Antibacterial acrylic resin composite coating and preparation process thereof

Abstract

The invention provides an antibacterial acrylic resin composite coating and a preparation process thereof, and belongs to the technical field of coating preparation. The preparation process comprises the following steps: preparing the antibacterial modifier; preparing modified acrylate; preparing modified zinc oxide; and preparing the composite coating. The acrylic ester is modified by the antibacterial modifier to improve the overall antibacterial effect of the modified acrylic ester, and then the zinc oxide synergistically modified by the HMDS and the hydroxyl silicone oil is added to further improve the antibacterial effect of the composite coating.

Description

Technical Field

[0001] The present invention relates to the technical field of coating preparation, and particularly relates to an antibacterial acrylic resin composite coating and a preparation process thereof. Background Art

[0002] In the field of coating technology, acrylic resin coatings are widely used in fields such as architectural decoration, medical devices, and food packaging due to their excellent weather resistance, light and color retention properties, and film-forming properties. With the improvement of public health safety awareness and the increasing demand for long-term antibacterial protection, traditional acrylic resin coatings are difficult to meet the usage requirements in scenarios where bacteria are likely to grow, such as hospital walls, kitchens, and bathrooms, due to the lack of antibacterial functions.

[0003] Existing antibacterial coatings mostly achieve antibacterial effects by adding metal antibacterial agents such as silver-based and copper-based ones or organic antibacterial agents such as quaternary ammonium salts. However, metal ions are prone to migration and have poor compatibility with the acrylic resin matrix, which easily leads to uneven dispersion, reducing the physical and mechanical properties and antibacterial stability of the coating. Organic small molecule antibacterial agents have defects such as easy loss and insufficient antibacterial long-term effectiveness.

[0004] Therefore, we have proposed an antibacterial acrylic resin composite coating with both high antibacterial properties and good compatibility and a preparation process thereof. Summary of the Invention

[0005] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide an antibacterial acrylic resin composite coating and a preparation process thereof.

[0006] An antibacterial acrylic resin composite coating, the composite coating comprises the following components: 60 - 70 parts by weight of modified acrylate emulsion, 0.1 - 0.3 parts by weight of defoamer, 0.2 - 0.5 parts by weight of leveling agent, 3 - 5 parts by weight of curing agent, 0.5 - 1 part by weight of thickener, and pre-dispersed modified zinc oxide slurry; The pre-dispersed modified zinc oxide slurry comprises 15 - 20 parts by weight of modified zinc oxide, 1 - 2 parts by weight of dispersant, and 10 - 13 parts by weight of deionized water; The modified acrylate emulsion is copolymerized from an antibacterial modifier, azobisisobutyramidine hydrochloride, cetyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether, benzyl methacrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, and glycidyl methacrylate; The antibacterial modifier is obtained by reacting dimethylaminoethyl methacrylate, hexadecyl bromide, and 2,6-di-tert-butyl-p-cresol; The modified zinc oxide is obtained by synergistically modifying with coupling agent HMDS and hydroxy silicone oil.

[0007] A preparation process of an antibacterial acrylic resin composite coating, comprising the following steps: S1: Preparation of Antibacterial Modifier Add 10 - 12 parts by weight of dimethylaminoethyl methacrylate, 18.8 - 19.3 parts by weight of cetyl bromide, and 0.01 - 0.02 parts by weight of 2,6 - di - tert - butyl - p - cresol into 20 - 30 parts by weight of acetone. After reaction, add ether, then filter, wash, and dry to obtain the antibacterial modifier; S2: Preparation of Modified Acrylate Add the antibacterial modifier, cetyltrimethylammonium chloride, and fatty alcohol polyoxyethylene ether into deionized water, then add benzyl methacrylate, n - butyl acrylate, and azodiisobutyramidine hydrochloride solution to obtain a mixed solution. Mix benzyl methacrylate, n - butyl acrylate, 2 - hydroxyethyl acrylate, and glycidyl methacrylate to obtain a mixture. Add 2 - 3 parts by weight of the antibacterial modifier, cetyltrimethylammonium chloride, and fatty alcohol polyoxyethylene ether into deionized water to obtain a mixed liquid. Drop the mixture and the mixed liquid into the mixed solution, react, and prepare the modified acrylate emulsion; S3: Preparation of Modified Zinc Oxide First, adjust the pH of the 37 wt% zinc oxide slurry to 9 - 10, then heat up and add sodium silicate solution and coupling agent HMDS. After reaction, add sodium aluminate solution and continue to react. Finally, add hydroxy silicone oil to react and prepare modified zinc oxide; S4: Preparation of Composite Coating Mix 60 - 70 parts by weight of modified acrylate emulsion, 0.1 - 0.3 parts by weight of defoamer, 0.2 - 0.5 parts by weight of leveling agent, 3 - 5 parts by weight of curing agent, 0.5 - 1 part by weight of thickener, and pre - dispersed modified zinc oxide slurry and stir to prepare the composite coating.

