Ultraviolet curing type modified acrylic resin coating and application thereof

Abstract

The invention belongs to the technical field of acrylic resin coatings, and particularly relates to an ultraviolet curing type modified acrylic resin coating and application thereof. The preparation method comprises the following steps: uniformly mixing and stirring modified acrylic resin, a diluent, an adhesion promoter, an antibacterial toughening filler, a photoinitiator and a flatting agent to prepare the ultraviolet curing type modified acrylic resin coating. A rosin group and a lactone monomer of the modified acrylic resin can improve the weather resistance and the impact resistance of the coating; the antibacterial toughening filler can be uniformly dispersed in the coating in the modified acrylic resin coating, so that the toughness and antibacterial property of the coating are improved; the ultraviolet curing type modified acrylic resin coating disclosed by the invention is applied to a metal protective coating, and has excellent adhesive force and long-acting antibacterial property.

Description

Technical Field

[0001] The invention belongs to the technical field of acrylic resin coatings, and in particular relates to an ultraviolet light-curing modified acrylic resin coating and an application thereof. Background Art

[0002] UV-curable coatings offer advantages such as fast curing speed, low-temperature curing capability, and zero volatile organic compound emissions. UV-curable coatings primarily consist of oligomers, photoinitiators, and reactive monomer diluents. Oligomers directly determine the properties of the coating, so they are added in relatively large quantities. Photoinitiators initiate polymerization reactions, providing active polymerization centers and directly influencing the formation and properties of the coating. Reactive monomer diluents are multifunctional components that not only dilute the coating, ensuring optimal coating properties, but also regulate the polymerization rate.

[0003] Chinese invention patent publication number CN114806388B discloses a UV-curable matte coating, its preparation method, and products. The UV-curable matte coating, based on the total mass of the UV-curable matte coating as 100%, comprises 30-50wt% of an easily matted acrylic resin, 10-30wt% of a multifunctional aliphatic polyurethane acrylate, 4-6wt% of a photoinitiator, 10-20wt% of a reactive monomer, and 6-10wt% of a matting powder. The easily matted acrylic resin is prepared by reacting an HDI trimer with diethoxylated hydroxyethyl acrylate. The resulting paint film combines a high matte effect with excellent abrasion resistance, high adhesion, and good boiling water resistance and alcohol resistance. However, the prior art lacks a technical problem in further improving the antibacterial properties and adhesion of the acrylic resin coating by combining and modifying the functional filler components with the acrylic resin monomers. Summary of the Invention

[0004] The purpose of the present invention is to provide a UV-curable modified acrylic resin coating and its application, which is used to solve the technical problem in the prior art that the antibacterial properties and adhesion of the acrylic resin coating cannot be further improved by combining and modifying the components of the functional filler and the monomer of the acrylic resin.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A UV-curable modified acrylic resin coating is prepared from the following components in parts by weight: 60~70 parts of modified acrylic resin, 2~5 parts of photoinitiator, 30~40 parts of diluent, 0.5~1.5 parts of antibacterial toughening filler, 1~3 parts of adhesion promoter and 0.5~2 parts of leveling agent.

[0006] Preferably, the photoinitiator is any one of photoinitiator 1173 and photoinitiator 819.

[0007] Preferably, the diluent is any one of sec-butyl acetate, ethyl acetate, and propylene glycol methyl ether acetate.

[0008] Preferably, the adhesion promoter is an acrylic acid phosphate ester promoter, and the model is any one of FM20 and KM2106.

[0009] Preferably, the leveling agent is any one of BYK-333 and BYK-331.

[0010] Preferably, the preparation method of the modified acrylic resin comprises the following steps: S11. Add 50-60 parts by mass of xylene into a reactor, add 5-10 parts of methyl acrylate, 15-20 parts of methyl methacrylate, 15-20 parts of hydroxy acrylate, 10-15 parts of isobornyl acrylate, 3-5 parts of lactone monomer, 5-8 parts of glycidyl methacrylate and 0.05-1 part of di-tert-butyl peroxide initiator, and heat to react to prepare an acrylic acid prepolymer; S12, adding 90-100 parts by mass of rosin pentaerythritol ester to a reactor, adding 10-15 parts of glycidyl methacrylate, 1-2 parts of p-methoxyphenol and 1-1.5 parts of triphenylphosphine, and reacting to obtain rosin-modified acrylate; S13. Add 50-60 parts by mass of acrylic prepolymer, 12-14 parts by mass of rosin-modified acrylate, and 0.05-1 part by mass of di-tert-butyl peroxide initiator into a reactor to react and obtain a modified acrylic resin.

