Antibacterial coating and preparation method thereof

Abstract

The invention discloses an antibacterial coating which comprises a component A and a component B. The component A comprises the following raw materials in parts by weight: 40-60 parts of epoxy resin, 15-35 parts of polyamide resin, 5-10 parts of tea tree essential oil, 1-3 parts of di (2-ethylhexyl) phthalate, 1-2 parts of fumed silica, 1-2 parts of acrylate, 1-2 parts of sodium phosphate and 1-2 parts of polyvinyl ether. The component B comprises the following raw materials in parts by weight: 20-30 parts of modified nano zinc oxide, 40-60 parts of an antibacterial curing agent, 15-20 parts of butanol and 2-10 parts of acetone. The weight ratio of the component A to the component B is 8: (2-4), and the water-resistant coating is excellent in mechanical property, high in adhesive force and good in water resistance.

Description

Technical Field

[0001] The present invention relates to the field of coatings, and particularly to an antibacterial coating and a preparation method thereof.

[0002] A coating is a continuous film that is coated on the surface of an object to be protected or decorated and can form a firm attachment with the object to be coated. It is usually mainly composed of resin, or oil, or emulsion, with or without pigments and fillers, and corresponding additives are added, and it is a viscous liquid prepared with organic solvents or water. A coating with antibacterial properties is called an antibacterial coating. With the continuous improvement of people's living standards, people's requirements for the quality of life and hygiene are also getting higher and higher. How to effectively antibacterial and sterilize is a challenge posed by people for modern life. The antibacterial coating industry is still in the development stage. Solving the application process of antibacterial materials in coatings is a common topic facing the coating industry.

[0003] Antibacterial coatings are divided into two parts: one part is the bactericide, which plays a bactericidal role; the other part is the carrier. Currently, common antibacterial agents mainly include organic antibacterial agents, nano silver, and inorganic metal oxides. Among them, zinc oxide is widely used in antibacterial coatings because of its low cost and excellent bactericidal performance; the carrier is usually mainly some polymer polymers: polyurethane, epoxy resin, acrylic resin, or alkyd resin. Among them, epoxy resin has excellent properties such as strong adhesion and high hardness and is widely used in antibacterial coatings. The antibacterial agent forms a coating with the help of the carrier for construction. These two parts are indispensable and interdependent and are a whole. However, when the antibacterial agent is an inorganic metal oxide or nano silver, it cannot be compounded with the polymer inorganic substance alone and needs to rely on the action of a coupling agent.

[0004] The patent with the application number 201710416153.8 discloses a preparation method of modified nano zinc oxide. By using 3-aminopropyltriethoxysilane coupling agent to modify zinc oxide and applying it to coatings, the hardness and adsorption force of the coating film are enhanced. However, there are still the following deficiencies: this coupling agent has an amino hydrophilic group, which affects the water resistance of the coating. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides an antibacterial coating and a preparation method thereof.

[0006] The object of the present invention can be achieved by the following technical solutions; An antibacterial coating, comprising component A and component B; Component A includes the following raw materials in parts by weight: 40-60 parts of epoxy resin, 15-35 parts of polyamide resin, 5-10 parts of tea tree essential oil, 1-3 parts of bis(2-ethylhexyl) phthalate, 1-2 parts of fumed silica, 1-2 parts of acrylate, 1-2 parts of sodium phosphate, and 1-2 parts of polyethylene ether; Component B includes raw materials in the following parts by weight: 20 - 30 parts of modified nano - zinc oxide, 40 - 60 parts of antibacterial curing agent, 15 - 20 parts of butanol, 2 - 10 parts of acetone; The said antibacterial coating is made through the following steps; Step S1: Add epoxy resin and polyamide resin into a material barrel, add fumed silica, acrylate, sodium phosphate and polyethylene ether while stirring at a speed of 800 r / min. After the system is mixed evenly, disperse it at a speed of 2000 r / min for 20 min, grind it with a sand mill for 10 min, filter through a 200 - mesh sieve, and add tea tree essential oil and bis(2 - ethylhexyl) phthalate and stir at 500 r / min for 2 h to mix evenly to obtain Component A; Step S2: Mix butanol and acetone to form a mixed solution, then add modified nano - zinc oxide and antibacterial curing agent into the mixed solution, and stir at 500 r / min for 2 h to mix evenly to obtain Component B.

