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: 50 to 60 parts of acrylic copolymer emulsion, 20 to 30 parts of polyethylene wax emulsion, 80 to 100 parts of propylene glycol methyl ether acetate, 5 to 10 parts of dispersing agent, 2 to 5 parts of defoaming agent, 2 to 5 parts of drier, 5 to 10 parts of filler, 15 to 20 parts of nano TiO2-Fe3O4 compound and 5 to 10 parts of light stabilizer. The preparation method comprises the following steps: preparing a base material, and adding auxiliaries to prepare the antibacterial coating. Wherein the antibacterial agent is a TiO2-Fe3O4 compound, Fe3O4 magnetic particles are introduced, on one hand, the antibacterial agent in the overdue coating can be recycled, on the other hand, a light absorption band of the TiO2-Fe3O4 compound is subjected to large-amplitude red shift and enters a visible light region, the light absorption intensity is increased, and the antibacterial coating also has good antibacterial activity under visible light; meanwhile, due to the existence of the light stabilizer, the light stability of the antibacterial agent is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of coating preparation, and in particular to an antibacterial coating and a preparation method thereof. Background Art

[0002] The so-called paint is a viscous liquid that is applied to the surface of the object to be protected or decorated and can firmly adhere to the surface of the coated object; it is usually made of resin, oil, or emulsion as the main material, with corresponding additives as auxiliary materials, and is prepared with organic solvents or water.

[0003] The known coatings do not have antibacterial properties. Especially after some existing coatings are applied, microorganisms are easily bred on the coating surface, resulting in mildew, and the antibacterial properties of the coatings are poor. In addition, in some crowded public places such as hospitals, stations, schools, etc., there are a large number of bacteria in the air that endanger people's health.

[0004] The patent with application number CN113755067A is disclosed, but it still has the following shortcomings: (1) It does not have the function of secondary recovery of antibacterial agents, which will cause certain waste of resources for some expired coatings; (2) Its antibacterial agent has photocatalytic activity only in the ultraviolet wavelength range, and under long-term light exposure, the antibacterial agent is prone to photodegradation, thereby causing antibacterial failure. The patent with application number CN105348972B has the following shortcomings: (1) The antibacterial agent does not have broad-spectrum antibacterial properties and only has antibacterial effects on individual fungi; (2) Its safety, stability, and heat resistance are not high, and its environmental performance is poor. Summary of the invention

[0005] In order to solve the technical problems mentioned in the background technology, the purpose of the present invention is to provide an antibacterial coating and a preparation method thereof, which solves the problem that antibacterial materials at present cannot be reused and photocatalytic antibacterial agents only work in the ultraviolet wavelength range.

[0006] The purpose of the present invention can be achieved through the following technical solutions: An antibacterial coating is prepared from the following raw materials in parts by weight: 50-60 parts of acrylic copolymer emulsion, 20-30 parts of polyethylene wax emulsion, 80-100 parts of propylene glycol methyl ether acetate, 5-10 parts of dispersant, 2-5 parts of defoamer, 2-5 parts of drying agent, 5-10 parts of filler, 15-20 parts of nano TiO2-Fe3O4 composite and 5-10 parts of light stabilizer.

[0007] The antibacterial coating is prepared by the following steps: Step S1, mixing acrylic copolymer emulsion, polyethylene wax emulsion and propylene glycol methyl ether acetate, and stirring at a speed of 400-500 r / min to obtain a mixture 1; Step S2, adding a dispersant, a nano-TiO2-Fe3O4 composite, and a light stabilizer to the mixed material 1 obtained in step S1, and stirring at a speed of 1500-2000 r / min to obtain a mixed material 2; Step S3, adding the defoamer, the drying agent and the filler into the mixture 2 obtained in step S2, and stirring at a speed of 800-900 r / min to obtain the antibacterial coating.

[0008] Furthermore, the dispersant is sodium hexametaphosphate, the defoaming agent is dimethyl silicone oil, the drying agent is copper oxide, and the filler is composed of titanium dioxide and talc in a mass ratio of 5:1.