[0011] Preferably, in S11, the temperature is raised to 130-180° C. and the reaction is carried out for 2-4 hours, and the lactone monomer is any one of acrylate caprolactone, 2-methylenylbutyrolactone, and 3-methacrylate-4-butyrolactone.

[0012] Preferably, the reaction mechanism in S11 is a free radical polymerization reaction. Methyl acrylate, methyl methacrylate, hydroxy acrylate, isobornyl acrylate, lactone monomer, and glycidyl methacrylate all contain double bonds. When the di-tert-butyl peroxide initiator is heated, it decomposes to form free radicals. The free radicals attack the double bonds, causing the double bonds to participate in the free radical polymerization reaction, and polymerize to form chain macromolecules containing hydroxyl groups, ester groups, lactone groups and epoxy groups, that is, acrylic prepolymers.

[0013] Preferably, the temperature in S12 is raised to 110-130° C. and the reaction is carried out for 2-4 hours.

[0014] Preferably, in S13, the temperature is raised to 130-180° C. and the reaction is carried out for 2-4 hours.

[0015] Preferably, the reaction mechanism in S13 is a free radical polymerization reaction, and the double bonds of the rosin-modified acrylate and the acrylic acid prepolymer are polymerized to introduce the rosin groups.

[0016] Preferably, the method for preparing the antibacterial toughening filler comprises the following steps: S21. Add 2 to 2.5 parts of zinc nitrate, 0.05 to 0.15 parts of magnesium nitrate, and 0.3 to 0.6 parts of ferrous nitrate to 40 to 50 parts of N,N-dimethylformamide, stir evenly, and then add 100 to 110 parts of 2-methylimidazole and 30 to 40 parts of 2-aminobenzimidazole to a mixed solution, stir to react, and cool to obtain a zeolite framework; S22. Add 0.4-0.6 parts of zeolite framework to 40-60 parts of dopamine hydrochloric acid solution by mass, react at 20-30° C. for 12-18 hours, collect the solid by dialysis to obtain an antibacterial additive, add 1-2 parts of the antibacterial additive to 40-50 parts of deionized water, add 0.3-0.5 parts of Tween-80, and stir to obtain an aqueous phase; S23. Dissolve 4-5 parts of isophorone diisocyanate trimer and 10-15 parts of dioctyl terephthalate in 30-50 parts of ethyl acetate, add 0.01-0.03 parts of dibutyltin dilaurate and 2-4 parts of polyethylene glycol, and carry out prepolymerization to obtain an oil phase. Mix the oil phase and the aqueous phase, stir at a high speed and heat to react, and then add 0.5-2 parts of ethylene glycol to react to obtain an antibacterial toughening filler.

[0017] Preferably, the molar ratio of zinc nitrate, magnesium nitrate and ferrous nitrate in S21 is 8:0.5~1:0.5~1.5. Zinc nitrate, magnesium nitrate and ferrous nitrate are added to N,N-dimethylformamide and stirred evenly, and then quickly added to the mixed solution. The mixture is stirred at room temperature for 4~6 hours, heated to 40~50°C and stirred for 1~2 hours, and then filtered to collect the solid after cooling and washed with anhydrous ethanol.

[0018] Preferably, the dopamine hydrochloric acid solution in S22 is prepared by adding 1.2-2 g of tris(hydroxymethyl)aminomethane to 40-50 mL of deionized water, adjusting the pH to 8.5 with hydrochloric acid and sodium hydroxide solution, and then adding 0.4-0.5 g of dopamine hydrochloride and mixing.

[0019] Preferably, in S23, the temperature is raised to 40-50° C. for prepolymerization reaction for 5-10 minutes, and the mixture is homogenized at a speed of 2500-3500 rpm for 5-10 minutes. The temperature is raised to 50-60° C. for reaction for 1-2 hours, and ethylene glycol is added and kept warm for reaction for 1-2 hours.

