfer agent mercaptoethanol are mixed to obtain a monomer mixture; under nitrogen protection, 1 / 3 of the monomer mixture is heated to 80° C. for copolymerization for 1 hour, and then the remaining 2 / 3 of the monomer mixture is added dropwise, and the addition is completed within 1.8 hours. The reaction is continued by keeping the temperature for 2 hours, and then the temperature is lowered to 60° C., dimethylethanolamine is added dropwise at 500 rpm to adjust the pH to 8.5, and then distilled water is added dropwise to adjust the solid content to 40% to obtain a weather-resistant acrylic copolymer.

[0064] Furthermore, the preparation method of the N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyl triazine is as follows:

[0065] 17.5 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine, 17.5 parts by mass of 2-chloro-4,6-diallyltriazine and 171 parts by mass of m-xylene were mixed, stirred at 60°C for 4 hours, 18 parts by mass of 20% sodium hydroxide solution were slowly added dropwise, and the stirring reaction was continued for 4 hours. After the reaction was completed, the organic phase was separated and then washed and separated with 10% sodium chloride solution, then frozen in a refrigerator for 12 hours, filtered, and dried in a vacuum oven at 80°C for 12 hours.

[0066] Furthermore, the preparation steps of the modified talc are as follows:

[0067] Aluminum nitrate and calcium nitrate are dissolved in water at a molar ratio of 1:2 to obtain solution A with an aluminum nitrate content of 0.1 mol / L and a calcium nitrate content of 0.2 mol / L; allylglycine and sodium hydroxide are dissolved in water to obtain solution B, wherein the volume of water in solution B is the same as the volume of water in solution A, the amount of allylglycine is equal to the amount of calcium nitrate, and the amount of sodium hydroxide is 2.77 times the sum of the amounts of aluminum nitrate and calcium nitrate; under nitrogen protection, solution B is added dropwise to solution A, and after the addition is completed, the pH is adjusted to 9 with nitric acid, and the mixture is stirred for 12 hours and then aged at 150°C for 12 hours. After cooling, the mixture is filtered, washed, dried in an oven at 80°C for 12 hours, and ground to obtain modified talc powder with a D50 of 4 μm. Example

[0068] A method for preparing a weather-resistant water-based vehicle body paint comprises the following steps:

[0069] (1) 20 parts by mass of water, 40 parts by mass of weather-resistant acrylic copolymer, 1.6 parts by mass of dispersant, 0.1 parts by mass of defoamer, 11 parts by mass of anti-rust pigment, 3 parts by mass of carbon black powder, 9 parts by mass of 800-mesh sericite powder, 13 parts by mass of modified talc powder, 0.2 parts by mass of wetting agent, 2 parts by mass of catalyst, 0.35 parts by mass of thickener, and 3.5 parts by mass of cosolvent ethylene glycol monobutyl ether were poured into a ball mill and dispersed for 6 hours, discharged, and sealed for standby use to obtain component A;

[0070] (2) 98 parts by mass of aqueous epoxy emulsion, 2.5 parts by mass of film-forming aid dipropylene glycol butyl ether, 5 parts by mass of water, and 0.3 parts by mass of ammonium persulfate were mixed and stirred at 200 rpm for 4 hours, discharged, and sealed for use to obtain component B;

[0071] (3) 8 parts by mass of perfluorooctyltriethoxysilane and 4 parts by mass of water were mixed, discharged, and sealed for standby use to obtain component C;

[0072] (4) 100 parts by mass of component A, 13 parts by mass of component B, and 12 parts by mass of component C were packaged separately and combined into a group to obtain a weather-resistant water-based vehicle body paint.

