Antibacterial coating and preparation method thereof

Abstract

The invention discloses an antibacterial coating and a preparation method thereof. The antibacterial coating is prepared from the following raw materials in parts by weight: 0.3 to 1 part of modified nano zinc oxide, 10 to 20 parts of ethanol, 80 to 90 parts of pentaerythritol triacrylate, 5 to 10 parts of modified isocyanate, 0.1 to 0.5 part of N-ethyl morpholine, 1 to 5 parts of photoinitiator and 1 to 10 parts of tackifier. Nano-zinc oxide is modified to enhance the antibacterial ability of the nano-zinc oxide, meanwhile, the nano-zinc oxide is not prone to polymerization in the oil paint, the good antibacterial ability of the nano-zinc oxide is played, isocyanate is modified to enable the nano-zinc oxide to have an antibacterial group, and the antibacterial group guanidyl is introduced to a polyurethane long chain, so that the nano-zinc oxide has a good antibacterial effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and specifically, relates to an antibacterial coating and a preparation method thereof. Background Art

[0002] With the development of technology, people have come to realize the threat of bacterial and viral infections to the human body. In daily life, coatings are widely used on furniture and means of transportation that come into daily contact with people. Therefore, the development of an efficient antibacterial coating has positive significance for preventing the spread of bacteria and viruses.

[0003] Antibacterial can generally be divided into active antibacterial and passive antibacterial. Active antibacterial generally involves adding antibacterial agents to the coating, and antibacterial agents are divided into natural, inorganic, and organic antibacterial agents. Passive antibacterial, such as forming a superhydrophobic or superhydrophilic coating, can reduce the attachment of bacteria to achieve antibacterial effects.

[0004] Natural antibacterial agents such as sorbic acid (2,4 - hexadienoic acid) are environmentally friendly, harmless to the human body, and non - irritating. However, they are greatly affected by factors such as temperature and pH, and have poor applicability in industry. Inorganic antibacterial agents are generally a class of antibacterial agents with metals such as silver, copper, titanium, and zinc as antibacterial substances. According to the antibacterial mechanism, they are divided into two major categories: photocatalytic type and metal type. Photocatalytic inorganic antibacterial agents include TiO 2 , ZnO, SiC, etc. Metal - type antibacterial agents are porous materials loaded with Ag + , Cu 2+ , Zn 2+ ions, as well as metal elements such as Ag, Cu, Zn and their oxides. Inorganic antibacterial agents generally have good thermal stability, low toxicity, and are easy to process. Their antibacterial properties have the advantages of broad - spectrum, slow - release, and long - lasting effects. Organic antibacterial agents include various categories such as acyl aniline, quaternary ammonium salts, pyridine, phenol, biguanide, and alcohol. Their advantages are low cost, fast onset speed, and strong antibacterial effect. Among inorganic antibacterial agents, nano - zinc oxide has a lower cost compared with Ag - based antibacterial agents. Compared with Cu - based antibacterial agents, it does not produce Cu 2+ with high toxicity. At the same time, compared with Ti - based antibacterial agents that can only produce antibacterial effects under light conditions, nano - zinc oxide has both photocatalytic and metal antibacterial mechanisms and is applicable to various situations. It is an ideal antibacterial agent for coatings. However, the antibacterial performance of nano - zinc oxide itself is worse than that of Ag - and Cu - based antibacterial agents, and its antibacterial effect needs to be improved. Moreover, nano - zinc oxide is hydrophilic and is prone to polymerization in oil - based coatings, unable to play an effective antibacterial role.

[0005] The addition of isocyanate to pentaerythritol triacrylate mainly reacts with the hydroxyl groups on pentaerythritol triacrylate to improve the overall adhesion, heat resistance, and hardness of the coating, and does not have antibacterial ability. Summary of the Invention

[0006] To solve the above problems, the present invention provides an antibacterial coating and a preparation method thereof.