[0008] Furthermore, the preparation of the antibacterial modifier in step S1 specifically includes the following steps: Add 10 - 12 parts by weight of dimethylaminoethyl methacrylate, 18.8 - 19.3 parts by weight of cetyl bromide, and 0.01 - 0.02 parts by weight of 2,6 - di - tert - butyl - p - cresol into 20 - 30 parts by weight of acetone. Stir and react at 300 - 500 r / min and 45 - 48 °C under magnetic stirring for 12 - 13 h. After the reaction is completed, cool to room temperature, then add 50 - 80 parts by weight of ether, then filter, wash, and dry to obtain the antibacterial modifier.

[0009] Furthermore, the preparation of the modified acrylate in step S2 specifically includes the following steps: S2.1: Add 3 - 5 parts by weight of azodiisobutyramidine hydrochloride into 15 - 23 parts by weight of deionized water, then stir and mix to obtain the azodiisobutyramidine hydrochloride solution; S2.2: Add 10 - 12 parts by weight of antibacterial modifier, 5 - 8 parts by weight of cetyltrimethylammonium chloride, and 3 - 5 parts by weight of fatty alcohol polyoxyethylene ether to 25 - 32 parts by weight of deionized water. After mechanical stirring and mixing, add 10 - 12 parts by weight of benzyl methacrylate and 10 - 12 parts by weight of n-butyl acrylate. Heat up to 75 - 80 °C, then add azodiisobutyramidine hydrochloride solution, and stir and react for 1 - 2 h to obtain a mixed solution; S2.3: Mix 5 - 8 parts by weight of benzyl methacrylate, 5 - 8 parts by weight of n-butyl acrylate, 1 - 2 parts by weight of 2-hydroxyethyl acrylate, and 1 - 2 parts by weight of glycidyl methacrylate to obtain a mixture. Add 5 - 8 parts by weight of antibacterial modifier, 3 - 5 parts by weight of cetyltrimethylammonium chloride, and 2 - 3 parts by weight of fatty alcohol polyoxyethylene ether to 15 - 20 parts by weight of deionized water to obtain a mixed liquid; S2.4: Drop the mixture and the mixed liquid into the mixed solution at 75 - 80 °C over 2 - 3 h. After the dropping is completed, react for 2 - 3 h, then cool to room temperature and filter to obtain a modified acrylate emulsion.

[0010] Further, the preparation of the modified zinc oxide in step S3 specifically includes the following steps: Add sodium hydroxide to 15 - 20 parts by weight of 37 wt% zinc oxide slurry to adjust the pH to 9 - 10. Heat up to 60 - 65 °C and stir and mix for 20 - 30 min. Then add 0.28 - 0.74 parts by weight of a 10 - 12% sodium silicate solution and 0.03 - 0.15 parts by weight of coupling agent HMDS. Then add sulfuric acid solution to adjust the pH to 9 - 10 and keep the temperature for reaction for 1 - 2 h. Then heat up to 80 - 83 °C and keep the temperature for reaction for 2 - 3 h. Then cool down to 60 - 63 °C, add 0.17 - 0.37 parts by weight of a 10 - 12% sodium aluminate solution, and at the same time add sulfuric acid solution to adjust the pH to 9 - 10 and react for 2 - 3 h. Then add 0.06 - 0.22 parts by weight of hydroxy silicone oil with a molecular weight of 5000, maintain the pH at 9 - 10 and react for 2 - 3 h. Then carry out suction filtration, washing, drying, and pulverization to obtain modified zinc oxide.

[0011] Further, the preparation of the composite coating in step S4 specifically includes the following steps: S4.1: Add 15 - 20 parts by weight of modified zinc oxide, 1 - 2 parts by weight of dispersant, and 10 - 13 parts by weight of deionized water to a high-speed dispersion kettle and disperse at a speed of 800 - 1200 rpm for 20 - 30 min to form a pre-dispersed modified zinc oxide slurry; S4.2: Add 60 - 70 parts by weight of the modified acrylate emulsion into the reaction kettle, with a stirring speed of 300 - 500 rpm. Then slowly add the pre-dispersed modified zinc oxide slurry, control the temperature at 25 - 30 °C, and sequentially add 0.1 - 0.3 parts by weight of defoamer, 0.2 - 0.5 parts by weight of leveling agent, 3 - 5 parts by weight of curing agent. Stir for 15 - 20 min, and finally add 0.5 - 1 part by weight of thickener. Stir for 1 - 2 h, screen, and let stand for 24 - 25 h to obtain the composite coating.