[0009] Furthermore, the nano-TiO2-Fe3O4 composite is prepared by the following method: Step A1, grind ilmenite into powder, put it in a three-necked flask and add a hydrochloric acid solution with a molar concentration of 12 mol / L, react in a water bath at 80°C for 6 hours, cool to room temperature, filter to obtain a filtrate, add iron powder to the filtrate and stir continuously until the filtrate turns purple-black, filter out excess iron powder, cool to 6°C to precipitate yellow-green crystals, filter under reduced pressure, and the obtained filtrate is the first solution. The filter cake is washed 3 times with deionized water and anhydrous ethanol, respectively, to obtain an intermediate 1.

[0010] The ilmenite component described in step A1 is FeTiO3, and the usage ratio of ilmenite, hydrochloric acid solution with a molar concentration of 12 mol / L and iron powder is 20-25 g: 80-82 ml: 0.4-0.5 g.

[0011] The purpose of adding iron powder to the filtrate in step A1 is to remove a small amount of Fe 3+ Reduction to Fe 2+ .

[0012] In step A1, ilmenite reacts with hydrochloric acid, and intermediate 1 is precipitated after cooling. The reaction equation is as follows:

[0013] Step A2, drop the first solution into boiling water at a rotation speed of 400-500r / min, continue boiling for 30min, filter under reduced pressure to obtain a white precipitate, wash it with a 10% mass fraction dilute sulfuric acid solution and 80°C hot water in sequence, then dry it at 60°C, and then calcine it in a muffle furnace at 800°C for 2h to obtain intermediate 2.

[0014] In step A2, the dosage ratio of the first solution to boiling water is 20-30 mL: 200-300 mL.

[0015] The main component of the first solution in step A2 is TiOCl2, which is added to boiling water to obtain a hydrate by hydrolysis reaction. After calcination, the intermediate 2 is obtained. The reaction equation is as follows:

[0016] The white precipitate in step A2 is titanic acid (H2TiO3). It is washed with dilute sulfuric acid and hot water because titanic acid is insoluble in sulfuric acid and water. The purpose of washing is to remove excess Fe 2+ and HCl.

[0017] Step A3, weigh the intermediate 1, divide it into two parts according to the mass ratio of 1:2, and dissolve them in deionized water respectively. The former is the second solution, and the latter is added with a 10% nitric acid solution and a 30% hydrochloric acid solution by mass fraction and stirred thoroughly to obtain the third solution. The second solution and the third solution are mixed and added to a three-necked flask, and then the intermediate 2 is added. After magnetic stirring at 80°C for 1h, 10% ammonia water by mass fraction is added dropwise to the three-necked flask, the pH value is adjusted to 9-10, and the reaction is carried out in a water bath at 80°C for 2h, and then cooled to room temperature. The magnetic particles are precipitated by a magnet, the supernatant is poured off and filtered, and the magnetic particles are washed with deionized water until the washing liquid is neutral, and dried at 40°C to obtain a nano-TiO2-Fe3O4 composite.

[0018] The molar ratio of intermediate 1, nitric acid, hydrochloric acid and intermediate 2 in step A3 is 4.5:1:3:15.

[0019] The purpose of adding 10% nitric acid solution and 30% hydrochloric acid solution in step A3 is to remove Fe 2+ Oxidized to Fe 3+ , the specific redox reaction formula is:

[0020] In step A3, the magnetic oxide obtained by the reaction of FeCl3, FeCl2 and ammonia water according to the following equation is compounded with the intermediate 2 to obtain a nano-TiO2-Fe3O4 composite. The above reaction equation is as follows:

[0021] Furthermore, the light stabilizer is prepared by the following method: Step B1, add 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 95% ethanol solution to a flask, stir and react at 80°C for 6h, detect the reaction progress by TLC, and rotary evaporate after the raw material point disappears, extract with deionized water and ethyl acetate 3 times, back-extract with saturated sodium bicarbonate solution and saturated saline solution in turn, dry the organic phase with anhydrous sodium sulfate, evaporate to dryness, and recrystallize with 70% ethanol solution to obtain solid compound a.

[0022] In step B1, the dosage ratio of 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 70% ethanol solution is 0.145-0.150 g: 0.153-0.156 g: 0.080-0.084 g: 14-15 mL. In step B1, 2-hydroxy-4-methylacetophenone reacts with hydroxylamine under acidic conditions to obtain compound a, and the reaction equation is as follows:

[0023] The purpose of back extraction with saturated sodium bicarbonate solution and saturated saline solution in step B1 is to remove excess HCl.

