Antibacterial mildew-proof environment-friendly water-based paint and preparation method thereof

Abstract

The invention discloses antibacterial and mildew-proof environment-friendly water-based paint and a preparation method thereof, and belongs to the technical field of water-based paint preparation. The antibacterial and mildew-proof environment-friendly water-based paint is prepared from the following components in parts by weight: 30 to 50 parts of acrylic resin, 2 to 4 parts of titanium dioxide, 1 to 3 parts of a de-foaming agent, 1.2 to 1.8 parts of a flatting agent, 1 to 1.4 parts of a dispersing agent, 1.1 to 1.7 parts of a coalescing agent, 8 to 12 parts of composite nanofiber, 1 to 5 parts of an antibacterial and mildew-proof agent and 70 to 80 parts of de-ionized water. The composite nanofibers and the antibacterial and mildew-proof agent are added into the coating, so that the antibacterial and mildew-proof properties and the environmental protection property of the coating can be effectively improved, and the environmental protection property of the coating can be effectively improved by using the deionized water.

Description

Technical Field

[0001] The invention belongs to the technical field of water-based paint preparation, and specifically relates to an antibacterial and mildew-proof environmentally friendly water-based paint and a preparation method thereof. Background Art

[0002] With the development of the construction industry, paint, as an important material for indoor and outdoor decoration, has an increasingly wide range of applications. However, traditional paints often produce a lot of environmental pollution during production and use, such as the emission of volatile organic compounds, which not only has a serious impact on the ecological environment, but also poses a potential threat to human health. And with the improvement of people's living standards and the enhancement of health awareness, the hygienic requirements for living and working environments are getting higher and higher. Especially in public places such as hospitals, schools, and food processing plants. These microorganisms not only affect the beauty and comfort of the environment, but may also cause various diseases, posing a threat to people's health.

[0003] Therefore, antibacterial and mildew-proof environmentally friendly water-based paint came into being. This kind of paint uses water-based resin as the base material and adds antibacterial agents and other materials to make it have excellent antibacterial and mildew-proof properties. Compared with traditional solvent-based paints, environmentally friendly water-based paints have lower VOCs emissions, better environmental performance and lower health risks. At the same time, its antibacterial and mildew-proof properties can effectively inhibit the growth of bacteria and mold, providing people with a healthier and safer living and working environment.

[0004] Patent CN 109777161 A discloses an environmentally friendly water-based paint and a preparation method thereof. The mass percentages of the components of the environmentally friendly water-based paint are as follows: white carbon black 13.9-19.2%, quicklime 2-3.3%, kaolin 1.7-2.5%, glutinous rice flour 2.5-3.2%, and water 73-78%. The preparation method of the environmentally friendly water-based paint is as follows: weigh glutinous rice flour and water in a container and steam to obtain glutinous rice paste; weigh white carbon black, quicklime, kaolin and water and mix them with the cooked glutinous rice paste to obtain a mixed liquid; put the mixed liquid into a stirrer and stir and mix evenly until the surface of the mixed liquid is uniform and there is no precipitation at the bottom to obtain an environmentally friendly water-based paint. The environmentally friendly water-based paint prepared by this method has easy-to-obtain raw materials, simple preparation, non-toxic and pollution-free, but the antibacterial and mildew-proof effect, weather resistance and environmental protection performance of the water-based paint prepared by this method still have room for improvement. Summary of the invention

[0005] The purpose of the present invention is to provide an antibacterial and mildew-proof environmentally friendly water-based paint and a preparation method thereof, so as to solve the technical problems of poor antibacterial and mildew-proof, weather resistance and environmental protection performance of water-based paint in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The invention provides an antibacterial and mildewproof environment-friendly water-based paint, which is composed of the following components in parts by weight: 30-50 parts of acrylic resin, 2-4 parts of titanium dioxide, 1-3 parts of defoaming agent, 1.2-1.8 parts of leveling agent, 1-1.4 parts of dispersant, 1.1-1.7 parts of film-forming aid, 8-12 parts of composite nanofibers, 1-5 parts of antibacterial and mildewproof agent, and 70-80 parts of deionized water, wherein the composite nanofibers are prepared from 1-vinyl-3-ethylimidazole bromide, 3-butenenitrile, triethylamine and N,N-dimethylformamide, and the antibacterial and mildewproof agent is prepared from 1-allylimidazole, 2-bromoethylamine hydrobromide and divinylbenzene.

