Antibacterial coating for vehicle chassis and preparation method thereof

Abstract

The invention relates to the technical field of protective coatings, in particular to an antibacterial coating for a vehicle chassis and a preparation method of the antibacterial coating. The antibacterial coating for the vehicle chassis is prepared from the following components in parts by weight: 30 to 50 parts of acrylic emulsion, 10 to 20 parts of a compound additive, 6 to 10 parts of nano calcium carbonate, 2 to 5 parts of silicon carbide, 2 to 4 parts of carbon black, 1 to 2 parts of bentonite, 2 to 3 parts of nano zinc oxide, 2 to 3 parts of dipropylene glycol butyl ether, 3 to 5 parts of tetraphenyl bisphenol-A-diphosphate, 0.6 to 1.2 parts of zinc strontium phosphate and 0.8 to 1.5 parts of iron oxide yellow. The coating is prepared from the following components in parts by weight: 0.2 to 0.5 part of 2-methyl-4-isothiazolin-3-ketone, 0.5 to 1 part of a flatting agent, 0.6 to 1.2 parts of a wetting agent, 0.5 to 1 part of a defoaming agent, 0.3 to 0.8 part of a dispersing agent and 10 to 20 parts of water. The antibacterial coating prepared by the invention not only has excellent antibacterial performance, but also has excellent wear resistance, so that the wear resistance of the vehicle chassis is effectively improved, and the probability that the vehicle chassis is scratched is reduced; and meanwhile, microbial erosion in a humid environment can be resisted, the durability and reliability of vehicle chassis protection are remarkably improved, and the service life of the vehicle chassis is prolonged to a certain extent.

Description

Technical Field

[0001] This invention relates to the field of protective coating technology, specifically to an antibacterial coating for vehicle chassis and its preparation method. Background Technology

[0002] As a critical component directly in contact with the road surface, the vehicle chassis is constantly exposed to a complex and harsh environment, enduring multiple challenges such as impacts from gravel, mud and water splashes, chemical corrosion, and the growth of microorganisms (such as bacteria and mold) due to moisture and dirt accumulation. Microbial growth can not only accelerate the biocorrosion of chassis metal components, affecting vehicle safety and lifespan, but may also produce unpleasant odors. Therefore, effective multi-functional protection for the vehicle chassis is crucial.

[0003] Traditional chassis coatings (such as asphalt-based and epoxy-based coatings) can provide some rust prevention and sound insulation, but their overall performance often falls short of increasingly demanding requirements. Specifically, they are insufficient in long-term wear resistance and impact resistance, and are easily damaged by sand and gravel, leading to protective failure. At the same time, traditional coatings generally lack active and long-lasting antibacterial functions, and cannot inhibit the growth of microorganisms and the formation of biofilms in the humid environment of the chassis.

[0004] Currently, there are some functional coatings on the market that contain antibacterial agents (such as inorganic silver ions and organic quaternary ammonium salts). However, these technologies often face the following bottlenecks: First, the antibacterial components have poor compatibility with the coating matrix, are prone to migration and loss, resulting in short-lasting antibacterial efficacy and potentially affecting the physical properties of the coating; second, their wear resistance is relatively poor, and it is difficult to meet the requirements for multiple properties of coatings, such as antibacterial, wear resistance, and corrosion resistance.

[0005] Therefore, the present invention provides an antibacterial coating for vehicle chassis and a method for preparing the same, in order to solve the aforementioned technical problems. Summary of the Invention

[0006] This invention provides an antibacterial coating for vehicle chassis and its preparation method. The prepared antibacterial coating not only has excellent antibacterial properties but also excellent wear resistance, effectively improving the wear resistance of the vehicle chassis and reducing the probability of scratches. Simultaneously, it can resist microbial erosion in humid environments, significantly improving the durability and reliability of vehicle chassis protection and extending its service life to a certain extent.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An antibacterial coating for vehicle chassis is made from the following components in parts by weight: 30-50 parts acrylic emulsion, 10-20 parts composite additives, 6-10 parts nano calcium carbonate, 2-5 parts silicon carbide, 2-4 parts carbon black, 1-2 parts bentonite, 2-3 parts nano zinc oxide, 2-3 parts dipropylene glycol butyl ether, 3-5 parts tetraphenylbisphenol-A-diphosphate, 0.6-1.2 parts zinc strontium phosphate, 0.8-1.5 parts iron oxide yellow, 0.2-0.5 parts 2-methyl-4-isothiazolin-3-one, 0.5-1 part leveling agent, 0.6-1.2 parts wetting agent, 0.5-1 part defoamer, 0.3-0.8 parts dispersant, and 10-20 parts water.