[0024] Step B2, nickel acetate is added to DMF and stirred thoroughly, 10% ammonia water is added to adjust the pH to 8-9 to form a mixed solution 1, and compound a is added to dimethyl sulfoxide and stirred thoroughly, and slowly added to the mixed solution 1, and the reaction system is stirred at room temperature for 2 hours, and then 80% hydrochloric acid solution is added to acidify until a precipitate is precipitated, and the precipitate is filtered, and the precipitate is washed 2-3 times with anhydrous ethanol and deionized water in turn, and finally the precipitate is dried at room temperature to obtain a light stabilizer.

[0025] In step B2, the molar ratio of nickel acetate to compound a is 1:2.

[0026] The light stabilizer obtained in step B2 has the following structural formula:

[0027] Beneficial effects of the present invention: The invention prepares an antibacterial coating, which uses acrylic copolymer emulsion as a film-forming substance, polyethylene wax emulsion as a film-forming auxiliary agent, propylene glycol methyl ether acetate as a solvent, dimethyl silicone oil and copper oxide as other auxiliary agents, titanium dioxide and talcum powder as fillers, and adopts a nano TiO2-Fe3O4 complex as an antibacterial agent. TiO2 itself has a photocatalytic antibacterial performance, and becomes magnetic particles after the introduction of Fe3O4, which can be recycled and reused, thus avoiding the waste of expired coating resources, and has high safety, heat resistance and stability, has a large inhibitory effect on both Gram-positive bacteria and Gram-negative bacteria, and has excellent broad-spectrum antibacterial efficacy. The introduction of magnetic Fe3O4 causes the light absorption band of the photocatalytic antibacterial agent TiO2-Fe3O4 complex to undergo a relatively large red shift and enter the visible light region. The intensity of absorbed light also increases significantly, which means that the nano-TiO2-Fe3O4 complex also has good antibacterial activity under sunlight; in the synthesis of nano-TiO2-Fe3O4 complex, the molar ratio of TiO2 to Fe3O4 is controlled to be 10:1, so that the spatial loading form of the two particles is optimized, giving it better photocatalytic activity and repeatability; the talc powder in the filler and the dispersant sodium hexametaphosphate have good anti-agglomeration effect, and they can effectively reduce the agglomeration phenomenon of the nano-TiO2-Fe3O4 complex in the coating; the light stabilizer is a nickel oxime chelate composed of metallic nickel and aromatic oxime, which can produce energy transfer and quench the electronic excited state of TiO2, and can effectively reduce the photodegradation of TiO2 without affecting the photocatalytic activity of TiO2. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] An antibacterial coating is prepared from the following raw materials in parts by weight: 50 parts of acrylic copolymer emulsion, 20 parts of polyethylene wax emulsion, 80 parts of propylene glycol methyl ether acetate, 5 parts of dispersant, 2 parts of defoamer, 2 parts of drying agent, 8 parts of filler, 18 parts of nano-TiO2-Fe3O4 composite, and 10 parts of light stabilizer.

[0031] The antibacterial coating is prepared by the following steps: Step S1, mixing acrylic copolymer emulsion, polyethylene wax emulsion and propylene glycol methyl ether acetate, and stirring at a speed of 400 r / min to obtain a mixture 1; Step S2, adding a dispersant, a nano-TiO2-Fe3O4 composite, and a light stabilizer to the mixed material 1 obtained in step S1, and stirring at a speed of 1500 r / min to obtain a mixed material 2; Step S3, adding the defoamer, the drying agent and the filler into the mixture 2 obtained in step S2, and stirring at a speed of 900 r / min to obtain the antibacterial coating.

[0032] The dispersant is sodium hexametaphosphate, the defoamer is dimethyl silicone oil, the drying agent is copper oxide, and the filler is composed of titanium dioxide and talc in a mass ratio of 5:1.

[0033] The nano-TiO2-Fe3O4 composite is prepared by the following method: Step A1, grind ilmenite into powder, put it in a three-necked flask and add a hydrochloric acid solution with a molar concentration of 12 mol / L, react in a water bath at 80°C for 6 hours, cool to room temperature, filter to obtain a filtrate, add iron powder to the filtrate and stir continuously until the filtrate turns purple-black, filter out excess iron powder, cool to 6°C to precipitate yellow-green crystals, filter under reduced pressure, and the obtained filtrate is the first solution. The filter cake is washed 3 times with deionized water and anhydrous ethanol, respectively, to obtain an intermediate 1.