[0012] Further, in step S3, the hydroxy silicone oil is hydroxy silicone oil with a molecular weight of 5000.

[0013] Further, the dispersant in step S4.1 is hydroxypropyl methylcellulose.

[0014] Further, the curing agent in step S4.2 is triglycidyl cyanurate, the leveling agent is leveling agent BYK354, the thickener is glyceryl stearate, and the defoamer is BYK - 028.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The antibacterial modifier of the present invention is prepared by the quaternization reaction of dimethylaminoethyl methacrylate and cetyl bromide. The structure contains a long-chain alkyl quaternary ammonium salt group, and its positive charge can adsorb the negatively charged bacterial cell membrane, destroying the membrane structure and causing bacteria to die. The antibacterial modifier modifies the acrylate. In emulsion polymerization, the antibacterial modifier participates in copolymerization as a functional monomer and is bonded to the acrylate main chain through copolymerization to form a stable and persistent antibacterial effect. Adding the antibacterial modifier twice ensures its uniform distribution in the polymer chain, avoiding local concentration deficiency or agglomeration, and enhancing the overall antibacterial effect of the modified acrylate. Combined with the resin through covalent bonds, compared with physically mixed antibacterial agents, the antibacterial effect is more persistent, and at the same time, it can also avoid the problem of decreased antibacterial performance caused by the easy loss of small molecule antibacterial agents.

[0016] 2. The present invention simultaneously performs inorganic modification and organic modification on zinc oxide, which plays a role in controlling the particle size and also introduces organic substances, providing a basis for subsequent organic modification. As a silane coupling agent, HMDS can be adsorbed on the surface of zinc oxide, reducing its surface energy and the tendency of particle agglomeration; the introduced HMDS changes the surface polarity of zinc oxide, making zinc oxide easily adsorb hydroxy silicone oil, and the hydroxy silicone oil further coats the zinc oxide particles, forming a steric hindrance effect. The two work together to make zinc oxide more uniformly dispersed in the acrylic resin, avoiding performance non-uniformity caused by agglomeration, and enhancing the overall stability and consistency of the material.

[0017] 3. The present invention adds modified zinc oxide to the composite coating. After being coated and modified with the coupling agent HMDS and silicate, the surface active sites of zinc oxide increase, which can produce a synergistic effect with the antibacterial modifier. The slow release of Zn²⁺ from zinc oxide nanoparticles and the contact sterilization of the organic antibacterial agent form a dual mechanism, effectively improving the antibacterial effect of the coating. After curing, the epoxy group of the curing agent can react with the hydroxyl group of the modified acrylate and also react with the hydroxyl group on the surface of zinc oxide (hydroxyl silicone / silicon hydroxyl group), forming a covalent bond connection of "polymer - curing agent - zinc oxide", anchoring the filler particles in the coating network. In this process, zinc oxide is fixed through chemical covalent bonds rather than physical adsorption, significantly enhancing the binding force between the filler and the matrix, reducing agglomeration and shedding, and improving the durability of the antibacterial effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings incorporated herein and constituting a part of the specification illustrate embodiments of the present invention and, together with the specification, are further used to explain the principles of the present invention and enable those skilled in the relevant art to implement and use the present invention.

[0019] Figure 1 It is the structural reaction formula of the antibacterial modifier of the present invention.

[0020] Figure 2 It is the infrared spectrum of the antibacterial modifier of the present invention.

[0021] Figure 3 It is the surface microtopography of the modified zinc oxide of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following describes in detail an antibacterial acrylic resin composite coating and its preparation process provided by the present invention in conjunction with the drawings and specific embodiments. At the same time, it should be noted here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments. For some well-known technologies, those skilled in the art can also adopt other alternative methods for implementation; moreover, the drawing part is only for more specifically describing the embodiments and is not intended to specifically limit the present invention.