[0008] Furthermore, the preparation method of the composite additive is as follows: Step 1: Dissolve 2-phosphonobutane-1,2,4-tricarboxylic acid in deionized water to prepare an acid solution with a concentration of 3-5 wt%. Add 30-40% of deacetylated chitin to 2-phosphonobutane-1,2,4-tricarboxylic acid and stir until fully dissolved. Heat the resulting mixture to 80-85°C and add formaldehyde dropwise at a volume of 1-2% of the acid solution. Reflux for 1-2 hours and then maintain the temperature for 5-8 hours. After the reaction is complete, rotary evaporate the reaction product to remove unreacted formaldehyde and water. The resulting concentrate is then vacuum dried and ground to obtain the modifier. Step 2: Add EDC at a mass of 0.3-0.4 times that of the modifier to a 5-8 wt% aqueous solution of the modifier, stir for 10-20 min, then add NHS at a molar mass equal to that of EDC and react for 1-2 h; then add aminated spherical substrate at a mass of 0.5-1 times that of the modifier and polyhexamethylene biguanide at a mass of 0.2-0.5 times, and disperse evenly. After reacting at room temperature for 5-8 h, the reaction solution is centrifuged, washed with water, and vacuum dried sequentially to obtain the final product.

[0009] Furthermore, the preparation method of the aminated spherical substrate is as follows: the nano-spherical substrate is immersed in an 85-90wt% ethanol aqueous solution at a mass ratio of 1:10-20, γ-aminopropyltrimethoxysilane is added at a mass of 20-30% of the ethanol aqueous solution, and the reaction is carried out at 60-70℃ for 3-5 hours. The reaction solution is then subjected to solid-liquid separation, washing and drying treatment to obtain the substrate.

[0010] Furthermore, the method for preparing the spherical substrate is as follows: 0.5-0.8 g / mL of zirconium oxychloride aqueous solution and 0.2-0.3 g / mL of cerium nitrate aqueous solution are mixed at a volume ratio of 1-2:1. Modified porous polymethyl methacrylate microspheres with a mass of 2-3 times that of zirconium oxychloride and anhydrous ethanol with a volume equal to that of the zirconium oxychloride aqueous solution are added sequentially. The mixture is ultrasonically dispersed until there are no obvious large solid particles, and then reacted at 90-120℃ for 10-20 h. The reaction solution is filtered, and the filter cake is calcined at 500-600℃ for 4-6 h, and then naturally cooled to room temperature to obtain the final product.

[0011] Furthermore, the modified porous polymethyl methacrylate microspheres are prepared by ultrasonically dispersing 2-5g of porous polymethyl methacrylate microspheres in 100-200mL of deionized water, adding 5-8g of ethylenediamine, reacting at 75-85℃ for 10-15h, filtering, washing with water until neutral, washing with ethanol 3-4 times, and then vacuum drying at 40-60℃ to obtain the product.

[0012] Furthermore, the leveling agent is any one of BYK-378, BASF EFKAFL 3772, or BYK-331.

[0013] Furthermore, the wetting agent is at least one of TEGO-270 wetting agent and TEGO-265 wetting agent.

[0014] Furthermore, the defoamer is any one of TEGO-8030, Dow Corning AFE-3168, and BYK-A530.

[0015] Furthermore, the dispersant is any one of BYK-190, Dow 731A, and BYK-192.

[0016] A method for preparing an antibacterial coating for vehicle chassis includes the following steps: weighing each component according to the formula amount, adding each component to a mixing device for mixing and stirring, and after stirring evenly, grinding the resulting mixed slurry with a sand mill until the fineness is less than 10μm; then filtering and filling, the result is the antibacterial coating for vehicle chassis.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses zirconium oxychloride, cerium nitrate, and modified porous polymethyl methacrylate microspheres as raw materials to prepare a spherical carrier with a porous structure composed of nano-zirconium dioxide and nano-cerium oxide through chemical reaction. Then, the spherical carrier is aminated with γ-aminopropyltrimethoxysilane to introduce active amino groups on its surface, facilitating subsequent reactions. Simultaneously, this invention uses 2-phosphonobutane-1,2,4-tricarboxylic acid, chitin, and formaldehyde as raw materials. Under the action of formaldehyde, 2-phosphonobutane-1,2,4-tricarboxylic acid reacts chemically with chitin to form a bond, ultimately preparing an antibacterial organic macromolecule—a modifier—with active reactive groups. The modifier is then dissolved in water and activated using EDC and NHS to enhance the reactivity of its active groups, laying a theoretical foundation for subsequent chemical reactions.