[0034] In step A1, the usage ratio of ilmenite, hydrochloric acid solution with a molar concentration of 12 mol / L and iron powder is 25 g:82 ml:0.5 g.

[0035] Step A2, drop the first solution into boiling water at a rotation speed of 500r / min, continue boiling for 30min, filter under reduced pressure to obtain a white precipitate, wash it with a 10% mass fraction dilute sulfuric acid solution and 80°C hot water in sequence, then dry it at 60°C, and then calcine it in a muffle furnace at 800°C for 2h to obtain intermediate 2.

[0036] In step A2, the dosage ratio of the first solution to boiling water is 20 mL:200 mL.

[0037] Step A3, weigh the intermediate 1, divide it into two parts according to the mass ratio of 1:2, and dissolve them in deionized water respectively. The former is the second solution, and the latter is added with a 10% nitric acid solution and a 30% hydrochloric acid solution by mass fraction and stirred thoroughly to obtain the third solution. The second solution and the third solution are mixed and added to a three-necked flask, and then the intermediate 2 is added. After magnetic stirring at 80°C for 1h, 10% ammonia water by mass fraction is added dropwise to the three-necked flask, the pH value is adjusted to 10, and the reaction is carried out in a water bath at 80°C for 2h, and then cooled to room temperature. The magnetic particles are precipitated by a magnet, the supernatant is poured off and filtered, and the magnetic particles are washed with deionized water until the washing liquid is neutral, and dried at 40°C to obtain a nano-TiO2-Fe3O4 composite.

[0038] The molar ratio of intermediate 1, nitric acid, hydrochloric acid and intermediate 2 in step A3 is 4.5:1:3:15.

[0039] The light stabilizer is prepared by the following method: Step B1, add 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 95% ethanol solution to a flask, stir and react at 80°C for 6h, detect the reaction progress by TLC, and rotary evaporate after the raw material point disappears, extract with deionized water and ethyl acetate 3 times, back-extract with saturated sodium bicarbonate solution and saturated saline solution in turn, dry the organic phase with anhydrous sodium sulfate, evaporate to dryness, and recrystallize with 70% ethanol solution to obtain solid compound a.

[0040] In step B1, the dosage ratio of 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 70% ethanol solution is 0.150 g: 0.156 g: 0.084 g: 15 ml.

[0041] Step B2, nickel acetate is added to DMF and stirred thoroughly, 10% ammonia water is added to adjust the pH to 9 to form a mixed solution 1, and compound a is added to dimethyl sulfoxide and stirred thoroughly, and slowly added to the mixed solution 1, and the reaction system is stirred at room temperature for 2 hours, and then 80% hydrochloric acid solution is added to acidify until a precipitate is precipitated, and the precipitate is filtered, and the precipitate is washed twice with anhydrous ethanol and deionized water in sequence, and finally the precipitate is dried at room temperature to obtain a light stabilizer.

[0042] In step B2, the molar ratio of nickel acetate to compound a is 1:2.

[0043] Example 2

[0044] An antibacterial coating is prepared from the following raw materials in parts by weight: 60 parts of acrylic copolymer emulsion, 30 parts of polyethylene wax emulsion, 90 parts of propylene glycol methyl ether acetate, 10 parts of dispersant, 4 parts of defoamer, 5 parts of drying agent, 10 parts of filler, 15 parts of nano-TiO2-Fe3O4 composite, and 5 parts of light stabilizer.

[0045] The antibacterial coating is prepared by the following steps: Step S1, mixing acrylic copolymer emulsion, polyethylene wax emulsion and propylene glycol methyl ether acetate, and stirring at a speed of 450 r / min to obtain a mixture 1; Step S2, adding a dispersant, a nano-TiO2-Fe3O4 composite, and a light stabilizer to the mixed material 1 obtained in step S1, and stirring at a speed of 1800 r / min to obtain a mixed material 2; Step S3, adding the defoamer, the drying agent and the filler into the mixture 2 obtained in step S2, and stirring at a speed of 880 r / min to obtain the antibacterial coating.