[0073] Furthermore, the preparation method of the weather-resistant acrylic copolymer is as follows: 0.5 parts by mass of acrylic acid, 6 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyltriazine, 14 parts by mass of methyl methacrylate, 18 parts by mass of hydroxyethyl acrylate, 0.3 parts by mass of initiator benzoyl peroxide, 10 parts by mass of dipropylene glycol butyl ether, and 0.26 parts by mass of chain transfer agent mercaptoethanol are mixed to obtain a monomer mixture; under nitrogen protection, 1 / 3 of the monomer mixture is heated to 80° C. for copolymerization for 1 hour, and then the remaining 2 / 3 of the monomer mixture is added dropwise, and the addition is completed within 2 hours. The reaction is continued by keeping the temperature for 2 hours, and then the temperature is lowered to 60° C., dimethylethanolamine is added dropwise at 600 rpm to adjust the pH to 9, and then distilled water is added dropwise to adjust the solid content to 40% to obtain a weather-resistant acrylic copolymer.

[0074] Furthermore, the preparation method of the N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyl triazine is as follows:

[0075] 18 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine, 18 parts by mass of 2-chloro-4,6-diallyltriazine and 172 parts by mass of m-xylene were mixed, stirred at 60°C for 4 hours, 18 parts by mass of 20% sodium hydroxide solution were slowly added dropwise, and the stirring reaction was continued for 4.5 hours. After the reaction was completed, the organic phase was separated and then washed and separated with 10% sodium chloride solution, then frozen in a refrigerator for 12 hours, filtered, and dried in a vacuum oven at 80°C for 12 hours.

[0076] Furthermore, the preparation steps of the modified talc are as follows:

[0077] Aluminum nitrate and calcium nitrate are dissolved in water at a molar ratio of 1:2 to obtain solution A with an aluminum nitrate content of 0.1 mol / L and a calcium nitrate content of 0.2 mol / L; allylglycine and sodium hydroxide are dissolved in water to obtain solution B, wherein the volume of water in solution B is the same as the volume of water in solution A, the amount of allylglycine is equal to the amount of calcium nitrate, and the amount of sodium hydroxide is 2.77 times the sum of the amounts of aluminum nitrate and calcium nitrate; under nitrogen protection, solution B is added dropwise to solution A, and after the addition is completed, the pH is adjusted to 9.5 with nitric acid, and the mixture is stirred for 12 hours, aged at 150°C for 12 hours, filtered and washed after cooling, and dried in an oven at 80°C for 12 hours. After grinding, modified talc powder with a D50 of 6 μm is obtained.

[0078] Comparative Example 1

[0079] The only difference between Comparative Example 1 and Example 2 is that the weather-resistant acrylic copolymer is obtained by copolymerizing only acrylic acid, methyl methacrylate, and hydroxyethyl acrylate, and 0.5 parts by mass of the antioxidant N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine is added to component A; the remaining components, proportions, and processes are the same as those in Example 2.

[0080] Comparative Example 2

[0081] The only difference between Comparative Example 2 and Example 2 is that component A is prepared by mixing water, weather-resistant acrylic copolymer, dispersant, defoaming agent, rust-proof pigment, carbon black powder, 800 mesh sericite powder, talc, wetting agent, catalyst, thickener, and co-solvent ethylene glycol monobutyl ether; the remaining components, proportions, and processes are the same as those in Example 2.

[0082] Comparative Example 3

[0083] The only difference between Comparative Example 3 and Example 2 is that component A is prepared by mixing water, weather-resistant acrylic copolymer, dispersant, defoamer, rust-proof pigment, carbon black powder, 800 mesh sericite powder, 3000 mesh precipitated barium sulfate, wetting agent, catalyst, thickener, and co-solvent ethylene glycol monobutyl ether; the remaining components, proportions, and processes are the same as those in Example 2.

[0084] Comparative Example 4

[0085] The only difference between Comparative Example 4 and Example 2 is that the weather-resistant water-based vehicle body paint only includes component A and component B; the remaining components, proportions and processes are the same as those in Example 2.

[0086] Effect Examples

[0087] Table 1 below shows the performance analysis results of the weather-resistant water-based vehicle body paints of Examples 1 to 3 of the present invention and Comparative Examples 1 to 4.