[0020] Preferably, the reaction mechanism in S23 is as follows: isophorone diisocyanate trimer acts as a cross-linking agent, reacts with polyethylene glycol and ethylene glycol to form polyurethane, the oil phase and the water phase form an emulsion during high-speed homogenization and stirring, the polyurethane forms particle capsules at the emulsion interface, and the capsules encapsulate the antibacterial additive to produce an antibacterial toughening filler.

[0021] An application of a UV-curable modified acrylic resin coating for preparing a metal protective coating comprises the following steps: S1, adding modified acrylic resin, diluent, adhesion promoter and antibacterial toughening filler into a stirring tank, adding photoinitiator and leveling agent, and stirring evenly to prepare UV-curable modified acrylic resin coating; S2. Applying resin coating on an aluminum plate and curing it with ultraviolet light to obtain a coating.

[0022] Preferably, the coating thickness in S2 is 100-200 μm, and is cured by ultraviolet light for 30-50 minutes.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention rationally selects multiple reactive monomers including methyl acrylate, methyl methacrylate, hydroxy acrylate, isobornyl acrylate, lactone monomer and glycidyl methacrylate to react to prepare an acrylic prepolymer, which is then reacted with rosin-modified acrylate to prepare a modified acrylic resin. The lactone monomer has flexibility and steric hindrance, thereby improving the flexibility and impact resistance of the modified acrylic resin. Rosin modification improves the aging resistance and hydrophobicity of the acrylic resin. Hydroxy acrylate and glycidyl methacrylate provide polar groups with hydroxyl and ester groups, which can synergistically act with an adhesion promoter to enhance chemical bonding with the aluminum plate, thereby improving adhesion and impact resistance. The step-by-step polymerization can avoid the problem of the rosin-modified acrylate being unable to effectively participate in crosslinking due to differences in reactivity ratios during direct copolymerization.

[0024] 2. The present invention uses zinc nitrate, magnesium nitrate and ferrous nitrate as raw materials, 2-aminobenzimidazole and 2-methylimidazole as ligands to prepare a zeolite framework, then uses dopamine to coat the zeolite framework to prepare an antibacterial additive, and finally uses polyurethane capsules to encapsulate it to prepare an antibacterial toughening filler; ferrous ions are doped into the zeolite framework to improve the antibacterial performance, 2-aminobenzimidazole is used as a ligand to partially replace 2-methylimidazole, amino active sites are introduced, which can react with hydroxyl groups, thereby improving the bonding strength between the zeolite framework and dopamine, and polyurethane capsules can be used to encapsulate the antibacterial additive evenly in the acrylic resin coating, and the polyurethane capsules can slowly release metal ions, prolong the antibacterial effect, and improve the service life of the acrylic resin coating.

[0025] 3. The present invention uniformly mixes and stirs a modified acrylic resin, a diluent, an adhesion promoter, an antibacterial toughening filler, a photoinitiator, and a leveling agent to prepare a UV-curable modified acrylic resin coating; the rosin group and lactone monomer of the modified acrylic resin can improve the weather resistance and impact resistance of the coating; the antibacterial toughening filler can be uniformly dispersed in the modified acrylic resin coating, thereby improving the toughness and antibacterial properties of the coating; the UV-curable modified acrylic resin coating of the present invention is applied to metal protective coatings and has excellent adhesion and long-lasting antibacterial properties. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] Example 1: A UV-curable modified acrylic resin coating of this embodiment is prepared from the following components: 65g modified acrylic resin, 2g photoinitiator, 30g diluent, 0.8g antibacterial toughening filler, 1g adhesion promoter and 0.5g leveling agent.

[0028] The photoinitiator is photoinitiator 1173; the diluent is sec-butyl acetate; the adhesion promoter is an acrylic acid phosphate promoter, model FM20; and the leveling agent model is BYK-333.