[0007] Furthermore, the said modified nano - zinc oxide is made through the following steps: By weight, put 10 - 15 parts of nano - zinc oxide into 90 - 110 parts of deionized water, ultrasonically disperse for 30 min, add 2 - 3 parts of polyfluoroamino - containing siloxane, heat to 50 - 60 °C and stir for 2 h, filter, then wash with 10 parts of absolute ethanol, and then dry at 30 - 40 °C for 3 h to obtain modified nano - zinc oxide; The molecular structural formula of the silane coupling agent is generally: Y - R - Si(OR) 3 , where Y represents the organic functional group end, Si - OR represents the silane oxy group end. The silane oxy group end is reactive to inorganic substances, and the organic functional group end has reactivity or compatibility with organic substances; after the silanol groups at the ends of the polyfluoroamino - containing siloxane are hydrolyzed, they undergo a bonding reaction with nano - zinc oxide, and the amino groups at the organic functional group ends and the antibacterial curing agent carry out synergistic curing on the complex of epoxy resin and polyamide resin, and react, making the connection between nano - zinc oxide and the polymer epoxy resin and polyamide complex more stable through the polyfluoroamino - containing siloxane coupling agent; the polyfluoroamino - containing siloxane coupling agent introduces fluorine elements on the basis of amino - siloxane, reduces the surface energy, and enhances the hydrophobic property.

[0008] Furthermore, the said polyfluoroamino - containing siloxane is made through the following steps: A1: Mix 1,1,2,2 - perfluorooctyltrimethoxysilane and sodium hydroxide evenly and heat to 60 - 70 °C, then slowly drop - add glycidol. After the dropping is completed, continue to react for 4 h to obtain intermediate a. The mass ratio of 1,1,2,2 - perfluorooctyltrimethoxysilane, sodium hydroxide and glycidol is 468:40 - 60:74 - 148; During the reaction, glycidol reacts with 1,1,2,2-perfluorooctyltrimethoxysilane in a one-to-one ratio according to molecular weight. The hydroxyl group in glycidol condenses with one C-F bond in 1,1,2,2-perfluorooctyltrimethoxysilane to form an ether bond, introducing an epoxy group. A2: Dissolve intermediate a and imidazole in acetonitrile, stir in a water bath at 45 - 55 °C for 2 h, remove the solvent by rotary evaporation, wash with acetonitrile, and then dry in vacuum at 30 - 40 °C for 5 h to obtain perfluorinated amino silicone. The weight ratio of intermediate a, imidazole, and acetonitrile is 522:68 - 136:700 - 800. During the reaction, intermediate a reacts with imidazole. The epoxy group in intermediate a undergoes a nucleophilic addition reaction with the amino group in imidazole, the epoxy group breaks, and a polymerization reaction occurs with the imidazole amino group to finally obtain the product.

[0009] Furthermore, the antibacterial curing agent is prepared through the following steps; B1: By weight, add 10 - 20 parts of chitosan to 40 - 60 parts of a 10% acetic acid solution by mass fraction to dissolve. Heat the resulting mixture to 50 - 70 °C and degrade it with ultrasonic waves for 25 - 35 h. Dropwise add a 5% sodium hydroxide solution by mass fraction to adjust the pH to 8 - 10 and continuously stir. After the solid precipitates, filter to obtain low-molecular-weight chitosan. B2: By weight, add 5 parts of low-molecular-weight chitosan and 1 - 2 parts of arginine to 20 parts of distilled water and stir to mix. Adjust the pH to 3 - 5 with a 5% hydrochloric acid solution by mass fraction. Subsequently, add 0.1 - 0.2 parts of 1-hydroxybenzotriazole and 0.1 - 0.2 parts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and react at 30 °C for 12 h. After the reaction, dropwise add a 5% sodium hydroxide solution by mass fraction to adjust the pH to 8 - 10 and continuously stir. After the solid precipitates, filter to obtain intermediate b. During the reaction, the amino group in low-molecular-weight chitosan undergoes an acylation reaction with the carboxyl group in arginine under the action of 1-hydroxybenzotriazole and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride to form intermediate b.