[0046] The dispersant is sodium hexametaphosphate, the defoamer is dimethyl silicone oil, the drying agent is copper oxide, and the filler is composed of titanium dioxide and talc in a mass ratio of 5:1.

[0047] The nano-TiO2-Fe3O4 composite is prepared by the following method: Step A1, grind ilmenite into powder, put it in a three-necked flask and add a hydrochloric acid solution with a molar concentration of 12 mol / L, react in a water bath at 80°C for 6 hours, cool to room temperature, filter to obtain a filtrate, add iron powder to the filtrate and stir continuously until the filtrate turns purple-black, filter out excess iron powder, cool to 6°C to precipitate yellow-green crystals, filter under reduced pressure, and the obtained filtrate is the first solution. The filter cake is washed 3 times with deionized water and anhydrous ethanol, respectively, to obtain an intermediate 1.

[0048] In step A1, the usage ratio of ilmenite, hydrochloric acid solution with a molar concentration of 12 mol / L and iron powder is 20 g:80 ml:0.4 g.

[0049] Step A2, drop the first solution into boiling water at a rotation speed of 400r / min, continue boiling for 30min, filter under reduced pressure to obtain a white precipitate, wash it with a 10% mass fraction dilute sulfuric acid solution and 80°C hot water in sequence, then dry it at 60°C, and then calcine it in a muffle furnace at 800°C for 2h to obtain intermediate 2.

[0050] In step A2, the ratio of the first solution to boiling water is 25 mL:250 mL.

[0051] Step A3, weigh the intermediate 1, divide it into two parts according to the mass ratio of 1:2, and dissolve them in deionized water respectively. The former is the second solution, and the latter is added with a 10% nitric acid solution and a 30% hydrochloric acid solution by mass fraction and stirred thoroughly to obtain the third solution. The second solution and the third solution are mixed and added to a three-necked flask, and then the intermediate 2 is added. After magnetic stirring at 80°C for 1h, 10% ammonia water by mass fraction is added dropwise to the three-necked flask, the pH value is adjusted to 9, and the reaction is carried out in a water bath at 80°C for 2h, and then cooled to room temperature. The magnetic particles are precipitated by a magnet, the supernatant is poured off and filtered, and the magnetic particles are washed with deionized water until the washing liquid is neutral, and dried at 40°C to obtain a nano-TiO2-Fe3O4 composite.

[0052] The molar ratio of intermediate 1, nitric acid, hydrochloric acid and intermediate 2 in step A3 is 4.5:1:3:15.

[0053] The light stabilizer is prepared by the following method: Step B1, add 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 95% ethanol solution to a flask, stir and react at 80°C for 6h, detect the reaction progress by TLC, and rotary evaporate after the raw material point disappears, extract with deionized water and ethyl acetate 3 times, back-extract with saturated sodium bicarbonate solution and saturated saline solution in turn, dry the organic phase with anhydrous sodium sulfate, evaporate to dryness, and recrystallize with 70% ethanol solution to obtain solid compound a.

[0054] In step B1, the dosage ratio of 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 70% ethanol solution is 0.145 g: 0.153 g: 0.080 g: 14 mL.

[0055] Step B2, nickel acetate is added to DMF and stirred thoroughly, 10% ammonia water is added to adjust the pH to 8 to form a mixed solution 1, and compound a is added to dimethyl sulfoxide and stirred thoroughly, and slowly added to the mixed solution 1, and the reaction system is stirred at room temperature for 2 hours, and then 80% hydrochloric acid solution is added to acidify until a precipitate is precipitated, and the precipitate is filtered, and the precipitate is washed twice with anhydrous ethanol and deionized water in sequence, and finally the precipitate is dried at room temperature to obtain a light stabilizer.

[0056] In step B2, the molar ratio of nickel acetate to compound a is 1:2.

[0057] Example 3

[0058] An antibacterial coating is prepared from the following raw materials in parts by weight: 55 parts of acrylic copolymer emulsion, 25 parts of polyethylene wax emulsion, 100 parts of propylene glycol methyl ether acetate, 8 parts of dispersant, 5 parts of defoamer, 3 parts of drying agent, 5 parts of filler, 20 parts of nano-TiO2-Fe3O4 composite, and 8 parts of light stabilizer.