[0029] The preparation method of the modified acrylic resin of this embodiment comprises the following steps: S11, adding 50g of xylene to a reactor, adding 8g of methyl acrylate, 16g of methyl methacrylate, 20g of hydroxy acrylate, 13g of isobornyl acrylate, 4g of caprolactone acrylate, 8g of glycidyl methacrylate and 0.8g of di-tert-butyl peroxide initiator, raising the temperature to 140°C and reacting for 2h to obtain an acrylic acid prepolymer; S12, adding 90g of rosin pentaerythritol ester to a reactor, adding 10g of glycidyl methacrylate, 1g of p-methoxyphenol and 1g of triphenylphosphine, raising the temperature to 130°C and reacting for 2h to obtain rosin-modified acrylate; S13. Add 50 g of acrylic prepolymer, 12 g of rosin-modified acrylate and 0.5 g of di-tert-butyl peroxide initiator into a reactor according to mass parts, heat to 150° C. and react for 2 h to obtain a modified acrylic resin.

[0030] The preparation method of the antibacterial toughening filler of this embodiment includes the following steps: S21, 2g of zinc nitrate, 0.1g of magnesium nitrate and 0.36g of ferrous nitrate were added to 40g of N, N-dimethylformamide, and stirred evenly, and then quickly added to a mixed solution consisting of 100g of 2-methylimidazole and 30g of 2-aminobenzimidazole, and stirred at room temperature for 4h, heated to 50°C and stirred for 1h, and then filtered to collect the solid after cooling, washed with anhydrous ethanol, dried, and cooled to obtain a zeolite framework; S22, adding 1.2 g of tris (hydroxymethyl)aminomethane to 40 mL of deionized water, adjusting the pH to 8.5 with hydrochloric acid and sodium hydroxide solution, then adding 0.4 g of dopamine hydrochloride and mixing to prepare a dopamine hydrochloric acid solution, adding 0.4 g of zeolite framework to 40 g of the dopamine hydrochloric acid solution, reacting at 20 ° C for 18 h, dialyzing and collecting the solid to prepare an antibacterial auxiliary agent, adding 1 g of the antibacterial auxiliary agent to 40 g of deionized water, adding 0.3 g of Tween-80, and stirring to obtain an aqueous phase; S23. Dissolve 4 g of isophorone diisocyanate trimer and 10 g of dioctyl terephthalate in 30 g of ethyl acetate, add 0.01 g of dibutyltin dilaurate and 2.5 g of polyethylene glycol, raise the temperature to 50°C and carry out prepolymerization reaction for 10 minutes to obtain an oil phase, mix the oil phase and the aqueous phase, stir at a high speed of 2500 rpm for 5 minutes, raise the temperature to 60°C and react for 2 hours, add 1 g of ethylene glycol, keep the temperature and react for 2 hours to obtain an antibacterial toughening filler.

[0031] The UV-curable modified acrylic resin coating of this embodiment is used to prepare a metal protective coating, comprising the following steps: S1, adding modified acrylic resin, diluent, adhesion promoter and antibacterial toughening filler into a stirring tank, adding photoinitiator and leveling agent, and stirring evenly to prepare UV-curable modified acrylic resin coating; S2. Apply the resin coating on the aluminum plate with a coating thickness of 100 μm, and cure it with ultraviolet light for 30 minutes to obtain a coating.

[0032] Example 2: A UV-curable modified acrylic resin coating of this embodiment is prepared from the following components: 60g modified acrylic resin, 3g photoinitiator, 35g diluent, 0.5g antibacterial toughening filler, 2g adhesion promoter and 1g leveling agent.

[0033] The photoinitiator is photoinitiator 1173; the diluent is propylene glycol methyl ether acetate; the adhesion promoter is an acrylic acid phosphate promoter, model KM2106; and the leveling agent model is BYK-333.

[0034] The preparation method of the modified acrylic resin of this embodiment comprises the following steps: S11, adding 55g of xylene to a reactor, adding 5g of methyl acrylate, 20g of methyl methacrylate, 16g of hydroxy acrylate, 11g of isobornyl acrylate, 5g of 3-methacrylate-4-butyrolactone, 5g of glycidyl methacrylate and 0.1g of di-tert-butyl peroxide initiator, raising the temperature to 160°C and reacting for 2h to obtain an acrylic acid prepolymer; S12, adding 92g of rosin pentaerythritol ester to a reactor, adding 13g of glycidyl methacrylate, 1.5g of p-methoxyphenol and 1.3g of triphenylphosphine, heating to 130°C and reacting for 3h to obtain rosin-modified acrylate; S13. Add 55 g of acrylic prepolymer, 13 g of rosin-modified acrylate and 0.9 g of di-tert-butyl peroxide initiator into a reactor, heat to 180° C. and react for 2 h to obtain a modified acrylic resin.