[0010] B3: Mix 2 - 3 parts of tea polyphenols and 5 - 6 parts of formaldehyde, introduce nitrogen, heat to 70 - 80 °C, stir at a speed of 300 - 500 r / min, react at a constant temperature for 3 h, then add intermediate b and continue to heat to 110 - 120 °C to liquefy intermediate b and keep it at a constant temperature for 2 h. Stop heating and stirring, cool to room temperature and discharge. Then carry out vacuum distillation at 110 - 120 °C for 2 h, with the distillation pressure of 0.10 - 0.20 kPa, remove the moisture, and obtain the antibacterial curing agent after cooling. In the first step of the reaction process, the phenolic hydroxyl groups in tea polyphenols undergo an aldol condensation reaction with formaldehyde at 70-80 °C to form benzaldehyde. In the second step of the reaction, benzaldehyde undergoes a ketimine reaction with the amino group in intermediate b at 110-120 °C to form an imine group, thus obtaining the desired antibacterial curing agent.

[0011] Advantages of the present invention: The present invention adopts an antibacterial coating with a complex of epoxy resin and polyamide resin cured by an antibacterial curing agent and a polyfluoroamino coupling agent as the matrix, tea tree essential oil and nano-zinc oxide as antibacterial substances, sodium phosphate as a dispersant, bis(2-ethylhexyl) phthalate as a plasticizer, fumed silica as an anti-settling agent, acrylate as a leveling agent, and polyethylene ether as an anti-foaming agent; The organic functional group ends of the polyfluoroamino siloxane coupling agent not only have amino groups to synergistically cure the complex of epoxy resin and polyamide resin with the antibacterial curing agent, react to form a network three-dimensional polymer, enhance the coating adhesion, but also introduce fluorine elements, reduce the surface energy of the coupling agent, and enhance the hydrophobic performance of the coating; The antibacterial curing agent is based on low-molecular chitosan, and forms a chitosan derivative through a series of reactions. It can not only be used as a curing agent to cure the complex of epoxy resin and polyamide resin, but also introduce guanidine groups and phenolic hydroxyl groups, which can change the cell activity and play an inhibitory role on bacteria. Specific embodiments

[0012] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Example 1

[0013] A modified nano-zinc oxide is prepared through the following steps; By weight, 10 parts of nano-zinc oxide are put into 90 parts of deionized water, ultrasonically dispersed for 30 min, 2 parts of polyfluoroamino siloxane are added, heated to 50 °C and stirred for 2 h, filtered, then washed with 10 parts of absolute ethanol, and then dried at 30 °C for 3 h to obtain modified nano-zinc oxide; The polyfluoroamino siloxane is prepared through the following steps; 1,1,2,2-Perfluorooctyltrimethoxysilane and sodium hydroxide are mixed evenly and heated to 60 °C, then glycidyl is slowly added dropwise. After the addition is complete, the reaction continues for 4 h to obtain intermediate a. The mass ratio of 1,1,2,2-perfluorooctyltrimethoxysilane, sodium hydroxide and glycidyl is 468:40:74; Dissolve intermediate a and imidazole in acetonitrile, stir in a water bath at 45 °C for 2 h, remove the solvent by rotary evaporation, wash with acetonitrile, and then dry in vacuum at 30 °C for 5 h to obtain polyfluoroamino silicone. The weight ratio of intermediate a, imidazole to acetonitrile is 522:68:700. Example 2

[0014] A modified nano-zinc oxide is prepared by the following steps; By weight, put 13 parts of nano-zinc oxide into 100 parts of deionized water, ultrasonically disperse for 30 min, add 2.5 parts of polyfluoroamino silicone, heat to 50 °C and stir for 2 h, filter, wash with 10 parts of absolute ethanol, and then dry at 30 °C for 3 h to obtain modified nano-zinc oxide; The polyfluoroamino silicone is prepared by the following steps; Mix 1,1,2,2-perfluorooctyltrimethoxysilane and sodium hydroxide evenly and heat to 65 °C, then slowly add glycidol dropwise. After the addition is complete, continue to react for 4 h to obtain intermediate a. The mass ratio of 1,1,2,2-perfluorooctyltrimethoxysilane, sodium hydroxide to glycidol is 468:60:111; Dissolve intermediate a and imidazole in acetonitrile, stir in a water bath at 50 °C for 2 h, remove the solvent by rotary evaporation, wash with acetonitrile, and then dry in vacuum at 30 °C for 5 h to obtain polyfluoroamino silicone. The weight ratio of intermediate a, imidazole to acetonitrile is 522:102:750. Example 3