[0018] 2. The prepared aminated spherical substrate is added to an activated modifier solution, and polyhexamethylene biguanide is added and uniformly dispersed. This allows the polyhexamethylene biguanide to be effectively dispersed and loaded on the surface of the aminated spherical substrate and inside its porous structure. Simultaneously, the activated reactive groups on the modifier molecular chain react chemically with the amino groups to form bonds, ultimately forming a crisscrossing three-dimensional antibacterial "mesh layer" on the surface of the aminated spherical substrate and inside its porous structure. The presence of this mesh layer not only significantly enhances the antibacterial performance of the spherical carrier but also effectively "binds" the polyhexamethylene biguanide adsorbed and retained inside and on the surface of the aminated spherical substrate, reducing its migration probability. Ultimately, through the synergistic effect of the spherical substrate, polyhexamethylene biguanide, and modifier, the prepared composite additive exhibits excellent antibacterial properties.

[0019] Furthermore, since the spherical substrate prepared by this invention uses nano-zirconia and nano-cerium oxide, which have excellent wear resistance, as raw materials, and has a spherical morphology, it exhibits a "ball bearing effect." When this antibacterial coating is applied to the vehicle chassis, during the relative movement between the antibacterial coating and external wear objects (such as sand particles), these uniformly dispersed spherical substrates act like "miniature bearings," partially converting sliding friction into rolling friction, thereby effectively reducing the frictional resistance of the coating surface and alleviating wear on the vehicle chassis.

[0020] In summary, the antibacterial coating prepared by this invention not only possesses excellent antibacterial properties but also superior wear resistance, effectively improving the wear resistance of vehicle chassis and reducing the likelihood of scratches. Simultaneously, it can resist microbial erosion in humid environments, significantly enhancing the durability and reliability of vehicle chassis protection and extending its service life to a certain extent. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] The relevant information of the raw materials used in the following examples is as follows: The acrylic emulsion is E-1206 type environmentally friendly water-based acrylic emulsion with a molecular weight of 10,000-20,000 and a viscosity of 2,000-3,000 cps.

[0023] The degree of deacetylation of deacetylated chitosan is 80-95%.

[0024] The polymethyl methacrylate microspheres have a particle size of 0.6-2 μm, a pore size of 20-40 nm, and a crosslinking degree of 40-70%.

[0025] EDC stands for 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; NHS stands for N-hydroxysuccinimide. Example 1:

[0026] An antibacterial coating for vehicle chassis is made from the following components in parts by weight: 30 parts acrylic emulsion, 10 parts composite additives, 6 parts nano calcium carbonate, 2 parts silicon carbide, 2 parts carbon black, 1 part bentonite, 2 parts nano zinc oxide, 2 parts dipropylene glycol butyl ether, 3 parts tetraphenylbisphenol-A-diphosphate, 0.6 parts zinc strontium phosphate, 0.8 parts iron oxide yellow, 0.2 parts 2-methyl-4-isothiazolin-3-one, 0.5 parts BYK-378 leveling agent, 0.6 parts TEGO-270 wetting agent, 0.5 parts TEGO-8030 defoamer, 0.3 parts BYK-190 dispersant, and 10 parts water.

[0027] The preparation method of the composite additive is as follows: Step 1: Dissolve 2-phosphonobutane-1,2,4-tricarboxylic acid in deionized water to prepare an acid solution with a concentration of 3 wt%. Add 30% deacetylated chitin of 2-phosphonobutane-1,2,4-tricarboxylic acid and stir until fully dissolved. Heat the resulting mixture to 80°C and add formaldehyde at a volume of 1% of the acid solution. Reflux for 2 hours and then maintain the temperature for 8 hours. After the reaction is complete, rotary evaporate the reaction product to remove unreacted formaldehyde and water. The resulting concentrate is then vacuum dried and ground to obtain the modifier. Step 2: Add EDC at a mass of 0.3 times that of the modifier to a 5 wt% aqueous solution of the modifier, stir for 10 min, then add NHS at a molar amount equal to that of EDC and react for 1 h; then add aminated spherical substrate at a mass of 0.5 times that of the modifier and polyhexamethylene biguanide at a mass of 0.2 times, and disperse evenly. After reacting at room temperature for 5 h, the reaction solution is centrifuged, washed with water, and vacuum dried sequentially to obtain the final product.