[0035] The preparation method of the antibacterial toughening filler of this embodiment includes the following steps: S21, 2.5g of zinc nitrate, 0.12g of magnesium nitrate and 0.45g of ferrous nitrate were added to 40-50g of N, N-dimethylformamide, and stirred evenly, and then quickly added to a mixed solution of 105g of 2-methylimidazole and 35g of 2-aminobenzimidazole, and stirred at room temperature for 4h, heated to 45°C and stirred for 1.5h, and after cooling, the solid was collected by filtration, washed with anhydrous ethanol, dried, and cooled to obtain a zeolite framework; S22, adding 1.5 g of tris (hydroxymethyl)aminomethane to 50 mL of deionized water, adjusting the pH to 8.5 with hydrochloric acid and sodium hydroxide solution, then adding 0.5 g of dopamine hydrochloride and mixing to prepare a dopamine hydrochloric acid solution, adding 0.4 g of zeolite framework to 50 g of the dopamine hydrochloric acid solution, reacting at 30 ° C for 12 h, dialyzing and collecting the solid to prepare an antibacterial additive, adding 1.5 g of the antibacterial additive to 45 g of deionized water, adding 0.4 g of Tween-80, and stirring to obtain an aqueous phase; S23. Dissolve 4.5 g of isophorone diisocyanate trimer and 12 g of dioctyl terephthalate in 50 g of ethyl acetate, add 0.02 g of dibutyltin dilaurate and 3 g of polyethylene glycol, heat to 45 ° C and pre-polymerize for 10 minutes to obtain an oil phase, mix the oil phase and the aqueous phase, stir at a high speed of 3000 rpm for 7 minutes, heat to 55 ° C and react for 1.5 hours, add 0.5 g of ethylene glycol, keep warm and react for 1.5 hours to obtain an antibacterial toughening filler.

[0036] The UV-curable modified acrylic resin coating of this embodiment is used to prepare a metal protective coating, comprising the following steps: S1, adding modified acrylic resin, diluent, adhesion promoter and antibacterial toughening filler into a stirring tank, adding photoinitiator and leveling agent, and stirring evenly to prepare UV-curable modified acrylic resin coating; S2. Apply the resin coating on the aluminum plate with a coating thickness of 130 μm, and cure it with ultraviolet light for 35 minutes to obtain a coating.

[0037] Example 3: A UV-curable modified acrylic resin coating of this embodiment is prepared from the following components: 70g modified acrylic resin, 5g photoinitiator, 40g diluent, 1.3g antibacterial toughening filler, 3g adhesion promoter and 2g leveling agent.

[0038] The photoinitiator is photoinitiator 819; the diluent is ethyl acetate; the adhesion promoter is an acrylic acid phosphate promoter, model KM2106; and the leveling agent is model BYK-331.

[0039] The preparation method of the modified acrylic resin of this embodiment comprises the following steps: S11, adding 60g of xylene to a reactor, adding 10g of methyl acrylate, 18g of methyl methacrylate, 19g of hydroxy acrylate, 15g of isobornyl acrylate, 5g of 2-methylenylbutyrolactone, 8g of glycidyl methacrylate and 1g of di-tert-butyl peroxide initiator, raising the temperature to 150°C and reacting for 4h to obtain an acrylic acid prepolymer; S12, adding 100 g of rosin pentaerythritol ester to a reactor, adding 15 g of glycidyl methacrylate, 2 g of p-methoxyphenol and 1.5 g of triphenylphosphine, raising the temperature to 110° C. and reacting for 4 h to obtain rosin-modified acrylate; S13. Add 60 g of acrylic acid prepolymer, 14 g of rosin-modified acrylate and 1 g of di-tert-butyl peroxide initiator into a reactor, heat to 160° C. and react for 2 h to obtain a modified acrylic resin.