[0059] The antibacterial coating is prepared by the following steps: Step S1, mixing acrylic copolymer emulsion, polyethylene wax emulsion and propylene glycol methyl ether acetate, and stirring at a speed of 500 r / min to obtain a mixture 1; Step S2, adding a dispersant, a nano-TiO2-Fe3O4 composite, and a light stabilizer to the mixed material 1 obtained in step S1, and stirring at a speed of 2000 r / min to obtain a mixed material 2; Step S3, adding the defoamer, the drying agent and the filler into the mixture 2 obtained in step S2, and stirring at a speed of 800 r / min to obtain the antibacterial coating.

[0060] The dispersant is sodium hexametaphosphate, the defoamer is dimethyl silicone oil, the drying agent is copper oxide, and the filler is composed of titanium dioxide and talc in a mass ratio of 5:1.

[0061] The nano-TiO2-Fe3O4 composite is prepared by the following method: Step A1, grind ilmenite into powder, put it in a three-necked flask and add a hydrochloric acid solution with a molar concentration of 12 mol / L, react in a water bath at 80°C for 6 hours, cool to room temperature, filter to obtain a filtrate, add iron powder to the filtrate and stir continuously until the filtrate turns purple-black, filter out excess iron powder, cool to 6°C to precipitate yellow-green crystals, filter under reduced pressure, and the obtained filtrate is the first solution. The filter cake is washed 3 times with deionized water and anhydrous ethanol, respectively, to obtain an intermediate 1.

[0062] In step A1, the usage ratio of ilmenite, hydrochloric acid solution with a molar concentration of 12 mol / L and iron powder is 22 g:81 ml:0.5 g.

[0063] Step A2, drop the first solution into boiling water at a rotation speed of 450 r / min, continue boiling for 30 minutes, filter under reduced pressure to obtain a white precipitate, wash it with a 10% mass fraction dilute sulfuric acid solution and 80°C hot water in sequence, then dry it at 60°C, and then calcine it in a muffle furnace at 800°C for 2 hours to obtain intermediate 2.

[0064] In step A2, the dosage ratio of the first solution to boiling water is 30 mL:300 mL.

[0065] Step A3, weigh the intermediate 1, divide it into two parts according to the mass ratio of 1:2, and dissolve them in deionized water respectively. The former is the second solution, and the latter is added with a 10% nitric acid solution and a 30% hydrochloric acid solution by mass fraction and stirred thoroughly to obtain the third solution. The second solution and the third solution are mixed and added to a three-necked flask, and then the intermediate 2 is added. After magnetic stirring at 80°C for 1h, 10% ammonia water by mass fraction is added dropwise to the three-necked flask, the pH value is adjusted to 10, and the reaction is carried out in a water bath at 80°C for 2h, and then cooled to room temperature. The magnetic particles are precipitated by a magnet, the supernatant is poured off and filtered, and the magnetic particles are washed with deionized water until the washing liquid is neutral, and dried at 40°C to obtain a nano-TiO2-Fe3O4 composite.

[0066] The molar ratio of intermediate 1, nitric acid, hydrochloric acid and intermediate 2 in step A3 is 4.5:1:3:15.

[0067] The light stabilizer is prepared by the following method: Step B1, add 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 95% ethanol solution to a flask, stir and react at 80°C for 6h, detect the reaction progress by TLC, and rotary evaporate after the raw material point disappears, extract with deionized water and ethyl acetate 3 times, back-extract with saturated sodium bicarbonate solution and saturated saline solution in turn, dry the organic phase with anhydrous sodium sulfate, evaporate to dryness, and recrystallize with 70% ethanol solution to obtain solid compound a.

[0068] In step B1, the dosage ratio of 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 70% ethanol solution is 0.147 g: 0.154 g: 0.082 g: 15 mL.

[0069] Step B2, nickel acetate is added to DMF and stirred thoroughly, 10% ammonia water is added to adjust the pH to 9 to form a mixed solution 1, and compound a is added to dimethyl sulfoxide and stirred thoroughly, and slowly added to the mixed solution 1, and the reaction system is stirred at room temperature for 2 hours, and then 80% hydrochloric acid solution is added to acidify until a precipitate is precipitated, and the precipitate is filtered, and the precipitate is washed 3 times with anhydrous ethanol and deionized water in sequence, and finally the precipitate is dried at room temperature to obtain a light stabilizer.