[0023] Example 1 A preparation process of an antibacterial acrylic resin composite coating includes the following steps: S1: Preparation of the antibacterial modifier Add 10 parts by weight of dimethylaminoethyl methacrylate, 18.8 parts by weight of cetyl bromide, and 0.01 part by weight of 2,6 - di - tert - butyl - p - cresol to 20 parts by weight of acetone, stir and react at 300 r / min and 45 °C under magnetic stirring for 12 h. After the reaction is completed, cool to room temperature, then add 50 parts by weight of ether, and then filter, wash, and dry to obtain the antibacterial modifier; S2: Preparation of the modified acrylate S2.1: Add 3 parts by weight of azobisisobutyramidine hydrochloride to 15 parts by weight of deionized water, and then stir and mix to obtain an azobisisobutyramidine hydrochloride solution; S2.2: Add 10 parts by weight of antibacterial modifier, 5 parts by weight of cetyltrimethylammonium chloride, and 3 parts by weight of fatty alcohol polyoxyethylene ether to 25 parts by weight of deionized water. After mechanical stirring and mixing, add 10 parts by weight of benzyl methacrylate and 10 parts by weight of n-butyl acrylate, heat up to 75 °C, and then add the azobisisobutyramidine hydrochloride solution, stir and react for 1 h to obtain a mixed solution; S2.3: Mix 5 parts by weight of benzyl methacrylate, 5 parts by weight of n-butyl acrylate, 1 part by weight of 2-hydroxyethyl acrylate, and 1 part by weight of glycidyl methacrylate to obtain a mixture. Add 5 parts by weight of antibacterial modifier, 3 parts by weight of cetyltrimethylammonium chloride, and 2 parts by weight of fatty alcohol polyoxyethylene ether to 15 parts by weight of deionized water to obtain a mixed liquid; S2.4: Drop the mixture and the mixed liquid into the mixed solution at 75 °C, the dropping time is 2 h. After the dropping is completed, react for 2 h, then cool to room temperature, filter to obtain a modified acrylate emulsion; S3: Preparation of modified zinc oxide Add sodium hydroxide to -20 parts by weight of 37 wt% zinc oxide slurry, adjust the pH to 9, heat up to 60 °C, stir and mix for 20 min, then add 0.28 parts by weight of 10% sodium silicate solution and 0.03 parts by weight of coupling agent HMDS. Then add sulfuric acid solution to adjust the pH to 9, keep warm and react for -2 h, then heat up to 80 °C, keep warm and react for 2 h, then cool down to 60 °C, add 0.17 parts by weight of 10% sodium metaaluminate solution, and at the same time add sulfuric acid solution to adjust the pH to 9, react for 2 h, then add 0.06 parts by weight of hydroxy silicone oil with a molecular weight of 5000, maintain the pH at 9, react for 2 h, then carry out suction filtration, washing, drying, and pulverization to obtain modified zinc oxide; S4: Preparation of composite coating S4.1: Add 15 parts by weight of modified zinc oxide, 1 part by weight of hydroxypropyl methylcellulose, and 10 parts by weight of deionized water to a high-speed dispersion kettle, disperse at a speed of 800 rpm for 20 min to form a pre-dispersed modified zinc oxide slurry; S4.2: Add 60 parts by weight of modified acrylate emulsion to a reaction kettle, stir at a speed of 300 rpm, then slowly add the pre-dispersed modified zinc oxide slurry, control the temperature at 25 °C, sequentially add 0.1 part by weight of defoamer BYK-028, 0.2 part by weight of leveling agent BYK354, 3 parts by weight of triglycidyl isocyanurate, stir for 15 min, and finally add 0.5 part by weight of glyceryl stearate, stir for 1 h, sieve, and let stand for 24 h to obtain a composite coating.