[0040] The preparation method of the antibacterial toughening filler of this embodiment includes the following steps: S21, 2g of zinc nitrate, 0.15g of magnesium nitrate and 0.3g of ferrous nitrate were added to 50g of N, N-dimethylformamide, and stirred evenly, and then quickly added to a mixed solution of 110g of 2-methylimidazole and 40g of 2-aminobenzimidazole, and stirred at room temperature for 6h, heated to 50°C and stirred for 2h, and then filtered to collect the solid after cooling, washed with anhydrous ethanol, dried, and cooled to obtain a zeolite framework; S22, adding 2 g of tris (hydroxymethyl)aminomethane to 50 mL of deionized water, adjusting the pH to 8.5 with hydrochloric acid and sodium hydroxide solution, then adding 0.5 g of dopamine hydrochloride and mixing to prepare a dopamine hydrochloric acid solution, adding 0.6 g of zeolite framework to 60 g of the dopamine hydrochloric acid solution, reacting at 30 ° C for 12 h, dialyzing and collecting the solid to prepare an antibacterial additive, adding 2 g of the antibacterial additive to 50 g of deionized water, adding 0.5 parts of Tween-80, and stirring to prepare an aqueous phase; S23. Dissolve 5 g of isophorone diisocyanate trimer and 15 g of dioctyl terephthalate in 50 g of ethyl acetate, add 0.03 g of dibutyltin dilaurate and 4 g of polyethylene glycol, raise the temperature to 50°C and carry out pre-polymerization reaction for 5 minutes to obtain an oil phase, mix the oil phase and the aqueous phase, stir at a high speed of 3500 rpm for 5 minutes, raise the temperature to 60°C and react for 2 hours, add 2 g of ethylene glycol, keep the temperature and react for 2 hours to obtain an antibacterial toughening filler.

[0041] The UV-curable modified acrylic resin coating of this embodiment is used to prepare a metal protective coating, comprising the following steps: S1, adding modified acrylic resin, diluent, adhesion promoter and antibacterial toughening filler into a stirring tank, adding photoinitiator and leveling agent, and stirring evenly to prepare UV-curable modified acrylic resin coating; S2. Apply the resin coating on the aluminum plate with a coating thickness of 200 μm, and cure it with ultraviolet light for 50 minutes to obtain a coating.

[0042] Comparative Example 1: The difference between this comparative example and Example 1 is that the modified acrylic resin does not contain rosin-modified acrylate.

[0043] Comparative Example 2: The difference between this comparative example and Example 1 is that the modified acrylic resin in this comparative example is prepared by polymerizing 5-10 g of methyl acrylate, 15-20 g of methyl methacrylate, 15-20 g of hydroxy acrylate, and 5-8 g of glycidyl methacrylate.

[0044] Comparative Example 3: This comparative example differs from Example 1 in that the antibacterial additive in the antibacterial toughening filler is replaced by zinc oxide.

[0045] Comparative Example 4: This comparative example differs from Example 1 in that the antibacterial toughening filler is replaced by an antibacterial adjuvant.

[0046] Performance Testing The viscosity of the modified acrylic resin coatings prepared in the examples and comparative examples was tested according to GB / T 1723-1993 "Determination of Coating Viscosity".

[0047] The solid content of the modified acrylic resin coatings prepared in each embodiment and comparative example was tested according to GB / T 1725-2007 “Paints, varnishes and plastics - Determination of non-volatile matter content”.

[0048] The modified acrylic resin coatings prepared in each example and comparative example were stirred at a rotation speed of 3000 rpm for 15 minutes, and the stability was measured by visually inspecting the delamination.

[0049] The adhesion grade of the coatings prepared in each embodiment and comparative example was tested according to GB / T 9286-2021 “Paint and varnish cross-cut test”.

[0050] The pencil hardness of the coatings prepared in the examples and comparative examples was tested according to GB / T 6739-2006 “Paints and varnishes - Determination of film hardness by pencil method”, using a Zhonghua brand pencil.

[0051] The impact strength of the coatings prepared in each embodiment and comparative example was tested according to GB / T 1732-2020 “Determination of impact resistance of paint films”.