[0015] A modified nano-zinc oxide is prepared by the following steps: By weight, put 15 parts of nano-zinc oxide into 110 parts of deionized water, ultrasonically disperse for 30 min, add 3 parts of polyfluoroamino silicone, heat to 60 °C and stir for 2 h, filter, wash with 10 parts of absolute ethanol, and then dry at 40 °C for 3 h to obtain modified nano-zinc oxide; The polyfluoroamino silicone is prepared by the following steps; Mix 1,1,2,2-perfluorooctyltrimethoxysilane and sodium hydroxide evenly and heat to 70 °C, then slowly add glycidol dropwise. After the addition is complete, continue to react for 4 h to obtain intermediate a. The mass ratio of 1,1,2,2-perfluorooctyltrimethoxysilane, sodium hydroxide to glycidol is 468:80:148; Dissolve intermediate a and imidazole in acetonitrile, stir in a water bath at 55 °C for 2 h, remove the solvent by rotary evaporation, wash with acetonitrile, and then dry in vacuum at 40 °C for 5 h to obtain polyfluoroamino silicone. The weight ratio of intermediate a, imidazole to acetonitrile is 522:136:800. Example 4

[0016] An antibacterial curing agent is prepared through the following steps; By weight, 10 parts of chitosan are added to 40 parts of a 10% acetic acid solution by mass fraction and dissolved. The obtained mixture is heated to 50 °C and ultrasonically degraded for 25 h. A 5% sodium hydroxide solution by mass fraction is added dropwise to adjust the pH to 8 and stirred continuously. After the solid precipitates, it is filtered to obtain low-molecular-weight chitosan; By weight, 5 parts of low-molecular-weight chitosan and 1 part of arginine are added to 20 parts of distilled water and stirred and mixed. The pH is adjusted to 3 with a 5% hydrochloric acid solution by mass fraction. Subsequently, 0.1 part of 1-hydroxybenzotriazole and 0.1 part of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride are added and reacted at 30 °C for 12 h. After the reaction is completed, a 5% sodium hydroxide solution by mass fraction is added dropwise to adjust the pH to 8 and stirred continuously. After the solid precipitates, it is filtered to obtain intermediate b; By weight, 2 parts of tea polyphenols and 5 parts of formaldehyde are mixed, nitrogen is introduced, the temperature is raised to 70 °C, and stirred at a speed of 300 r / min. The reaction is carried out at a constant temperature for 3 h. Then 10 parts of intermediate b are added and the temperature is further raised to 110 °C to liquefy intermediate b and keep it at a constant temperature for 2 h. Heating and stirring are stopped, and it is cooled to room temperature and discharged. Then it is subjected to vacuum distillation at 110 °C for 2 h, and the distillation pressure is 0.10 kPa to remove water. After cooling, an antibacterial curing agent is obtained. Example 5

[0017] An antibacterial curing agent is prepared through the following steps; By weight, 15 parts of chitosan are added to 50 parts of a 10% acetic acid solution by mass fraction and dissolved. The obtained mixture is heated to 60 °C and ultrasonically degraded for 30 h. A 5% sodium hydroxide solution by mass fraction is added dropwise to adjust the pH to 9 and stirred continuously. After the solid precipitates, it is filtered to obtain low-molecular-weight chitosan; By weight, 5 parts of low-molecular-weight chitosan and 1.5 parts of arginine are added to 20 parts of distilled water and stirred and mixed. The pH is adjusted to 4 with a 5% hydrochloric acid solution by mass fraction. Subsequently, 0.15 part of 1-hydroxybenzotriazole and 0.15 part of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride are added and reacted at 30 °C for 12 h. After the reaction is completed, a 5% sodium hydroxide solution by mass fraction is added dropwise to adjust the pH to 9 and stirred continuously. After the solid precipitates, it is filtered to obtain intermediate b; By weight, 2.5 parts of tea polyphenols and 5.5 parts of formaldehyde are mixed, nitrogen is introduced, the temperature is raised to 75 °C, and stirred at a speed of 400 r / min. The reaction is carried out at a constant temperature for 3 h. Then 10 parts of intermediate b are added and the temperature is further raised to 115 °C to liquefy intermediate b and keep it at a constant temperature for 2 h. Heating and stirring are stopped, and it is cooled to room temperature and discharged. Then it is subjected to vacuum distillation at 115 °C for 2 h, and the distillation pressure is 0.15 kPa to remove water. After cooling, an antibacterial curing agent is obtained. Example 6