[0007] The object of the present invention can be achieved by the following technical solutions: An antibacterial coating, comprising the following components: 0.3 - 1 part of modified nano - zinc oxide, 10 - 20 parts of ethanol, 80 - 90 parts of pentaerythritol triacrylate, 5 - 10 parts of modified isocyanate, 0.1 - 0.5 part of N - ethylmorpholine, 1 - 5 parts of photoinitiator and 1 - 10 parts of tackifier; An antibacterial coating is prepared by the following steps: S1: Add the modified nano - zinc oxide into ethanol, stir at 200 - 300 rpm and ultrasonically disperse for 20 min to obtain a suspension for standby; S2: Add pentaerythritol triacrylate, modified isocyanate and N - ethylmorpholine into a reaction vessel, heat to 70 - 80 °C, stir at 200 - 300 rpm for 30 - 40 min to obtain a mixed solution; S3: Slowly add the suspension, photoinitiator and tackifier into the mixed solution, heat to 70 - 80 °C, stir at 200 - 300 rpm for 3 - 4 h, and the required antibacterial coating can be obtained after cooling.

[0008] The modified nano - zinc oxide is prepared by the following method: Put nano - zinc oxide into absolute ethanol, magnetically stir for 10 min and ultrasonically disperse for 20 min to obtain a nano - zinc oxide dispersion liquid, with a stirring rate of 100 - 150 rpm. Add a modified silane coupling agent to the nano - zinc oxide dispersion liquid, heat in a water bath to 75 - 78 °C and react for 1 - 1.5 h. Then centrifuge the dispersion liquid to obtain a precipitate, and vacuum - dry the obtained precipitate at 50 °C for 12 h to obtain modified nano - zinc oxide. The dosage ratio of nano - zinc oxide, absolute ethanol and modified coupling agent is 0.5 - 1 kg: 8 - 9 kg: 0.05 - 0.1 kg; The modified silane coupling agent has silicon as the center, and on both sides, there are two groups with different properties that can connect inorganic and organic matrices. Among them, the inorganic group combines with the surface functional groups of zinc oxide to form a stable chemical bond, combines the organic group with antibacterial and hydrophobic effects with zinc oxide, modifies zinc oxide, improves its antibacterial performance and hydrophobic ability, and makes it not easy to polymerize in the oil - based coating.

[0009] Furthermore, the modified silane coupling agent is synthesized by the following steps: A1: Add 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione into carbon tetrachloride, stir at 200 - 300 rpm and heat to 30 - 40 °C. Then add thionyl chloride and react for 1 - 2 h. Next, add a sodium hypochlorite solution with a mass percentage concentration of 1%, and react for another 1 - 2 h. Then, conduct vacuum drying at 60 °C to obtain intermediate a. The dosage ratio of 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione, carbon tetrachloride, thionyl chloride, and sodium hypochlorite solution is 1 mol : 10 - 15 mol : 1 - 1.5 mol : 15 - 20 kg; During the reaction process, 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione reacts with thionyl chloride in a 1:1 ratio. The chlorine in thionyl chloride replaces the hydroxyl group in 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione. Then, add a sodium hypochlorite solution to halogenate it to obtain intermediate a, where the N-haloamine group has good antibacterial and hydrophobic properties. The specific structure is as follows;

[0010] A2: Add intermediate a and (N,N-dimethyl-3-aminopropyl)trimethoxysilane into n-butanol, stir at 200 - 300 rpm, and react under the conditions of a microwave power of 600 W and a temperature of 130 °C for 3 - 4 h. Then, perform rotary evaporation under reduced pressure and conduct vacuum drying at 50 °C for 12 h to obtain a modified silane coupling agent. The dosage ratio of intermediate a, (N,N-dimethyl-3-aminopropyl)trimethoxysilane, and n-butanol is 1 mol : 1 mol : 2 - 3 mol.

[0011] During the reaction process, intermediate a reacts with (N,N-dimethyl-3-aminopropyl)trimethoxysilane in a 1:1 ratio. In a microwave reactor, the chloropropyl group of intermediate a combines with the N,N-dimethyl-3-aminopropyl part at the end of (N,N-dimethyl-3-aminopropyl)trimethoxysilane to form a quaternary ammonium salt structure with good antibacterial effects.