[0024] Example 2 A preparation process of an antibacterial acrylic resin composite coating comprises the following steps: S1: Preparation of an antibacterial modifier Add 10 parts by weight of dimethylaminoethyl methacrylate, 18.8 parts by weight of cetyl bromide, and 0.01 part by weight of 2,6 - di - tert - butyl - p - cresol to 20 parts by weight of acetone, stir and react at 500 r / min and 48 °C under magnetic stirring for 13 h. After the reaction is completed, cool to room temperature, then add 50 parts by weight of ether, and then filter, wash, and dry to obtain the antibacterial modifier; S2: Preparation of a modified acrylate S2.1: Add 3 parts by weight of azodiisobutyramidine hydrochloride to 15 parts by weight of deionized water, and then stir and mix to obtain an azodiisobutyramidine hydrochloride solution; S2.2: Add 10 parts by weight of the antibacterial modifier, 5 parts by weight of cetyltrimethylammonium chloride, and 3 parts by weight of fatty alcohol polyoxyethylene ether to 25 parts by weight of deionized water. After mechanical stirring and mixing, add 10 parts by weight of benzyl methacrylate and 10 parts by weight of n - butyl acrylate, heat up to 80 °C, and then add the azodiisobutyramidine hydrochloride solution, stir and react for 2 h to obtain a mixed solution; S2.3: Mix 5 parts by weight of benzyl methacrylate, 5 parts by weight of n - butyl acrylate, 1 part by weight of 2 - hydroxyethyl acrylate, and 1 part by weight of glycidyl methacrylate to obtain a mixture. Add 5 parts by weight of the antibacterial modifier, 3 parts by weight of cetyltrimethylammonium chloride, and 2 parts by weight of fatty alcohol polyoxyethylene ether to 15 parts by weight of deionized water to obtain a mixed liquid; S2.4: Drop the mixture and the mixed liquid into the mixed solution at 80 °C, the dropping time is 3 h. After the dropping is completed, react for 3 h, then cool to room temperature, filter to obtain a modified acrylate emulsion; S3: Preparation of modified zinc oxide Add sodium hydroxide to 15 parts by weight of 37 wt% zinc oxide slurry to adjust the pH to 9, heat up to 65 °C, stir and mix for 30 min, then add 0.28 part by weight of a 10% sodium silicate solution and 0.03 part by weight of coupling agent HMDS. Then add sulfuric acid solution to adjust the pH to 9, keep the temperature for reaction for 2 h, then heat up to 83 °C, keep the temperature for reaction for 3 h, then cool down to 63 °C, add 0.17 part by weight of a 10% sodium aluminate solution, and at the same time add sulfuric acid solution to adjust the pH to 9, react for 3 h. Then add 0.06 part by weight of hydroxy silicone oil with a molecular weight of 5000, maintain the pH at 9, react for 3 h, and then carry out suction filtration, washing, drying, and pulverization to obtain modified zinc oxide; S4: Preparation of the composite coating S4.1: Add 15 parts by weight of modified zinc oxide, 1 part by weight of hydroxypropyl methylcellulose, and 10 parts by weight of deionized water to a high-speed dispersion kettle, disperse at a speed of 1200 rpm for 30 min to form a pre-dispersed modified zinc oxide slurry; S4.2: Add 60 parts by weight of modified acrylate emulsion to a reaction kettle, stir at a speed of 500 rpm, then slowly add the pre-dispersed modified zinc oxide slurry, control the temperature at 30 °C, sequentially add 0.1 part by weight of defoamer BYK-028, 0.2 part by weight of leveling agent BYK354, 3 parts by weight of triglycidyl isocyanurate, stir for 20 min, finally add 0.5 part by weight of glyceryl stearate, stir for 2 h, screen, and let stand for 25 h to obtain a composite coating.