[0070] In step B2, the molar ratio of nickel acetate to compound a is 1:2.

[0071] Comparative Example 1 Compared with Example 1, no light stabilizer was added in this comparative example, and the remaining steps were the same.

[0072] Comparative Example 2 Compared with Example 2, this comparative example adds Fe3O4 particles to replace the nano-TiO2-Fe3O4 composite, and the remaining steps are the same.

[0073] Comparative Example 3 Compared with Example 3, this comparative example adds nano-TiO2 particles to replace the nano-TiO2-Fe3O4 composite, and the remaining steps are the same.

[0074] The antibacterial properties of the antibacterial coatings prepared in Examples 1-3 and Comparative Examples 1-3 were tested using GB / T21866-2008. The results are shown in Table 1 below: Table 1

[0075] The antibacterial coatings prepared in Examples 1-3 and Comparative Examples 1-3 were respectively and evenly coated on glass culture dishes with a diameter of 5 cm, and dried in the dark at room temperature. The culture dishes were respectively placed in a Q-Sun xenon lamp test box and a QUV ultraviolet accelerated aging test box; the Q-Sun xenon lamp test box can well simulate all spectra of sunlight, and can generate ultraviolet light, visible light and infrared light. With the filter system on the equipment, it can be used to detect the light stability of indoor materials. The QUV ultraviolet accelerated aging test box uses a fluorescent ultraviolet lamp to emit ultraviolet light to accelerate the aging and discoloration of the sample surface; the illumination time was set to 100 h. After the illumination ended, the photolysis degree was observed and ranked according to the degree of yellowing of the surface: Arabic numerals 1-6 represent the photolysis degree of the coating on the surface of the culture dish, and the larger the number, the deeper the photolysis degree.

[0076] The measurement results are shown in the following table: Table 2

[0077] It can be seen from Table 1 that the antibacterial rate of the antibacterial coatings prepared in Examples 1-3 is 99.69-99.82%, and the durable antibacterial rate is 97.35-98.13%. It can be seen from Table 2 that the antibacterial coatings prepared in Examples 1-3 are less prone to photolysis and aging than those in Comparative Examples 1-3; this indicates that the present invention has a good antibacterial effect and good photostability, and can maintain photocatalytic antibacterial activity for a long time under illumination.

[0078] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. An antibacterial coating, characterized in that: The invention comprises the following raw materials in parts by weight: 50-60 parts of acrylic copolymer emulsion, 20-30 parts of polyethylene wax emulsion, 80-100 parts of propylene glycol methyl ether acetate, 5-10 parts of dispersant, 2-5 parts of defoamer, 2-5 parts of drying agent, 5-10 parts of filler, 15-20 parts of nano-TiO2-Fe3O4 compound, and 5-10 parts of light stabilizer; The antibacterial coating is prepared by the following steps: Step S1, mixing acrylic copolymer emulsion, polyethylene wax emulsion and propylene glycol methyl ether acetate, and stirring at a speed of 400-500 r / min to obtain a mixture 1; Step S2, adding a dispersant, a nano-TiO2-Fe3O4 composite, and a light stabilizer to the mixed material 1 obtained in step S1, and stirring at a speed of 1500-2000 r / min to obtain a mixed material 2; Step S3, adding the defoamer, the drying agent and the filler into the mixture 2 obtained in step S2, and stirring at a speed of 800-900 r / min to obtain the antibacterial coating.

2. An antibacterial coating according to claim 1, characterized in that: The dispersant is sodium hexametaphosphate, the defoamer is dimethyl silicone oil, the drying agent is copper oxide, and the filler is composed of titanium dioxide and talc in a mass ratio of 5:

1.