[0012]

[0013] Furthermore, the modified isocyanate is prepared by the following method: B1: Add N,N-di-BOC-S-methylisothiourea into dichloromethane, stir at 150 - 200 rpm and add ethanolamine, and react at a temperature of 25 - 30 °C for 18 - 24 h. Cool and filter to obtain a guanidine intermediate. The dosage ratio of N,N-di-BOC-S-methylisothiourea, dichloromethane, and ethanolamine is 1 mol : 5 - 10 mol : 1 - 1.2 mol; During the reaction, N,N-di-BOC-S-methylisothiourea undergoes a nucleophilic substitution reaction with ethanolamine to form a guanidyl group, which has good antibacterial effects, and at the same time, a hydroxyl group is introduced. The specific structure is as follows:

[0014] B2: Add phenyl isocyanate-1,3,5-triisocyanate to dichloromethane, stir at 150 - 200 rpm, and add stannous octoate and the guanidyl intermediate. React at a temperature of 35 - 40 °C for 12 - 14 h, perform rotary evaporation under vacuum and filter. Wash the precipitated solid 5 times with petroleum ether to obtain the modified isocyanate. The dosage ratio of phenyl isocyanate-1,3,5-triisocyanate, dichloromethane, stannous octoate, and the guanidyl intermediate is 1 mol : 5 - 10 mol : 0.3 - 0.5 mol : 1 - 1.3 mol.

[0015] During the reaction, the isocyanate group on phenyl isocyanate-1,3,5-triisocyanate undergoes an addition reaction with the hydroxyl group in the guanidyl intermediate to obtain the modified isocyanate.

[0016]

[0017] The photosensitizer is at least one of 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, methyl benzoylformate, or 2-dimethylamino-2-benzyl-1-[4-(4-morpholinyl)phenyl]-1-butanone.

[0018] The tackifier is at least one of ketone-aldehyde resin, xylene-formaldehyde resin, or C5 petroleum resin.

[0019] The beneficial effects of the present invention: The present invention prepares an antibacterial coating. Among them, the antibacterial effect of nano-zinc oxide is weaker than that of conventional antibacterial agents. By combining a modified silane coupling agent with nano-zinc oxide, its antibacterial ability is enhanced. At the same time, due to the organic groups on the coupling agent, it is not easy to polymerize in the oil-based coating, and the good antibacterial ability of nano-zinc oxide is exerted. The modified silane coupling agent is based on (N,N-dimethyl-3-aminopropyl)trimethoxysilane and reacts with intermediate a in a microwave reactor to generate a quaternary ammonium group, and at the same time introduce an N-haloamine group. The quaternary ammonium group and the N-haloamine group have good active antibacterial ability and also have a certain hydrophobic ability to reduce the attachment of bacteria to form a passive antibacterial effect; isocyanate usually does not have antibacterial groups when used in coatings. Modify isocyanate to make it carry antibacterial groups. N,N-di-BOC-S-methylisothiourea undergoes a nucleophilic substitution reaction with ethanolamine to generate a guanidine group, and at the same time the introduced hydroxyl group reacts with 1,3,5-triisocyanatobenzene in a one-to-one ratio to obtain a modified isocyanate. The modified isocyanate polymerizes with pentaerythritol triacrylate under the action of a catalyst, and an antibacterial group guanidine is introduced into the polyurethane long chain, which has a good antibacterial effect. Detailed implementation mode