[0025] Example 3 A preparation process of an antibacterial acrylic resin composite coating includes the following steps: S1: Preparation of antibacterial modifier Add 12 parts by weight of dimethylaminoethyl methacrylate, 19.3 parts by weight of cetyl bromide, and 0.02 part by weight of 2,6-di-tert-butyl-p-cresol to 30 parts by weight of acetone, stir and react at 300 r / min and 45 °C under magnetic stirring for 12 h. After the reaction is completed, cool to room temperature, then add 80 parts by weight of ether, and then filter, wash, and dry to obtain an antibacterial modifier; S2: Preparation of modified acrylate S2.1: Add 5 parts by weight of azodiisobutyramidine hydrochloride to 23 parts by weight of deionized water, and then stir and mix to obtain an azodiisobutyramidine hydrochloride solution; S2.2: Add 12 parts by weight of antibacterial modifier, 8 parts by weight of cetyltrimethylammonium chloride, and 5 parts by weight of fatty alcohol polyoxyethylene ether to 32 parts by weight of deionized water, mechanically stir and mix, then add 12 parts by weight of benzyl methacrylate and 12 parts by weight of n-butyl acrylate, heat up to 75 °C, and then add the azodiisobutyramidine hydrochloride solution, stir and react for 1 h to obtain a mixed solution; S2.3: Mix 8 parts by weight of benzyl methacrylate, 8 parts by weight of n-butyl acrylate, 2 parts by weight of 2-hydroxyethyl acrylate, and 2 parts by weight of glycidyl methacrylate to obtain a mixture. Add 8 parts by weight of antibacterial modifier, 5 parts by weight of cetyltrimethylammonium chloride, and 3 parts by weight of fatty alcohol polyoxyethylene ether to 20 parts by weight of deionized water to obtain a mixed liquid; S2.4: Drop the mixture and the mixed liquid into the mixed solution at 75 °C within 2 h. After the dropping is completed, react for 2 h, then cool to room temperature, and filter to obtain a modified acrylate emulsion; S3: Preparation of modified zinc oxide Sodium hydroxide was added to 20 parts by weight of 37 wt% zinc oxide slurry, the pH was adjusted to 10, the temperature was raised to 60 °C, and the mixture was stirred for 20 min. Then, 0.74 parts by weight of 12% sodium silicate solution and 0.15 parts by weight of coupling agent HMDS were added. After that, sulfuric acid solution was added to adjust the pH to 10, and the reaction was carried out at a constant temperature for 1 h. Then, the temperature was raised to 80 °C and the reaction was carried out at a constant temperature for 2 h. Then, the temperature was lowered to 60 °C, 0.37 parts by weight of 12% sodium aluminate solution was added, and at the same time, sulfuric acid solution was added to adjust the pH to 10, and the reaction was carried out for 2 h. Then, 0.22 parts by weight of hydroxy silicone oil with a molecular weight of 5000 was added, the pH was maintained at 10, and the reaction was carried out for 2 h. Then, filtration, washing, drying, and pulverization were carried out to obtain modified zinc oxide; S4: Preparation of composite coating S4.1: 20 parts by weight of modified zinc oxide, 2 parts by weight of hydroxypropyl methylcellulose, and 13 parts by weight of deionized water were added to a high-speed dispersion kettle and dispersed at a speed of 800 rpm for 20 min to form a pre-dispersed modified zinc oxide slurry; S4.2: 70 parts by weight of modified acrylate emulsion was added to a reaction kettle, the stirring speed was 300 rpm, and then the pre-dispersed modified zinc oxide slurry was slowly added, and the temperature was controlled at 25 °C. 0.3 parts by weight of defoamer BYK-028, 0.5 parts by weight of leveling agent BYK354, and 5 parts by weight of triglycidyl isocyanurate were added in sequence, and the mixture was stirred for 15 min. Finally, 1 part by weight of glyceryl stearate was added, and the mixture was stirred for 1 h, sieved, and allowed to stand for 24 h to obtain a composite coating.

[0026] Comparative example 1 Compared with Example 1, the difference in Comparative Example 1 was that the antibacterial modifiers in Steps S1, S2.2, and S2.3 were removed, and the composite coating was prepared with the remaining steps unchanged, denoted as Comparative Example 1.

[0027] Comparative example 2 Compared with Example 1, the difference in Comparative Example 2 was that Step S3 was removed, and the modified zinc oxide in Step S4.1 was replaced with an equal mass of zinc oxide, and the composite coating was prepared with the remaining steps unchanged, denoted as Comparative Example 2.

[0028] Comparative example 3 Compared with Example 1, the difference in Comparative Example 3 was that the hydroxy silicone oil in Step S3 was removed, and the composite coating was prepared with the remaining steps unchanged, denoted as Comparative Example 3.

[0029] Comparative example 4 Compared with Example 1, the difference in Comparative Example 4 was that the coupling agent HMDS in Step S3 was removed, and the composite coating was prepared with the remaining steps unchanged, denoted as Comparative Example 4.

[0030] Comparative example 5 Compared with Example 1, the difference in Comparative Example 5 is that in Comparative Example 5, the antibacterial modifier in Steps S2.2 and S2.3 is removed, and the antibacterial modifier is added to S4.2 in an equal weight part as the antibacterial agent, and the remaining steps remain unchanged to prepare the composite coating, denoted as Comparative Example 5.

[0031] The composite coatings obtained in Examples 1 - 3 and Comparative Examples 1 - 5 were sprayed on standard test panels pretreated in accordance with the "Standard Test Panels for Paints and Varnishes" of GB / T9271 - 2008, and cured at 150 °C for 30 min to prepare test samples. The test samples of Examples 1 - 3 and Comparative Examples 1 - 5 were tested for antibacterial properties against Escherichia coli and Staphylococcus aureus, and the test results are shown in Table 1 for reference.

[0032] Table 1. Antibacterial Rate Determination Results of Examples 1 - 3 and Comparative Examples 1 - 4

[0033] It can be seen from the data in Table 1 that modifying acrylate with the antibacterial modifier can effectively improve the antibacterial effect of the coating, and using HMDS and hydroxy silicone oil to synergistically wrap - modify zinc oxide can produce a synergistic effect with the antibacterial modifier to improve the antibacterial effect.

[0034] The test samples of Examples 1 - 3 and Comparative Examples 2 - 5 were placed outdoors for 30 d and then retested for the antibacterial rates against Escherichia coli and Staphylococcus aureus, and the test results are shown in Table 2 for reference.