[0028] The preparation method of the aminated spherical substrate is as follows: the nanosphere substrate is immersed in an 85wt% ethanol aqueous solution at a mass ratio of 1:10, γ-aminopropyltrimethoxysilane at a mass of 20% of the ethanol aqueous solution is added, and the reaction is carried out at 60℃ for 5h. The reaction solution is then subjected to solid-liquid separation, washing and drying treatment to obtain the substrate.

[0029] The spherical substrate is prepared as follows: 0.5 g / mL zirconium oxychloride aqueous solution and 0.2 g / mL cerium nitrate aqueous solution are mixed at a volume ratio of 1:1. Modified porous polymethyl methacrylate microspheres with a mass twice that of zirconium oxychloride and anhydrous ethanol with a volume equal to that of zirconium oxychloride aqueous solution are added sequentially. The mixture is ultrasonically dispersed until there are no obvious large solid particles, and then reacted at 90℃ for 20 h. The reaction solution is filtered, and the filter cake is calcined at 500℃ for 6 h and then naturally cooled to room temperature to obtain the final product.

[0030] The modified porous polymethyl methacrylate microspheres are prepared as follows: 2g of porous polymethyl methacrylate microspheres are ultrasonically dispersed in 100mL of deionized water, and then 5g of ethylenediamine is added. After reacting at 75℃ for 15h, the mixture is filtered, washed with water until neutral, washed three times with ethanol, and then vacuum dried at 40℃ to obtain the microspheres.

[0031] A method for preparing an antibacterial coating for vehicle chassis includes the following steps: weighing each component according to the formula amount, adding each component to a mixing device for mixing and stirring, and after stirring evenly, grinding the resulting mixed slurry to a fineness of 8μm using a sand mill; then filtering and filling, the resulting antibacterial coating for vehicle chassis is obtained. Example 2:

[0032] The preparation method of the antibacterial coating for vehicle chassis provided in this embodiment is basically the same as that in Example 1, except that the specific proportions of the raw materials and the preparation methods of the composite additives are different. The specific proportions of the raw materials and the preparation methods of the composite additives in this embodiment are as follows: An antibacterial coating for vehicle chassis is made from the following components in parts by weight: 40 parts acrylic emulsion, 15 parts composite additives, 8 parts nano calcium carbonate, 3 parts silicon carbide, 3 parts carbon black, 2 parts bentonite, 3 parts nano zinc oxide, 3 parts dipropylene glycol butyl ether, 4 parts tetraphenylbisphenol-A-diphosphate, 1 part zinc strontium phosphate, 1.2 parts iron oxide yellow, 0.4 parts 2-methyl-4-isothiazolin-3-one, 0.8 parts BASF EFKAFL 3772 leveling agent, 1 part TEGO-265 wetting agent, 0.8 parts Dow Corning AFE-3168 defoamer, 0.6 parts Dow 731A dispersant, and 15 parts water.

[0033] The preparation method of the composite additive is as follows: Step 1: Dissolve 2-phosphonobutane-1,2,4-tricarboxylic acid in deionized water to prepare an acid solution with a concentration of 4 wt%. Add 35% deacetylated chitosan of 2-phosphonobutane-1,2,4-tricarboxylic acid and stir until fully dissolved. Heat the resulting mixture to 85°C and add formaldehyde at a volume of 2% of the acid solution. Reflux for 2 hours and then keep the mixture at this temperature for 6 hours. After the reaction is complete, rotary evaporate the reaction product to remove unreacted formaldehyde and water. The resulting concentrate is then vacuum dried and ground to obtain the modifier. Step 2: Add EDC at a mass of 0.4 times that of the modifier to a 6 wt% aqueous solution of the modifier, stir for 15 min, then add NHS in an equal molar amount to EDC and react for 2 h; then add aminated spherical substrate at a mass of 0.8 times that of the modifier and polyhexamethylene biguanide at a mass of 0.4 times, and disperse evenly. After reacting at room temperature for 6 h, the reaction solution is centrifuged, washed with water, and vacuum dried sequentially to obtain the final product.