[0020] 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Example 1

[0021] A modified nano-zinc oxide is prepared by the following steps: Put nano-zinc oxide into absolute ethanol, magnetically stir for 10 min and ultrasonically disperse for 20 min to obtain a nano-zinc oxide dispersion. The stirring rate is 130 rpm. Add a modified silane coupling agent to the nano-zinc oxide dispersion, heat it in a water bath to 78 °C and react for 1.5 h. Then centrifuge the dispersion to obtain a precipitate, and then vacuum dry the obtained precipitate at 50 °C for 12 h to obtain modified nano-zinc oxide. The dosage ratio of nano-zinc oxide, absolute ethanol and modified coupling agent is 0.5 kg: 8 kg: 0.05 kg; The modified coupling agent is prepared by the following steps: 1-(3-Hydroxypropyl)-1,3,5-triazine-2,4,6-trione was added to carbon tetrachloride, stirred at 200 rpm and heated to 30 °C. Then thionyl chloride was added and the reaction was carried out for 2 h. Then a sodium hypochlorite solution with a mass percentage concentration of 1% was added, and after reacting for another 2 h, it was dried under vacuum at 60 °C to obtain intermediate a. The dosage ratio of 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione, carbon tetrachloride, thionyl chloride and sodium hypochlorite solution was 1 mol: 10 mol: 1 mol: 15 kg; Intermediate a and (N,N-dimethyl-3-aminopropyl)trimethoxysilane were added to n-butanol, stirred at 200 rpm, and reacted under the conditions of a microwave power of 600 W and a temperature of 130 °C for 4 h. Then it was rotary evaporated under reduced pressure and further dried under vacuum at 50 °C for 12 h to obtain a modified silane coupling agent. The dosage ratio of intermediate a, (N,N-dimethyl-3-aminopropyl)trimethoxysilane and n-butanol was 1 mol: 1 mol: 2 mol. Example 2

[0022] A modified nano-zinc oxide is prepared by the following steps: Nano-zinc oxide was put into absolute ethanol, magnetically stirred for 10 min and ultrasonically dispersed for 20 min to obtain a nano-zinc oxide dispersion. The stirring rate was 150 rpm. A modified silane coupling agent was added to the nano-zinc oxide dispersion, and the reaction was carried out at 75 °C in a water bath for 1.5 h. Then the dispersion was centrifuged to obtain a precipitate, and the obtained precipitate was dried under vacuum at 50 °C for 12 h to obtain modified nano-zinc oxide. The dosage ratio of nano-zinc oxide, absolute ethanol and modified coupling agent was 1 kg: 9 kg: 0.1 kg; The modified coupling agent is prepared by the following steps: 1-(3-Hydroxypropyl)-1,3,5-triazine-2,4,6-trione was added to carbon tetrachloride, stirred at 300 rpm and heated to 40 °C. Then thionyl chloride was added and the reaction was carried out for 1 h. Then a sodium hypochlorite solution with a mass percentage concentration of 1% was added, and after reacting for another 1 h, it was dried under vacuum at 60 °C to obtain intermediate a. The dosage ratio of 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione, carbon tetrachloride, thionyl chloride and sodium hypochlorite solution was 1 mol: 15 mol: 1.5 mol: 20 kg; Intermediate a and (N,N-dimethyl-3-aminopropyl)trimethoxysilane were added to n-butanol, stirred at 300 rpm, and reacted under the conditions of a microwave power of 600 W and a temperature of 130 °C for 3 h. Then it was rotary evaporated under reduced pressure and further dried under vacuum at 50 °C for 12 h to obtain a modified silane coupling agent. The dosage ratio of intermediate a, (N,N-dimethyl-3-aminopropyl)trimethoxysilane and n-butanol was 1 mol: 1 mol: 3 mol. Example 3

[0023] A modified nano-zinc oxide is prepared by the following steps: Put nano-zinc oxide into absolute ethanol, stir magnetically for 10 min and disperse ultrasonically for 20 min to obtain a nano-zinc oxide dispersion. The stirring rate is 100 rpm. Add a modified silane coupling agent to the nano-zinc oxide dispersion, heat it in a water bath to 77 °C and react for 1.3 h. Then centrifuge the dispersion to obtain a precipitate, and vacuum-dry the obtained precipitate at 50 °C for 12 h to obtain the modified nano-zinc oxide. The dosage ratio of nano-zinc oxide, absolute ethanol and the modified coupling agent is 0.8 kg: 8.5 kg: 0.08 kg; The modified coupling agent is prepared by the following steps: Add 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione into carbon tetrachloride, stir at 250 rpm and heat to 35 °C. Then add thionyl chloride and react for 1.5 h. Then add a sodium hypochlorite solution with a mass percentage concentration of 1%, react for another 1.5 h, and vacuum-dry at 60 °C to obtain intermediate a. The dosage ratio of 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione, carbon tetrachloride, thionyl chloride and the sodium hypochlorite solution is 1 mol: 13 mol: 1.3 mol: 18 kg; Add intermediate a and (N,N-dimethyl-3-aminopropyl)trimethoxysilane into n-butanol, stir at 250 rpm, and react under the conditions of a microwave power of 600 W and a temperature of 130 °C for 3.5 h. Then carry out rotary evaporation under reduced pressure and vacuum-dry at 50 °C for 12 h to obtain the modified silane coupling agent. The dosage ratio of intermediate a, (N,N-dimethyl-3-aminopropyl)trimethoxysilane and n-butanol is 1 mol: 1 mol: 2.5 mol. Example 4