[0008] Preferably, the method for preparing the composite nanofiber comprises the following steps:

[0009] Q1: Add 1-vinyl-3-ethylimidazolium bromide and azobisisobutyronitrile to a container, then add 3-butenenitrile, and then continue to add N,N-dimethylformamide, stir to dissolve, expel air, introduce nitrogen, heat and magnetically stir, and after the reaction is completed, obtain a reaction liquid, take another clean container, pour isopropanol, and drop the reaction liquid into the isopropanol under stirring. Solids are generated during the dropwise addition. After the dropwise addition is completed, filter with a vacuum pump, wash, and dry to obtain intermediate product 1;

[0010] Q2: Add the intermediate product 1 and triethylamine into a container, then add N,N-dimethylformamide, stir to dissolve, heat to react, and after the reaction is completed, precipitate the product with isopropanol, vacuum filter, wash, and dry to obtain the intermediate product 2;

[0011] Q3: The intermediate product 2 is dissolved in N,N-dimethylformamide, stirred to dissolve, and a spinning solution is obtained. The nanofibers are obtained by electrospinning technology, and the composite nanofibers are obtained after constant temperature drying.

[0012] In the above process, 1-vinyl-3-ethylimidazolium bromide and 3-butenenitrile are used as an initiator and isopropanol as a solvent to obtain intermediate product 1, and then intermediate product 1 undergoes hydroxylation reaction with triethylamine to obtain intermediate product 2. Intermediate product 2 is mixed with N,N-dimethylformamide and composite nanofibers are obtained by electrospinning. The preparation process of intermediate product 2 is as follows:

[0013]

[0014] Preferably, in Q1, the molar ratio of 1-vinyl-3-ethylimidazolium bromide to 3-butenenitrile is 1:(0.8-1.2), the heating magnetic stirring temperature is 80-85°C, the time is 8-10h, it is washed with isopropanol 3-5 times, and the drying temperature is 70-80°C for 10-12h.

[0015] Preferably, in Q2, the molar ratio of the intermediate product 1 and triethylamine is (0.9-1.2): (0.8-1.2), the heating temperature is 70-75°C, the reaction time is 8-10h, washed with isopropanol 3-5 times, the drying temperature is 70-80°C, and the time is 10-12h; in Q3, the amount ratio of the intermediate product 2 and N,N-dimethylformamide is (3-5)g: (10-16)mL, the drying temperature is 70-75°C, and the time is 20-24h.

[0016] Preferably, the method for preparing the antibacterial and mildew-proof agent comprises the following steps:

[0017] S1: adding 1-allylimidazole to acetonitrile, stirring and adding 2-bromoethylamine hydrobromide, heating under reflux for reaction after fully dissolving, and after the reaction is completed, rotary evaporation, washing, and vacuum drying are performed to obtain a functionalized imidazole salt;

[0018] S2: dissolving the functionalized imidazole salt in a container containing a mixed solution of ethanol and deionized water, adding divinylbenzene, heating the system under a nitrogen environment, slowly adding azobisisobutyronitrile, and after the reaction, filtering, separating, washing, and drying to obtain a functionalized imidazole powder;

[0019] S3: dissolving the functionalized imidazole powder in a sodium hydroxide solution, stirring, centrifugally filtering, washing, stirring, filtering, and washing to obtain an antibacterial and antifungal agent.