[0018] An antibacterial curing agent is prepared through the following steps; By weight, 20 parts of chitosan are added to 60 parts of a 10% acetic acid solution by mass fraction and dissolved. The obtained mixture is heated to 70 °C and ultrasonically degraded for 35 h. A 5% sodium hydroxide solution by mass fraction is added dropwise to adjust the pH to 10 and continuously stirred. After the solid precipitates, filtration is carried out to obtain low-molecular-weight chitosan; By weight, 5 parts of low-molecular-weight chitosan and 2 parts of arginine are added to 20 parts of distilled water and stirred and mixed. A 5% hydrochloric acid solution by mass fraction is used to adjust the pH to 5. Subsequently, 0.2 part of 1-hydroxybenzotriazole and 0.2 part of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride are added and reacted at 30 °C for 12 h. After the reaction ends, a 5% sodium hydroxide solution by mass fraction is added dropwise to adjust the pH to 10 and continuously stirred. After the solid precipitates, filtration is carried out to obtain intermediate b; By weight, 3 parts of tea polyphenols and 6 parts of formaldehyde are mixed, nitrogen is introduced, the temperature is raised to 80 °C, and stirring is carried out at a speed of 500 r / min. The reaction is carried out at a constant temperature for 3 h. Then 10 parts of intermediate b are added and the temperature is further raised to 120 °C to liquefy intermediate b and keep it at a constant temperature for 2 h. Heating and stirring are stopped, and the mixture is cooled to room temperature and discharged. Then vacuum distillation is carried out at 120 °C for 2 h, and the distillation pressure is 0.20 kPa to remove moisture. After cooling, an antibacterial curing agent is obtained. Example 7

[0019] An antibacterial coating comprises component A and component B; Component A comprises the following raw materials by weight: 40 parts of epoxy resin, 15 parts of polyamide resin, 5 parts of tea tree essential oil, 1 part of bis(2-ethylhexyl) phthalate, 1 part of fumed silica, 1 part of acrylate, 1 part of sodium phosphate, and 1 part of polyethylene ether; Component B comprises the following raw materials by weight: 20 parts of the modified nano-zinc oxide obtained in Example 1, 40 parts of the antibacterial curing agent obtained in Example 4, 15 parts of butanol, and 2 parts of acetone; An antibacterial coating is prepared through the following steps; The epoxy resin and polyamide resin are added to a material barrel, and fumed silica, acrylate, sodium phosphate, and polyethylene ether are added under stirring at a speed of 800 r / min. After the system is mixed evenly, it is dispersed at a speed of 2000 r / min for 20 min, ground by a sand mill for 10 min, filtered through a 200-mesh sieve, and tea tree essential oil and bis(2-ethylhexyl) phthalate are added and stirred at 500 r / min for 2 h to mix evenly to obtain component A; Butanol and acetone are mixed to form a mixed solution, and then the modified nano-zinc oxide obtained in Example 1 and the antibacterial curing agent obtained in Example 4 are added to the mixed solution and stirred at 500 r / min for 2 h to mix evenly to obtain component B; Mix component A and component B in a weight ratio of 8:2 to obtain the antibacterial coating. Example 8