[0024] A modified isocyanate is prepared by the following steps: Add N,N-di-BOC-S-methylisothiourea into dichloromethane, stir at 150 rpm and add ethanolamine, and react at a temperature of 25 °C for 24 h. Cool and filter to obtain a guanidine intermediate. The dosage ratio of N,N-di-BOC-S-methylisothiourea, dichloromethane and ethanolamine is 1 mol: 5 mol: 1 mol; Add 1,3,5-triisocyanatobenzene into dichloromethane, stir at 150 rpm and add stannous octoate and the guanidine intermediate, and react at a temperature of 35 °C for 14 h. Carry out rotary evaporation under vacuum and filter. Wash the precipitated solid with petroleum ether 5 times to obtain the modified isocyanate. The dosage ratio of 1,3,5-triisocyanatobenzene, dichloromethane, stannous octoate and the guanidine intermediate is 1 mol: 5 mol: 0.3 mol: 1 mol. Example 5

[0025] A modified isocyanate is prepared through the following steps: Add N,N-di-BOC-S-methylisothiourea into dichloromethane, stir at 200 rpm and add ethanolamine, react at 30 °C for 18 h, cool and filter to obtain a guanidine intermediate. The dosage ratio of N,N-di-BOC-S-methylisothiourea, dichloromethane and ethanolamine is 1 mol:10 mol:1.2 mol; Add 1,3,5-triisocyanatobenzene into dichloromethane, stir at 200 rpm and add stannous octoate and the guanidine intermediate, react at 40 °C for 12 h, perform rotary evaporation under vacuum and filter. Wash the precipitated solid with petroleum ether 5 times to obtain the modified isocyanate. The dosage ratio of 1,3,5-triisocyanatobenzene, dichloromethane, stannous octoate and the guanidine intermediate is 1 mol:10 mol:0.3 - 0.5 mol:1.3 mol. Example 6

[0026] A modified isocyanate is prepared through the following steps: Add N,N-di-BOC-S-methylisothiourea into dichloromethane, stir at 180 rpm and add ethanolamine, react at 28 °C for 22 h, cool and filter to obtain a guanidine intermediate. The dosage ratio of N,N-di-BOC-S-methylisothiourea, dichloromethane and ethanolamine is 1 mol:8 mol:1.1 mol; Add 1,3,5-triisocyanatobenzene into dichloromethane, stir at 180 rpm and add stannous octoate and the guanidine intermediate, react at 38 °C for 13 h, perform rotary evaporation under vacuum and filter. Wash the precipitated solid with petroleum ether 5 times to obtain the modified isocyanate. The dosage ratio of 1,3,5-triisocyanatobenzene, dichloromethane, stannous octoate and the guanidine intermediate is 1 mol:8 mol:0.3 - 0.5 mol:1.2 mol. Example 7

[0027] An antibacterial coating comprises the following components: 0.3 part of the modified nano zinc oxide obtained in Experimental Example 1, 10 parts of ethanol, 80 parts of pentaerythritol triacrylate, 5 parts of the modified isocyanate obtained in Experimental Example 4, 0.1 part of N-ethylmorpholine, 1 part of a photoinitiator and 1 part of a tackifier; An antibacterial coating is prepared through the following steps: S1: Add the modified nano zinc oxide into ethanol, stir at 200 rpm and perform ultrasonic dispersion for 20 min to obtain a suspension for standby; S2: Add pentaerythritol triacrylate, modified isocyanate and N-ethylmorpholine into a reaction vessel, heat to 70 °C, stir at 200 rpm for 40 min to obtain a mixed solution; S3: Slowly add the suspension, photoinitiator and tackifier into the mixed solution, heat to 70 °C, stir at 200 rpm for 4 h, and the required antibacterial coating can be obtained after cooling. Example 8