[0035] Table 1. Antibacterial Rate Determination Results of Examples 1 - 3 and Comparative Examples 1 - 4

[0036] It can be seen from the data of Comparative Example 5 in Table 2 that compared with the physically mixed antibacterial agent, the antibacterial effect is more persistent when the antibacterial modifier participates in copolymerization as a functional monomer. It can be seen from Comparative Examples 2 - 4 that adding the zinc oxide with modified coating can significantly improve the long - term antibacterial property.

[0037] Figures 1-2 It can be seen that the antibacterial modifier was successfully synthesized. Figure 3 It can be seen the modified coating structure of the modified zinc oxide, and it has good dispersibility.

[0038] The above - mentioned examples are only illustrative of the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above - mentioned examples without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. An antibacterial acrylic resin composite coating, characterized in that, The composite coating comprises the following components: 60 - 70 parts by weight of modified acrylate emulsion, 0.1 - 0.3 parts by weight of defoamer, 0.2 - 0.5 parts by weight of leveling agent, 3 - 5 parts by weight of curing agent, 0.5 - 1 part by weight of thickener and pre-dispersed modified zinc oxide slurry; The pre-dispersed modified zinc oxide slurry comprises 15 - 20 parts by weight of modified zinc oxide, 1 - 2 parts by weight of dispersant and 10 - 13 parts by weight of deionized water; The modified acrylate emulsion is copolymerized from an antibacterial modifier, azodiisobutyramidine hydrochloride, cetyltrimethylammonium chloride, fatty alcohol polyoxyethylene ether, benzyl methacrylate, n-butyl acrylate, 2-hydroxyethyl acrylate and glycidyl methacrylate; The antibacterial modifier is obtained by reacting dimethylaminoethyl methacrylate, hexadecyl bromide and 2,6-di-tert-butyl-p-cresol; The modified zinc oxide is obtained by synergistic modification of coupling agent HMDS and hydroxy silicone oil.

2. The preparation process of an antibacterial acrylic resin composite coating according to claim 1, characterized in that, It includes the following steps: S1: Preparation of antibacterial modifier Add 10 - 12 parts by weight of dimethylaminoethyl methacrylate, 18.8 - 19.3 parts by weight of hexadecyl bromide and 0.01 - 0.02 parts by weight of 2,6-di-tert-butyl-p-cresol into 20 - 30 parts by weight of acetone. After reaction, add ether, then filter, wash and dry to obtain the antibacterial modifier; S2: Preparation of modified acrylate Add the antibacterial modifier, cetyltrimethylammonium chloride and fatty alcohol polyoxyethylene ether into deionized water, then add benzyl methacrylate, n-butyl acrylate and azodiisobutyramidine hydrochloride solution to obtain a mixed solution. Mix benzyl methacrylate, n-butyl acrylate, 2-hydroxyethyl acrylate and glycidyl methacrylate to obtain a mixture. Add 2 - 3 parts by weight of the antibacterial modifier, cetyltrimethylammonium chloride and fatty alcohol polyoxyethylene ether into deionized water to obtain a mixed liquid. Drop the mixture and the mixed liquid into the mixed solution, react to prepare the modified acrylate emulsion; S3: Preparation of modified zinc oxide First, adjust the pH of 37wt% zinc oxide slurry to 9 - 10, then heat up and add sodium silicate solution, coupling agent HMDS. After reaction, add sodium aluminate solution and continue to react. Finally, add hydroxy silicone oil and react to prepare modified zinc oxide; S4: Preparation of composite coating Mix 60 - 70 parts by weight of modified acrylate emulsion, 0.1 - 0.3 parts by weight of defoamer, 0.2 - 0.5 parts by weight of leveling agent, 3 - 5 parts by weight of curing agent, 0.5 - 1 part by weight of thickener and pre-dispersed modified zinc oxide slurry and stir to prepare the composite coating.

3. The preparation process of an antibacterial acrylic resin composite coating according to claim 2, characterized in that, The preparation of the antibacterial modifier in step S1 specifically includes the following steps: Add 10 - 12 parts by weight of dimethylaminoethyl methacrylate, 18.8 - 19.3 parts by weight of hexadecyl bromide and 0.01 - 0.02 parts by weight of 2,6-di-tert-butyl-p-cresol into 20 - 30 parts by weight of acetone. Stir and react at 300 - 500 r / min and 45 - 48 °C under magnetic stirring for 12 - 13 h. After the reaction is completed, cool to room temperature, then add 50 - 80 parts by weight of ether, then filter, wash and dry to obtain the antibacterial modifier.