[0020] An antibacterial coating, comprising component A and component B; Component A comprises the following raw materials in parts by weight: 50 parts of epoxy resin, 25 parts of polyamide resin, 8 parts of tea tree essential oil, 2 parts of bis(2-ethylhexyl) phthalate, 1.5 parts of fumed silica, 1.5 parts of acrylate, 1.5 parts of sodium phosphate, and 1.5 parts of polyethylene ether; Component B comprises the following raw materials in parts by weight: 25 parts of the modified nano-zinc oxide obtained in Example 2, 50 parts of the antibacterial curing agent obtained in Example 5, 18 parts of butanol, and 7 parts of acetone; An antibacterial coating is prepared by the following steps; Add the epoxy resin and polyamide resin into a material barrel, add fumed silica, acrylate, sodium phosphate, and polyethylene ether while stirring at a speed of 800 r / min. After the system is mixed evenly, disperse it at a speed of 2000 r / min for 20 min, grind it with a sand mill for 10 min, filter it through a 200-mesh sieve, add tea tree essential oil and bis(2-ethylhexyl) phthalate, and stir at 500 r / min for 2 h to mix evenly to obtain component A; Mix butanol and acetone to form a mixed solution, and then add the modified nano-zinc oxide obtained in Example 2 and the antibacterial curing agent obtained in Example 5 into the mixed solution, and stir at 500 r / min for 2 h to mix evenly to obtain component B; Mix component A and component B in a weight ratio of 8:3 to obtain the antibacterial coating. Example 9

[0021] An antibacterial coating, comprising component A and component B; Component A comprises the following raw materials in parts by weight: 60 parts of epoxy resin, 35 parts of polyamide resin, 10 parts of tea tree essential oil, 3 parts of bis(2-ethylhexyl) phthalate, 2 parts of fumed silica, 2 parts of acrylate, 2 parts of sodium phosphate, and 2 parts of polyethylene ether; Component B comprises the following raw materials in parts by weight: 30 parts of the modified nano-zinc oxide obtained in Example 3, 60 parts of the antibacterial curing agent obtained in Example 6, 20 parts of butanol, and 10 parts of acetone; An antibacterial coating is prepared by the following steps; Add epoxy resin and polyamide resin into the material bucket, add fumed silica, acrylate, sodium phosphate and polyethylene ether while stirring at a speed of 800 r / min. After the system is mixed evenly, disperse it at a speed of 2000 r / min for 20 min, grind it with a sand mill for 10 min, filter it through a 200-mesh sieve, add tea tree essential oil and bis(2-ethylhexyl) phthalate, and stir at 500 r / min for 2 h to mix evenly to obtain Component A; Mix butanol and acetone to form a mixed solution, and then add the modified nano-zinc oxide obtained in Example 3 and the antibacterial curing agent obtained in Example 6 into the mixed solution, and stir at 500 r / min for 2 h to mix evenly to obtain Component B; Mix Component A and Component B according to a weight ratio of 8:4 to obtain the antibacterial coating.

[0022] The antibacterial coating prepared by the present invention is further subjected to an effect test, and the test results are as follows.

[0023] Test the relevant properties of the antibacterial coating prepared by the present invention according to the standard of GB / T16777-2008 "Test Methods for Building Waterproof Coatings". The antibacterial property test is carried out according to the JISZ2801 standard, and Escherichia coli is used as the test strain. The results are shown in Table 1.

[0024]

[0025] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology make various modifications or supplements to the described specific embodiments or use similar methods to replace them. As long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should all belong to the protection scope of the present invention.

Claims

1. An antibacterial coating, characterized in that: It includes component A and component B; Component A comprises the following raw materials in parts by weight: 40-60 parts of epoxy resin, 15-35 parts of polyamide resin, 5-10 parts of tea tree essential oil, 1-3 parts of di(2-ethylhexyl) phthalate, 1-2 parts of fumed silica, 1-2 parts of acrylate, 1-2 parts of sodium phosphate, and 1-2 parts of polyethylene ether; Component B includes the following raw materials in parts by weight: 20-30 parts of modified nano zinc oxide, 40-60 parts of antibacterial curing agent, 15-20 parts of butanol, and 2-10 parts of acetone; The antibacterial coating is prepared by the following steps: Step S1: adding epoxy resin and polyamide resin into a material barrel, adding fumed silica, acrylate, sodium phosphate and polyvinyl ether under stirring at a speed of 800 r / min, dispersing at a speed of 2000 r / min for 20 min after the system is mixed, grinding with a sand mill for 10 min, filtering with 200 mesh, adding tea tree essential oil and di(2-ethylhexyl) phthalate at 500 r / min and stirring for 2 h to mix evenly, to obtain component A; Step S2: butanol and acetone are mixed to prepare a mixed solution, and the modified nano zinc oxide and the antibacterial curing agent are added to the mixed solution, and stirred at 500 r / min for 2 h to obtain component B.