[0028] An antibacterial coating, comprising the following components: 1 part of the modified nano-zinc oxide obtained in Experimental Example 1, 20 parts of ethanol, 90 parts of pentaerythritol triacrylate, 10 parts of the modified isocyanate obtained in Experimental Example 4, 0.5 part of N-ethylmorpholine, 5 parts of photoinitiator and 10 parts of tackifier; An antibacterial coating is prepared by the following steps: S1: Add the modified nano-zinc oxide into ethanol, stir at 300 rpm and ultrasonically disperse for 20 min to obtain a suspension for standby; S2: Add pentaerythritol triacrylate, modified isocyanate and N-ethylmorpholine into a reaction vessel, heat to 80 °C, stir at 300 rpm for 30 min to obtain a mixed solution; S3: Slowly add the suspension, photoinitiator and tackifier into the mixed solution, heat to 80 °C, stir at 300 rpm for 3 h, and the required antibacterial coating can be obtained after cooling. Example 9

[0029] An antibacterial coating, comprising the following components: 0.6 part of the modified nano-zinc oxide obtained in Experimental Example 1, 15 parts of ethanol, 85 parts of pentaerythritol triacrylate, 8 parts of the modified isocyanate obtained in Experimental Example 4, 0.3 part of N-ethylmorpholine, 3 parts of photoinitiator and 6 parts of tackifier; An antibacterial coating is prepared by the following steps: S1: Add the modified nano-zinc oxide into ethanol, stir at 260 rpm and ultrasonically disperse for 20 min to obtain a suspension for standby; S2: Add pentaerythritol triacrylate, modified isocyanate and N-ethylmorpholine into a reaction vessel, heat to 75 °C, stir at 260 rpm for 35 min to obtain a mixed solution; S3: Slowly add the suspension, photoinitiator and tackifier into the mixed solution, heat to 75 °C, stir at 260 rpm for 3.5 h, and the required antibacterial coating can be obtained after cooling.

[0030] Comparative Example 1 The comparative example is a commercially available antibacterial coating.

[0031] Comparative Example 2 Compared with Example 9, the modified nano-zinc oxide was replaced with commercially available nano-zinc oxide, and the other steps were exactly the same as those in Example 9 to prepare an antibacterial coating.

[0032] Comparative Example 3 Compared with Example 9, the modified isocyanate was replaced with commercially available toluene diisocyanate, and the other steps were exactly the same as those in Example 9 to prepare an antibacterial coating.

[0033] The antibacterial coatings prepared by the present invention were further subjected to effect detection, and the detection results are shown in the following table:

[0034] It can be seen from the detection results in the table that there are no significant differences in the basic properties such as hardness, impact strength, flexibility, hiding power, adhesion, tensile strength, water resistance and alcohol resistance between Examples 7, 8 and 9 and Comparative Example 1, which can meet the basic use requirements of the coating; the antibacterial efficiency and antibacterial durability of Examples 7, 8 and 9 are improved compared with Comparative Example 1; it can be seen from the comparison between Example 9 and Comparative Examples 2 and 3 that the antibacterial durability is greatly improved under the combined action of the modified nano-zinc oxide and the modified isocyanate.

[0035] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present 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 the claims of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. An antibacterial coating, characterized in that: The composition comprises the following raw materials in parts by weight: 0.3-1 parts of modified nano zinc oxide, 10-20 parts of ethanol, 80-90 parts of pentaerythritol triacrylate, 5-10 parts of modified isocyanate, 0.1-0.5 parts of N-ethylmorpholine, 1-5 parts of photoinitiator and 1-10 parts of tackifier; The modified nano zinc oxide is prepared by the following steps: Nano zinc oxide is put into anhydrous ethanol, magnetically stirred for 10 minutes and ultrasonically dispersed for 20 minutes to obtain a nano zinc oxide dispersion, the stirring rate is 100-150rpm, a modified silane coupling agent is added to the nano zinc oxide dispersion, heated to 75-78°C in a water bath for reaction for 1-1.5 hours, and then the dispersion is centrifuged to obtain a precipitate, and the obtained precipitate is vacuum dried at 50°C for 12 hours to obtain modified nano zinc oxide, and the amount ratio of nano zinc oxide, anhydrous ethanol and modified coupling agent is 0.5-1kg:8-9kg:0.05-0.1kg.