3. The antibacterial coating according to claim 1, characterized in that: The preparation method of the nano TiO2-Fe3O4 composite is as follows: Step A1, grind ilmenite into powder, put it in a three-necked flask and add a hydrochloric acid solution with a molar concentration of 12 mol / L, react in a water bath at 80°C for 6 hours, cool to room temperature, filter to obtain a filtrate, add iron powder to the filtrate and stir continuously until the filtrate turns purple-black, filter out excess iron powder, cool to 6°C to precipitate crystals, filter under reduced pressure, and the obtained filtrate is the first solution. The filter cake is washed 3 times with deionized water and anhydrous ethanol respectively to obtain an intermediate 1; Step A2, taking the first solution and dropping it into boiling water at a rotation speed of 400-500r / min, continuing to boil for 30min, filtering under reduced pressure to obtain a white precipitate, washing it with a 10% mass fraction dilute sulfuric acid solution and 80°C hot water in sequence, then drying it at 60°C, and then calcining it in a muffle furnace at 800°C for 2h to obtain an intermediate 2; Step A3, weigh the intermediate 1, divide it into two parts according to the mass ratio of 1:2, dissolve them in deionized water respectively, the former is the second solution, add 10% nitric acid solution by mass and 30% hydrochloric acid solution by mass to the latter and stir them thoroughly to obtain the third solution, mix the second solution and the third solution and add them into a three-necked flask, then add the intermediate 2, stir magnetically at 80°C for 1h, add 10% ammonia water dropwise into the three-necked flask, adjust the pH value to 9-10, react in a water bath at 80°C for 2h, cool to room temperature, precipitate magnetic particles, pour off the supernatant and filter, wash the magnetic particles with deionized water until the washing liquid is neutral, and dry at 40°C to obtain a nano-TiO2-Fe3O4 composite.

4. An antibacterial coating according to claim 3, characterized in that: In step A1, the dosage ratio of ilmenite, hydrochloric acid solution and iron powder is controlled to be 20-25 g: 80-82 mL: 0.4-0.5 g.

5. The antibacterial coating according to claim 3, characterized in that: In step A2, the dosage ratio of the first solution to boiling water is controlled to be 20-30 mL: 200-300 mL.

6. The antibacterial coating according to claim 3, characterized in that: In step A3, the molar ratio of intermediate 1, nitric acid, hydrochloric acid and intermediate 2 is controlled to be 4.5:1:3:

15.

7. The antibacterial coating according to claim 1, characterized in that: The light stabilizer preparation method is: Step B1, add 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 95% ethanol solution to a flask, stir at 80°C for 6h, detect the reaction progress by TLC, and after the raw material point disappears, perform rotary evaporation, extract with deionized water and ethyl acetate for 3 times, back-extract with saturated sodium bicarbonate solution and saturated saline solution in turn, dry the organic phase with anhydrous sodium sulfate, evaporate to dryness, and recrystallize with 70% ethanol solution to obtain solid compound a; Step B2, nickel acetate is added to DMF and stirred thoroughly, 10% ammonia water is added to adjust the pH to 8-9 to form a mixed solution 1, and compound a is added to dimethyl sulfoxide and stirred thoroughly, and slowly added to the mixed solution 1, and the reaction system is stirred at room temperature for 2 hours, and then 80% hydrochloric acid solution is added to acidify until a precipitate is precipitated, and the precipitate is filtered, and the precipitate is washed 2-3 times with anhydrous ethanol and deionized water in turn, and finally the precipitate is dried at room temperature to obtain a light stabilizer.

8. An antibacterial coating according to claim 7, characterized in that: In step B1, the dosage ratio of 2-hydroxy-4-methylacetophenone, sodium acetate trihydrate, hydroxylamine hydrochloride and 95% ethanol solution is controlled to be 0.145-0.150 g: 0.153-0.156 g: 0.080-0.084 g: 14-15 mL.

9. The antibacterial coating according to claim 7, characterized in that: In step B2, the molar ratio of nickel acetate to compound a is controlled to be 1:

2.

10. The method for preparing an antibacterial coating according to claim 1, characterized in that: The steps include: Step S1, mixing acrylic copolymer emulsion, polyethylene wax emulsion and propylene glycol methyl ether acetate, and stirring at a speed of 400-500 r / min to obtain a mixture 1; Step S2, adding a dispersant, a nano-TiO2-Fe3O4 composite, and a light stabilizer to the mixed material 1 obtained in step S1, and stirring at a speed of 1500-2000 r / min to obtain a mixed material 2; Step S3, adding the defoamer, the drying agent and the filler into the mixture 2 obtained in step S2, and stirring at a speed of 800-900 r / min to obtain the antibacterial coating.

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