[0088] Table 1

[0089] Adhesion / Grade Pencil hardness Flexibility / mm Neutral salt spray resistance Water resistance Weather resistance - color difference Example 1 0 3H 2 340h no rust 360h paint film does not bubble or rust 5.93 Example 2 0 3H 2 340h no rust 360h paint film does not bubble or rust 5.86 Example 3 0 3H 2 340h no rust 360h paint film does not bubble or rust 5.92 Comparative Example 1 0 2H 4 280h rust 360h paint film does not bubble or rust 8.64 Comparative Example 2 0 2H 6 260h rust 300h foaming 5.90 Comparative Example 3 0 H 4 290h rust 320h paint film blistering 5.93 Comparative Example 4 0 H 2 240h ​​rust 160h foaming 5.88

[0090] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 4 in Table 1, it can be found that the weather-resistant water-based car body paint films prepared in the examples have good mechanical properties, adhesion properties, corrosion resistance, water resistance, and high coating hardness; from the comparison of the experimental data of Example 2 and Comparative Example 1, it can be found that the weather-resistant water-based car body paint films prepared in the examples have good mechanical properties, adhesion properties, corrosion resistance, water resistance, and high coating hardness; ... The body paint, the weather-resistant water-based body paint film has high mechanical properties, corrosion resistance and coating hardness; from the comparison of the experimental data of Example 2 and Comparative Examples 2~3, it can be found that the weather-resistant water-based body paint is prepared by using allylglycine intercalated calcium aluminum hydrotalcite, and the prepared weather-resistant water-based body paint film has good mechanical properties, corrosion resistance and water resistance, and the coating hardness is high; from the comparison of the experimental data of Example 2 and Comparative Example 4, it can be found that the weather-resistant water-based body paint is also provided with a C component, and the prepared weather-resistant water-based body paint film has good corrosion resistance and water resistance, and the coating hardness is high.

[0091] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A weather-resistant water-based vehicle body paint, characterized in that: The raw material components include 100 parts by weight of component A, 10-13 parts by weight of component B, and 6-12 parts by weight of component C; component A includes, by weight: 15-20 parts by weight of water, 35-40 parts by weight of weather-resistant acrylic copolymer, 1.4-1.6 parts by weight of dispersant, 0.08-0.1 parts by weight of defoamer, 9-11 parts by weight of anti-rust pigment, 1-3 parts by weight of carbon black powder, 7-9 parts by weight of 800 mesh sericite powder, 11-13 parts by weight of modified talc, 0.15-0.2 parts by mass of a wetting agent, 1.5-2 parts by mass of a catalyst, 0.3-0.35 parts by mass of a thickener, and 3-3.5 parts by mass of a co-solvent, ethylene glycol monobutyl ether; component B comprises, by weight: 95-98 parts by mass of an aqueous epoxy emulsion, 2-2.5 parts by mass of a film-forming aid, dipropylene glycol butyl ether, 2-5 parts by mass of water, and 0.3 parts by mass of ammonium persulfate; component C comprises, by weight: 4-8 parts by mass of a fluorosilicone and 2-4 parts by mass of water; The weather-resistant acrylic copolymer is obtained by copolymerizing acrylic acid, N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyl triazine, methyl methacrylate, and hydroxyethyl acrylate. The modified talc powder is allylglycine intercalated calcium aluminum hydrotalcite.

2. The weather-resistant water-based vehicle body paint according to claim 1, characterized in that: The modified talc has a D50 of 2-6 μm.

3. A method for preparing a weather-resistant water-based vehicle body paint, characterized in that: The method comprises the following preparation steps: (1) Mixing the raw materials according to the raw material components and proportions of claim 1; (2) 15-20 parts by mass of water, 35-40 parts by mass of weather-resistant acrylic copolymer, 1.4-1.6 parts by mass of dispersant, 0.08-0.1 parts by mass of defoamer, 9-11 parts by mass of anti-rust pigment, 1-3 parts by mass of carbon black powder, 7-9 parts by mass of 800-mesh sericite powder, 11-13 parts by mass of modified talc powder, 0.15-0.2 parts by mass of wetting agent, 1.5-2 parts by mass of catalyst, 0.3-0.35 parts by mass of thickener, and 3-3.5 parts by mass of co-solvent ethylene glycol monobutyl ether were poured into a ball mill and dispersed for 6 hours, discharged, sealed and set aside to obtain component A; (3) Mix 95-98 parts by mass of aqueous epoxy emulsion, 2-2.5 parts by mass of film-forming aid dipropylene glycol butyl ether, 2-5 parts by mass of water, and 0.3 parts by mass of ammonium persulfate, and stir at 100-200 rpm for 2-4 hours, discharge, seal, and set aside to obtain component B; (4) Mixing 4 to 8 parts by mass of fluorosilicone and 2 to 4 parts by mass of water, discharging the mixture, sealing the mixture for standby use, and obtaining component C; (5) 100 parts by mass of component A, 10 to 13 parts by mass of component B, and 6 to 12 parts by mass of component C are packaged separately and combined into a group to obtain a weather-resistant water-based vehicle body paint.