2. An antibacterial coating according to claim 1, characterized in that: The modified silane coupling agent is prepared by the following steps: A1: Add 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione to carbon tetrachloride, stir at 200-300 rpm and heat to 30-40°C, then add thionyl chloride, react for 1-2 hours, then add sodium hypochlorite solution, react for 1-2 hours, and vacuum dry at 60°C to obtain intermediate a; A2: Add intermediate a and (N,N-dimethyl-3-aminopropyl)trimethoxysilane into n-butanol, stir at 200-300 rpm, and react for 3-4 hours at a microwave power of 600 W and a temperature of 130°C, then perform rotary evaporation under reduced pressure, and then vacuum dry at 50°C for 12 hours to obtain a modified silane coupling agent.

3. The antibacterial coating according to claim 1, characterized in that: In the step A1, the usage ratio of 1-(3-hydroxypropyl)-1,3,5-triazine-2,4,6-trione, carbon tetrachloride, thionyl chloride and sodium hypochlorite solution is 1 mol: 10-15 mol: 1-1.5 mol: 15-20 kg, and the mass percentage concentration of the sodium hypochlorite solution is 1%.

4. The antibacterial coating according to claim 1, characterized in that: In the step A2, the ratio of the intermediate a, (N,N-dimethyl-3-aminopropyl)trimethoxysilane and n-butanol is 1 mol: 1 mol: 2-3 mol.

5. The antibacterial coating according to claim 1, characterized in that: The modified isocyanate is prepared by the following steps: B1: Add N, N-di-BOC-S-methylisothiourea to dichloromethane, stir at 150-200 rpm and add ethanolamine, react at 25-30°C for 18-24h, cool and filter to obtain a guanidine intermediate; B2: Add 1,3,5-phenyl triisocyanate to dichloromethane, stir at 150-200 rpm and add stannous octoate and guanidine intermediate, react at 35-40°C for 12-14h, vacuum evaporate and filter, wash the precipitated solid with petroleum ether 5 times to obtain modified isocyanate.

6. The antibacterial coating according to claim 1, characterized in that: In the step B1, the usage ratio of N,N-di-BOC-S-methylisothiourea, dichloromethane and ethanolamine is 1 mol: 5-10 mol: 1-1.2 mol.

7. The antibacterial coating according to claim 1, characterized in that: In the step B2, the ratio of 1,3,5-phenyl triisocyanate, dichloromethane, stannous octoate and guanidine intermediate is 1 mol: 5-10 mol: 0.3-0.5 mol: 1-1.3 mol.

8. The antibacterial coating according to claim 1, characterized in that: The photosensitive initiator is at least one of 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, methyl benzoylformate or 2-dimethylamino-2-benzyl-1-[4-(4-morpholinyl)phenyl]-1-butanone.

9. The antibacterial coating according to claim 1, characterized in that: The tackifier is at least one of ketone-aldehyde resin, xylene formaldehyde resin or C5 petroleum resin.

10. The method for preparing an antibacterial coating according to claim 1, characterized in that: The steps include: S1: Add the modified nano zinc oxide into ethanol, stir at 200-300 rpm and perform ultrasonic dispersion for 20 min to obtain a suspension for use; S2: adding pentaerythritol triacrylate, modified isocyanate and N-ethylmorpholine into a reaction container, heating to 70-80° C., stirring at 200-300 rpm for 30-40 min to obtain a mixed solution; S3: slowly add the suspension, photoinitiator and tackifier into the mixed solution, heat to 70-80°C, stir at 200-300 rpm for 3-4 hours, and after cooling, the desired antibacterial coating can be obtained.

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