[0052] The test results are shown in Table 1 below:

[0053] Antibacterial testing According to GB / T 21866-2008 “Determination of antimicrobial activity and antimicrobial efficacy of antimicrobial coatings (paint films)”, Escherichia coli was inoculated into plate count agar medium and cultured at 37°C for 24 hours. The culture was diluted with phosphate buffer solution to a concentration of 5.0 CFU / mL to prepare a bacterial solution.

[0054] An aluminum plate without acrylic coating was used as a control group. The aluminum plate coatings prepared in each embodiment and comparative example and the control group were wiped with ethanol and then placed under an ultraviolet lamp for sterilization for 30 minutes. After being laid flat, the bacterial solution was evenly applied. The aluminum plate coatings and the control group with the bacterial solution were placed in a sterile incubator with a humidity of 90% at 37°C for 24 hours. The number of colonies was recorded, and the antibacterial rate was calculated according to the following formula:

[0055] R is the antibacterial rate; R C is the colony count of the control group, in CFU / g; R B is the colony count of the aluminum plate coating, in CFU / g.

[0056] The test results are shown in Table 2 below:

[0057] From the above experimental data, it can be seen that the viscosity of the resin coatings prepared in Examples 1 to 3 is between 281 and 286 mPa·s, the solid content is between 64.39 and 68.14%, and they are all dispersed and stable when rotated at a speed of 3000 rpm for 15 minutes, indicating that the UV-curable modified acrylic resin coatings prepared in the present invention meet the basic requirements of the coatings, the adhesion grade is 0, and the impact strength is 50 kg·cm, indicating that the UV-curable modified acrylic resin coatings prepared in the present invention have excellent adhesion and impact resistance. The modified Example 2 The acrylic resin is prepared by polymerizing 5-10 g of methyl acrylate, 15-20 g of methyl methacrylate, 15-20 g of hydroxy acrylate, and 5-8 g of glycidyl methacrylate. Modification without adding a lactone monomer or modified acrylic resin results in decreased hardness and impact resistance, resulting in a pencil hardness of only 2H and an impact strength of only 30 kg·cm. The antibacterial rates of the resin coatings prepared in Examples 1-3 are between 97.0% and 98.1%, indicating that the UV-curable modified acrylic resin coatings prepared in the present invention have excellent antibacterial properties.

[0058] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

[0059] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A UV-curable modified acrylic resin coating, characterized in that: It is prepared from the following components in parts by mass: 60-70 parts of modified acrylic resin, 2-5 parts of photoinitiator, 30-40 parts of diluent, 0.5-1.5 parts of antibacterial toughening filler, 1-3 parts of adhesion promoter and 0.5-2 parts of leveling agent; The modified acrylic resin is prepared by reacting methyl acrylate, methyl methacrylate, hydroxy acrylate, isobornyl acrylate, lactone monomer, and glycidyl methacrylate as raw materials to obtain an acrylic prepolymer, which is then reacted with rosin-modified acrylic ester obtained by reacting rosin pentaerythritol ester and glycidyl methacrylate.

2. The UV-curable modified acrylic resin coating according to claim 1, characterized in that: The preparation method of the modified acrylic resin comprises the following steps: S11. Add 50-60 parts by mass of xylene into a reactor, then add 5-10 parts of methyl acrylate, 15-20 parts of methyl methacrylate, 15-20 parts of hydroxy acrylate, 10-15 parts of isobornyl acrylate, 3-5 parts of lactone monomer, 5-8 parts of glycidyl methacrylate and 0.05-1 part of di-tert-butyl peroxide initiator, and heat the reaction to obtain an acrylic acid prepolymer; S12, adding 90-100 parts by mass of rosin pentaerythritol ester to a reactor, and then adding 10-15 parts of glycidyl methacrylate, 1-2 parts of p-methoxyphenol and 1-1.5 parts of triphenylphosphine to react to obtain rosin-modified acrylate; S13. Add 50-60 parts by mass of acrylic prepolymer, 12-14 parts by mass of rosin-modified acrylate, and 0.05-1 part by mass of di-tert-butyl peroxide initiator into a reactor to react and obtain a modified acrylic resin.