[0034] The preparation method of the aminated spherical substrate is as follows: the nanosphere substrate is immersed in 90wt% ethanol aqueous solution at a mass ratio of 1:15, γ-aminopropyltrimethoxysilane at 25% by mass of ethanol aqueous solution is added, and the reaction is carried out at 65℃ for 4h. The reaction solution is then subjected to solid-liquid separation, washing and drying treatment to obtain the substrate.

[0035] The preparation method of the spherical substrate is as follows: 0.6 g / mL zirconium oxychloride aqueous solution and 0.3 g / mL cerium nitrate aqueous solution are mixed at a volume ratio of 2:1. Modified porous polymethyl methacrylate microspheres with a mass of 3 times that of zirconium oxychloride and anhydrous ethanol with an equal volume to the zirconium oxychloride aqueous solution are added sequentially. After ultrasonic dispersion until there are no obvious large solid particles, the reaction is carried out at 100℃ for 15 h. The reaction solution is filtered, and the filter cake is calcined at 550℃ for 5 h and then naturally cooled to room temperature to obtain the substrate.

[0036] The modified porous polymethyl methacrylate microspheres are prepared as follows: 3g of porous polymethyl methacrylate microspheres are ultrasonically dispersed in 200mL of deionized water, and then 6g of ethylenediamine is added. After reacting at 80℃ for 15h, the mixture is filtered, washed with water until neutral, washed four times with ethanol, and then vacuum dried at 50℃ to obtain the microspheres. Example 3:

[0037] The preparation method of the antibacterial coating for vehicle chassis provided in this embodiment is basically the same as that in Example 1, except that the specific proportions of the raw materials and the preparation methods of the composite additives are different. The specific proportions of the raw materials and the preparation methods of the composite additives in this embodiment are as follows: An antibacterial coating for vehicle chassis is made from the following components in parts by weight: 50 parts acrylic emulsion, 20 parts composite additives, 10 parts nano calcium carbonate, 5 parts silicon carbide, 4 parts carbon black, 2 parts bentonite, 3 parts nano zinc oxide, 3 parts dipropylene glycol butyl ether, 5 parts tetraphenylbisphenol-A-diphosphate, 1.2 parts zinc strontium phosphate, 1.5 parts iron oxide yellow, 0.5 parts 2-methyl-4-isothiazolin-3-one, 1 part BYK-331 leveling agent, 1.2 parts TEGO-270 wetting agent, 1 part BYK-A530 defoamer, 0.8 parts BYK-192 dispersant, and 20 parts water.

[0038] The preparation method of the composite additive is as follows: Step 1: Dissolve 2-phosphonobutane-1,2,4-tricarboxylic acid in deionized water to prepare an acid solution with a concentration of 5 wt%. Add 40% deacetylated chitin of 2-phosphonobutane-1,2,4-tricarboxylic acid and stir until fully dissolved. Heat the resulting mixture to 85°C and add formaldehyde at a volume of 2% of the acid solution. Reflux for 1 hour and then keep the mixture at this temperature for 5 hours. After the reaction is complete, rotary evaporate the reaction product to remove unreacted formaldehyde and water. The resulting concentrate is then vacuum dried and ground to obtain the modifier. Step 2: Add EDC at a mass of 0.4 times that of the modifier to an 8 wt% aqueous solution of the modifier, stir for 20 min, then add NHS in an equal molar amount to EDC and react for 2 h; then add aminated spherical substrate at a mass of 1 times that of the modifier and 0.5 times that of polyhexamethylene biguanide and disperse evenly, react at room temperature for 8 h, then centrifuge, wash with water and vacuum dry the reaction solution to obtain the final product.

[0039] The preparation method of the aminated spherical substrate is as follows: the nanosphere substrate is immersed in 90wt% ethanol aqueous solution at a mass ratio of 1:20, γ-aminopropyltrimethoxysilane at 30% by mass of ethanol aqueous solution is added, and the reaction is carried out at 70℃ for 3h. The reaction solution is then subjected to solid-liquid separation, washing and drying treatment to obtain the substrate.