2. An antibacterial coating according to claim 1, characterized in that: The weight ratio of component A to component B is 8:2-4.

3. The antibacterial coating according to claim 1, characterized in that: The modified nano zinc oxide is prepared by the following steps: By weight, 10-15 parts of nano zinc oxide are added into 90-110 parts of deionized water, ultrasonically dispersed for 30 minutes, 2-3 parts of polyfluoroamino-containing siloxane are added, heated to 50-60°C and stirred for 2 hours, filtered, washed with 10 parts of anhydrous ethanol, and then dried at 30-40°C for 3 hours to obtain modified nano zinc oxide.

4. An antibacterial coating according to claim 3, characterized in that: The polyfluoroamino-containing siloxane is prepared by the following steps: A1: 1,1,2,2-perfluorooctyltrimethoxysilane and sodium hydroxide were mixed evenly and heated to 60-70°C, and then glycidol was slowly added dropwise. After the addition was completed, the reaction was continued for 4 hours to obtain intermediate a. The mass ratio of 1,1,2,2-perfluorooctyltrimethoxysilane, sodium hydroxide and glycidol was 468:40-60:74-148; A2: Dissolve intermediate a and imidazole in acetonitrile, stir in a water bath at 45-55°C for 2 hours, remove the solvent by rotary evaporation, wash with acetonitrile, and then vacuum dry at 30-40°C for 5 hours to obtain polyfluoroaminosiloxane. The weight ratio of intermediate a, imidazole and acetonitrile is 522:68-136:700-800.

5. The antibacterial coating according to claim 1, characterized in that: The antibacterial curing agent is prepared by the following steps; B1: By weight, 10-20 parts of chitosan are added to 40-60 parts of 10% acetic acid solution to dissolve, the obtained mixed solution is heated to 50-70°C, and ultrasonically degraded for 25-35 hours, 5% sodium hydroxide solution is added dropwise to adjust the pH to 8-10 and stirred continuously, and after solid precipitation, it is filtered to obtain low molecular weight chitosan; B2: By weight, 5 parts of low molecular weight chitosan and 1-2 parts of arginine are added to 20 parts of distilled water and stirred and mixed, and the pH is adjusted to 3-5 with a 5% hydrochloric acid solution, followed by adding 0.1-0.2 parts of a condensing agent and 0.1-0.2 parts of an amino coupling activated matrix to react at 30°C for 12 hours. After the reaction is completed, a 5% sodium hydroxide solution is added dropwise to adjust the pH to 8-10, and the mixture is stirred continuously. After the solid is precipitated, the intermediate b is obtained by filtering; B3: By weight, 2-3 parts of tea polyphenols and 5-6 parts of formaldehyde are mixed, nitrogen is introduced, the temperature is raised to 70-80°C, and the mixture is stirred at a speed of 300-500r / min. The reaction is carried out at a constant temperature for 3 hours. Then 10 parts of intermediate b are added, the temperature is continued to be raised to 110-120°C to liquefy the intermediate b and the temperature is kept constant for 2 hours. The heating and stirring are stopped, and the mixture is cooled to room temperature for discharge. Then, the mixture is subjected to reduced pressure distillation at 110-120°C for 2 hours with a distillation pressure of 0.10-0.20kPa. Water is removed and the antibacterial curing agent is obtained after cooling.

6. The antibacterial coating according to claim 5, characterized in that: The condensing agent is 1-hydroxybenzotriazole, and the amino coupling activation matrix is ​​1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride.

7. The method for preparing an antibacterial coating according to claim 1, characterized in that: The method comprises the following steps: Step S1: adding epoxy resin and polyamide resin into a material barrel, adding di(2-ethylhexyl) phthalate, fumed silica, acrylate, sodium phosphate and polyvinyl ether under stirring at a speed of 800 r / min, dispersing at a speed of 2000 r / min for 20 min after the system is mixed, grinding with a sand mill for 10 min, filtering with 200 mesh, adding tea tree essential oil and deionized water at 500 r / min and stirring for 2 h to mix them evenly, to obtain component A; Step S2: firstly mix butanol and acetone to prepare a mixed solution, then add the modified nano zinc oxide and the antibacterial curing agent into the mixed solution, and stir at 500 r / min for 2 h to evenly mix the materials to obtain component B.

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