4. The preparation process of an antibacterial acrylic resin composite coating according to claim 2, characterized in that, Step S2 Preparation of modified acrylate, which specifically includes the following steps: S2.1: Add 3-5 parts by weight of azodiisobutyramidine hydrochloride to 15-23 parts by weight of deionized water, and then stir and mix to obtain an azodiisobutyramidine hydrochloride solution; S2.2: Add 10-12 parts by weight of antibacterial modifier, 5-8 parts by weight of cetyltrimethylammonium chloride, and 3-5 parts by weight of fatty alcohol polyoxyethylene ether to 25-32 parts by weight of deionized water. After mechanical stirring and mixing, add 10-12 parts by weight of benzyl methacrylate and 10-12 parts by weight of n-butyl acrylate, heat up to 75-80 °C, and then add the azodiisobutyramidine hydrochloride solution, stir and react for 1-2 h to obtain a mixed solution; S2.3: Mix 5-8 parts by weight of benzyl methacrylate, 5-8 parts by weight of n-butyl acrylate, 1-2 parts by weight of 2-hydroxyethyl acrylate, and 1-2 parts by weight of glycidyl methacrylate to obtain a mixture. Add 5-8 parts by weight of antibacterial modifier, 3-5 parts by weight of cetyltrimethylammonium chloride, and 2-3 parts by weight of fatty alcohol polyoxyethylene ether to 15-20 parts by weight of deionized water to obtain a mixed liquid; S2.4: Drop the mixture and the mixed liquid into the mixed solution at 75-80 °C, the dropping time is 2-3 h. After the dropping is completed, react for 2-3 h, then cool to room temperature, filter to obtain a modified acrylate emulsion.

5. The preparation process of an antibacterial acrylic resin composite coating according to claim 2, characterized in that, Step S3 Preparation of modified zinc oxide, which specifically includes the following steps: Add sodium hydroxide to 15-20 parts by weight of 37 wt% zinc oxide slurry, adjust the pH to 9-10, heat up to 60-65 °C, stir and mix for 20-30 min, then add 0.28-0.74 parts by weight of a 10-12% sodium silicate solution and 0.03-0.15 parts by weight of coupling agent HMDS. Then add sulfuric acid solution to adjust the pH to 9-10, keep the temperature and react for 1-2 h. Then heat up to 80-83 °C, keep the temperature and react for 2-3 h. Then cool down to 60-63 °C, add 0.17-0.37 parts by weight of a 10-12% sodium aluminate solution, and at the same time add sulfuric acid solution to adjust the pH to 9-10, react for 2-3 h. Then add 0.06-0.22 parts by weight of hydroxy silicone oil with a molecular weight of 5000, maintain the pH at 9-10, react for 2-3 h. Then carry out suction filtration, washing, drying, and pulverization to obtain modified zinc oxide.

6. The preparation process of an antibacterial acrylic resin composite coating according to claim 2, characterized in that, Step S4 Preparation of composite coating, which specifically includes the following steps: S4.1: Add 15-20 parts by weight of modified zinc oxide, 1-2 parts by weight of dispersant, and 10-13 parts by weight of deionized water to a high-speed dispersion kettle, disperse at a speed of 800-1200 rpm for 20-30 min to form a pre-dispersed modified zinc oxide slurry; S4.2: Add 60 - 70 parts by weight of the modified acrylate emulsion into a reaction kettle, with a stirring speed of 300 - 500 rpm. Then slowly add the pre-dispersed modified zinc oxide slurry, control the temperature at 25 - 30 °C, and sequentially add 0.1 - 0.3 parts by weight of defoamer, 0.2 - 0.5 parts by weight of leveling agent, and 3 - 5 parts by weight of curing agent. Stir for 15 - 20 min. Finally, add 0.5 - 1 part by weight of thickener and stir for 1 - 2 h. Screen and let stand for 24 - 25 h to obtain the composite coating.

7. The preparation process of an antibacterial acrylic resin composite coating according to claim 5, characterized in that, In step S3, the hydroxy silicone oil is a hydroxy silicone oil with a molecular weight of 5000.

8. The preparation process of an antibacterial acrylic resin composite coating according to claim 6, characterized in that, The dispersant in step S4.1 is hydroxypropyl methylcellulose.

9. The preparation process of an antibacterial acrylic resin composite coating according to claim 6, characterized in that, The curing agent in step S4.2 is triglycidyl cyanurate, the leveling agent is leveling agent BYK354, the thickener is glyceryl stearate, and the defoamer is BYK-028.

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