[0040] The preparation method of the spherical substrate is as follows: 0.8 g / mL zirconium oxychloride aqueous solution and 0.3 g / mL cerium nitrate aqueous solution are mixed at a volume ratio of 2:1. Modified porous polymethyl methacrylate microspheres with a mass of 3 times that of zirconium oxychloride and anhydrous ethanol with an equal volume to the zirconium oxychloride aqueous solution are added sequentially. After ultrasonic dispersion until there are no obvious large solid particles, the reaction is carried out at 120℃ for 10 h. The reaction solution is filtered, and the filter cake is calcined at 600℃ for 4 h and then naturally cooled to room temperature to obtain the substrate.

[0041] The modified porous polymethyl methacrylate microspheres are prepared as follows: 5g of porous polymethyl methacrylate microspheres are ultrasonically dispersed in 200mL of deionized water, and then 8g of ethylenediamine is added. After reacting at 85℃ for 10h, the mixture is filtered, washed with water until neutral, washed four times with ethanol, and then vacuum dried at 60℃ to obtain the microspheres.

[0042] Comparative Example 1: The difference between this comparative example and Example 1 is that an equal amount of spherical substrate is used instead of composite additives in this comparative example.

[0043] Comparative Example 2: The difference between this comparative example and Example 1 is that polyhexamethylene biguanide was not used in the preparation of the composite additive in this comparative example.

[0044] Comparative Example 3: The difference between this comparative example and Example 1 is that this comparative example uses an equal amount of cerium dioxide microparticles and zirconium dioxide microparticles mixed powder with the same particle size as the spherical substrate (average particle size of 2.6-3.2 μm) to replace the composite additive; wherein, both cerium dioxide microparticles and zirconium dioxide microparticles are non-spherical microparticles, and the mass ratio of zirconium dioxide microparticles to non-spherical cerium dioxide microparticles is 2:1.

[0045] Performance testing: The antibacterial coatings for vehicle chassis prepared in Examples 1-3 and Comparative Examples 1-3 were diluted with deionized water to a viscosity of 20-35 seconds (Ford Cup 4, 25°C), and then sprayed onto the vehicle chassis. After baking at a plate temperature of 140-150°C for 30-45 minutes, the chassis samples coated with the coatings from Examples 1-3 and Comparative Examples 1-3 were obtained. The following performance tests were then conducted on each group, and the test results are recorded in Tables 1 and 2: 1. Film thickness: Tested according to GB / T 13452.2-2008 Coating thickness determination method.

[0046] 2. Adhesion: Tested according to GB / T 9286-2021 standard.

[0047] 3. Pencil hardness: GB / T 6739-2022 Coating hardness test method.

[0048] 4. Salt spray resistance: Tested according to GB / T 1771-2007 standard.

[0049] 5. Stone impact resistance (cycle): GB / T 1771-2007 Stone impact resistance test method.

[0050] 6. Impact resistance: Tested according to GB / T 1732-2020 standard.

[0051] 7. Antibacterial properties: Tested according to GB / T 21866-2008 standard.

[0052] 8. Abrasion resistance: Each group of test samples was tested with a Taber abrasion tester for 200 strokes, and then the wear of the paint film was observed.

[0053] Table 1

[0054] Table 2

[0055] By comparing and analyzing the relevant data in the table, it can be seen that the antibacterial coating prepared by this invention not only has excellent antibacterial properties but also excellent wear resistance, effectively improving the wear resistance of the vehicle chassis and reducing the probability of scratches. Simultaneously, it can resist microbial erosion in humid environments, significantly improving the durability and reliability of vehicle chassis protection and extending its service life to a certain extent. Therefore, this indicates that the antibacterial coating for vehicle chassis and its preparation method provided by this invention have a broader market prospect and are more suitable for widespread application.

[0056] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0057] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An antibacterial coating for vehicle chassis, characterized in that, It is made from the following components by weight: 30-50 parts acrylic emulsion, 10-20 parts composite additives, 6-10 parts nano calcium carbonate, 2-5 parts silicon carbide, 2-4 parts carbon black, 1-2 parts bentonite, 2-3 parts nano zinc oxide, 2-3 parts dipropylene glycol butyl ether, 3-5 parts tetraphenylbisphenol-A-diphosphate, 0.6-1.2 parts zinc strontium phosphate, 0.8-1.5 parts iron oxide yellow, 0.2-0.5 parts 2-methyl-4-isothiazolin-3-one, 0.5-1 part leveling agent, 0.6-1.2 parts wetting agent, 0.5-1 part defoamer, 0.3-0.8 parts dispersant, and 10-20 parts water.