4. The method for preparing the weather-resistant water-based vehicle body paint according to claim 3, characterized in that: The preparation method of the weather-resistant acrylic copolymer is as follows: 0.5 parts by mass of acrylic acid, 2-6 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyltriazine, 14 parts by mass of methyl methacrylate, 18 parts by mass of hydroxyethyl acrylate, 0.3 parts by mass of initiator benzoyl peroxide, 10 parts by mass of dipropylene glycol butyl ether, and 0.26 parts by mass of chain transfer agent mercaptoethanol are mixed to obtain a monomer mixture; under nitrogen protection, 1 / 3 of the monomer mixture is heated to 80° C. for copolymerization for 1 hour, and then the remaining 2 / 3 of the monomer mixture is dropwise added within 1.5-2 hours, the reaction is continued at this temperature for 2 hours, and then the temperature is lowered to 60° C., dimethylethanolamine is dropwise added at 400-600 rpm to adjust the pH to 8-9, and then distilled water is dropwise added to adjust the solid content to 40% to obtain the weather-resistant acrylic copolymer.

5. The method for preparing the weather-resistant water-based vehicle body paint according to claim 4, characterized in that: The preparation method of the N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine-modified 2-chloro-4,6-diallyl triazine is as follows: Mix 17-18 parts by mass of N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine, 17-18 parts by mass of 2-chloro-4,6-diallyltriazine and 170-172 parts by mass of m-xylene, stir at 60°C for 4 hours, slowly add 18 parts by mass of 20% sodium hydroxide solution, continue stirring and react for 3.5-4.5 hours, and after the reaction is completed, separate the organic phase, then wash and separate it with 10% sodium chloride solution, then freeze it in a refrigerator for 12 hours, filter it, and dry it in a vacuum oven at 80°C for 12 hours.

6. The method for preparing the weather-resistant water-based vehicle body paint according to claim 3, characterized in that: The preparation steps of the modified talcum powder are as follows: Aluminum nitrate and calcium nitrate are dissolved in water at a molar ratio of 1:2 to obtain solution A with an aluminum nitrate content of 0.1 mol / L and a calcium nitrate content of 0.2 mol / L; allylglycine and sodium hydroxide are dissolved in water to obtain solution B, wherein the volume of water in solution B is the same as the volume of water in solution A, the amount of allylglycine is equal to the amount of calcium nitrate, and the amount of sodium hydroxide is 2.77 times the sum of the amounts of aluminum nitrate and calcium nitrate; under nitrogen protection, solution B is added dropwise to solution A, and after the addition is completed, the pH is adjusted to 8.5-9.5 with nitric acid, and the solution is stirred for 12 hours, aged at 150°C for 12 hours, filtered and washed after cooling, dried in an oven at 80°C for 12 hours, and ground to obtain modified talc powder.

7. A method for applying the weather-resistant water-based vehicle body paint according to any one of claims 1 to 2, characterized in that: The application steps are as follows: first, 100 parts by mass of component A and 10-13 parts by mass of component B are mixed and ball-milled for 5-7 hours to obtain a mixture, the mixture is sprayed on a polished vehicle body, and the mixture is placed in a drying room at 93-97°C under nitrogen protection for 50-70 minutes, then taken out, and 6-12 parts by mass of component C are continuously sprayed, and the mixture is placed in a drying room at 113-117°C and dried for 10-14 hours, and then taken out.