3. The UV-curable modified acrylic resin coating according to claim 1, characterized in that: The photoinitiator is any one of photoinitiator 1173 and photoinitiator 819; the diluent is any one of sec-butyl acetate, ethyl acetate, and propylene glycol methyl ether acetate; the adhesion promoter is an acrylic acid phosphate promoter, any one of model FM20 and KM2106; the leveling agent model is any one of BYK-333 and BYK-331.

4. The UV-curable modified acrylic resin coating according to claim 2, characterized in that: In the step S11, the temperature is raised to 130-180° C. and the reaction is carried out for 2-4 hours. The lactone monomer is any one of acrylate caprolactone, 2-methylenylbutyrolactone, and 3-methylacrylate-4-butyrolactone. In the step S12, the temperature is raised to 110-130° C. and the reaction is carried out for 2-4 hours. In the step S13, the temperature is raised to 130-180° C. and the reaction is carried out for 2-4 hours.

5. The UV-curable modified acrylic resin coating according to claim 2, characterized in that: The preparation method of the antibacterial toughening filler comprises the following steps: S21. Add 2 to 2.5 parts of zinc nitrate, 0.05 to 0.15 parts of magnesium nitrate, and 0.3 to 0.6 parts of ferrous nitrate to 40 to 50 parts of N,N-dimethylformamide, stir evenly, and then add 100 to 110 parts of 2-methylimidazole and 30 to 40 parts of 2-aminobenzimidazole to a mixed solution, stir to react, and cool to obtain a zeolite framework; S22. Add 0.4-0.6 parts of zeolite framework to 40-60 parts of dopamine hydrochloric acid solution by mass, react at 20-30° C. for 12-18 hours, collect the solid by dialysis to obtain an antibacterial additive, add 1-2 parts of the antibacterial additive to 40-50 parts of deionized water, add 0.3-0.5 parts of Tween-80, and stir to obtain an aqueous phase; S23. Dissolve 4-5 parts of isophorone diisocyanate trimer and 10-15 parts of dioctyl terephthalate in 30-50 parts of ethyl acetate, add 0.01-0.03 parts of dibutyltin dilaurate and 2-4 parts of polyethylene glycol, and carry out prepolymerization to obtain an oil phase. Mix the oil phase and the aqueous phase, stir at a high speed and heat to react, and then add 0.5-2 parts of ethylene glycol to react to obtain an antibacterial toughening filler.

6. The UV-curable modified acrylic resin coating according to claim 5, characterized in that: The molar ratio of zinc nitrate, magnesium nitrate and ferrous nitrate in S21 is 8: (0.5~1): (0.5~1.5). Zinc nitrate, magnesium nitrate and ferrous nitrate are added to N,N-dimethylformamide and stirred evenly, and then quickly added to the mixed solution. The mixture is stirred and reacted at room temperature for 4~6 hours, and then heated to 40~50°C and stirred and reacted for 1~2 hours. After cooling, the solid is collected by filtration and washed with anhydrous ethanol. The dopamine hydrochloric acid solution in S22 is prepared by adding 1.2~2g of tris(hydroxymethyl)aminomethane to 40~50mL of deionized water, adjusting the pH to 8.5 with hydrochloric acid and sodium hydroxide solution, and then adding 0.4~0.5g of dopamine hydrochloride and mixing.

7. The UV-curable modified acrylic resin coating according to claim 5, characterized in that: In the step S23 , the temperature is raised to 40-50° C. for prepolymerization reaction for 5-10 minutes, and the mixture is homogenized and stirred at a speed of 2500-3500 rpm for 5-10 minutes. The temperature is raised to 50-60° C. for reaction for 1-2 hours, and ethylene glycol is added and kept warm for reaction for 1-2 hours.

8. An application of a UV-curable modified acrylic resin coating, characterized in that: For preparing metal protective coating, comprising the following steps: S1, adding modified acrylic resin, diluent, adhesion promoter and antibacterial toughening filler into a stirring tank, adding photoinitiator and leveling agent, and stirring evenly to prepare UV-curable modified acrylic resin coating; S2. Applying resin coating on an aluminum plate and curing it with ultraviolet light to obtain a coating.

9. The use of a UV-curable modified acrylic resin coating according to claim 8, characterized in that: The coating thickness in S2 is 100-200 μm and is cured by ultraviolet light for 30-50 minutes.

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