2. The antibacterial coating for vehicle chassis according to claim 1, characterized in that, The preparation method of the composite additive is as follows: Step 1: Dissolve 2-phosphonobutane-1,2,4-tricarboxylic acid in deionized water to prepare an acid solution with a concentration of 3-5 wt%. Add 30-40% of deacetylated chitin to 2-phosphonobutane-1,2,4-tricarboxylic acid and stir until fully dissolved. Heat the resulting mixture to 80-85°C and add formaldehyde dropwise at a volume of 1-2% of the acid solution. Reflux for 1-2 hours and then maintain the temperature for 5-8 hours. After the reaction is complete, rotary evaporate the reaction product to remove unreacted formaldehyde and water. The resulting concentrate is then vacuum dried and ground to obtain the modifier. Step 2: Add EDC at a mass of 0.3-0.4 times that of the modifier to a 5-8 wt% aqueous solution of the modifier, stir for 10-20 min, then add NHS at a molar mass equal to that of EDC and react for 1-2 h; then add aminated spherical substrate at a mass of 0.5-1 times that of the modifier and polyhexamethylene biguanide at a mass of 0.2-0.5 times, and disperse evenly. After reacting at room temperature for 5-8 h, the reaction solution is centrifuged, washed with water, and vacuum dried sequentially to obtain the final product.

3. The antibacterial coating for vehicle chassis according to claim 2, characterized in that, The preparation method of the aminated spherical substrate is as follows: the nano-spherical substrate is immersed in an 85-90wt% ethanol aqueous solution at a mass ratio of 1:10-20, and 20-30% by mass of γ-aminopropyltrimethoxysilane is added to the ethanol aqueous solution. After reacting at 60-70℃ for 3-5h, the reaction solution is subjected to solid-liquid separation, washing and drying treatment in sequence to obtain the substrate.

4. The antibacterial coating for vehicle chassis according to claim 3, characterized in that, The method for preparing the spherical substrate is as follows: 0.5-0.8 g / mL of zirconium oxychloride aqueous solution and 0.2-0.3 g / mL of cerium nitrate aqueous solution are mixed at a volume ratio of 1-2:

1. Modified porous polymethyl methacrylate microspheres with a mass of 2-3 times that of zirconium oxychloride and anhydrous ethanol with a volume equal to that of the zirconium oxychloride aqueous solution are added sequentially. The mixture is ultrasonically dispersed until there are no obvious large solid particles, and then reacted at 90-120℃ for 10-20 h. The reaction solution is filtered, and the filter cake is calcined at 500-600℃ for 4-6 h, and then naturally cooled to room temperature to obtain the final product.

5. The antibacterial coating for vehicle chassis according to claim 4, characterized in that, The modified porous polymethyl methacrylate microspheres are prepared by ultrasonically dispersing 2-5g of porous polymethyl methacrylate microspheres in 100-200mL of deionized water, adding 5-8g of ethylenediamine, reacting at 75-85℃ for 10-15h, filtering, washing with water until neutral, washing with ethanol 3-4 times, and then vacuum drying at 40-60℃ to obtain the product.

6. The antibacterial coating for vehicle chassis according to claim 1, characterized in that: The leveling agent is any one of BYK-378, BASF EFKAFL 3772, or BYK-331.

7. The antibacterial coating for vehicle chassis according to claim 1, characterized in that: The wetting agent is at least one of TEGO-270 wetting agent and TEGO-265 wetting agent.

8. The antibacterial coating for vehicle chassis according to claim 1, characterized in that: The defoamer is any one of TEGO-8030, Dow Corning AFE-3168, or BYK-A530.

9. The antibacterial coating for vehicle chassis according to claim 1, characterized in that: The dispersant is any one of BYK-190, Dow 731A, and BYK-192.

10. A method for preparing an antibacterial coating for a vehicle chassis according to any one of claims 1-9, characterized in that, The process includes the following steps: weigh each component according to the formula, add each component to the mixing equipment for mixing and stirring, and after stirring evenly, use a sand mill to grind the resulting mixed slurry to a fineness of less than 10μm; then filter and fill the mixture to obtain the antibacterial coating for vehicle chassis.

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