[0020] In the above process, 1-allylimidazole is added to acetonitrile, stirred and dissolved, and 2-bromoethylamine hydrobromide is added. Since the substance has strong acidity, bromide ions are generated. The bromide ions act as leaving groups and undergo nucleophilic substitution reaction with the nitrogen atom of 1-allylimidazole to generate functionalized imidazole salts. In a nitrogen environment, azobisisobutyronitrile acts as a free radical initiator to initiate a free radical polymerization reaction between divinylbenzene and the functionalized imidazole salt to obtain functionalized imidazole powder. Finally, the alkalinity of sodium hydroxide is used to neutralize the hydrobromide ions in the functionalized imidazole salt to generate an antibacterial and antifungal agent. The preparation process of the antibacterial and antifungal agent is as follows:

[0021]

[0022] Preferably, in S1, the molar ratio of 1-allylimidazole, acetonitrile and 2-bromoethylamine hydrobromide is (0.2-0.4):(1-2):(0.22-0.44), the heating reflux reaction temperature is 70-80°C, the time is 48-52h, the rotary evaporation temperature is 50-55°C, washing is carried out with ethyl acetate, and the vacuum drying temperature is 60-70°C, and the time is 7-8d.

[0023] Preferably, in S2, the dosage ratio of the functionalized imidazole salt, ethanol, deionized water, divinylbenzene and azobisisobutyronitrile is (8-12) g: (30-45) mL: (10-15) mL: (4.9-6.13) mL: (0.13-0.35) g, the heating temperature is 80-83°C, the reaction time is 10-12 h, and the mixture is washed with a mixed solution of ethanol and deionized water in a volume ratio of 3:1; in S3, the dosage ratio of the functionalized imidazole powder and the sodium hydroxide solution is (10-18) g: (20-25) mL, the volume fraction of the sodium hydroxide solution is 50 vt%, the stirring time is 3-4 d, and an acetic acid aqueous solution with a volume fraction of 30 vt% is added and stirred for 2-4 d.

[0024] Preferably, the method for preparing the antibacterial and mildew-proof environmentally friendly water-based coating comprises the following steps:

[0025] Step (1): adding acrylic resin to deionized water and stirring, then adding a defoamer, a leveling agent, and a film-forming aid, and finally adding titanium dioxide, and stirring to obtain a mixed solution;

[0026] Step (2): Add composite nanofibers, antibacterial and mildew-proof agent and dispersant to deionized water in sequence, stir thoroughly, pour into the mixed solution, continue stirring, and let stand to obtain antibacterial and mildew-proof environmentally friendly water-based paint.

[0027] Preferably, in step (1), the stirring time is 10-15 min, and the stirring time is 30-45 min; in step (2), the stirring time is 10-15 min, the continued stirring time is 30-40 min, and the standing time is 20-40 min.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0029] 1. The present invention firstly uses 1-vinyl-3-ethylimidazole bromide, 3-butenenitrile and triethylamine as raw materials to synthesize composite nanofibers, then uses 1-allylimidazole, 2-bromoethylamine hydrobromide and divinylbenzene as raw materials to synthesize antibacterial and mildew-proof agents, and adds the obtained composite nanofibers and antibacterial and mildew-proof agents as additives to water-based paint, so that the obtained water-based paint has excellent antibacterial and mildew-proof properties and weather resistance. Deionized water is used as a main solvent, which can effectively reduce the accumulation and precipitation of ions in the paint, avoid reaction with organic matter, improve the stability of the paint, and also reduce the emission of volatile organic compounds, improve the environmental performance of the paint, thereby improving the use range and service life of the paint.

[0030] 2. The present invention uses 1-vinyl-3-ethylimidazolium bromide, 3-butenenitrile, triethylamine and N,N-dimethylformamide as raw materials, and obtains composite nanofibers through electrospinning technology. Adding the composite nanofibers to water-based coatings can effectively improve the weather resistance and antibacterial and mildew-proof properties of the coatings. The composite nanofibers can form a dense protective layer in the coatings, reduce the direct contact between the coatings and the external environment, and reduce the corrosion of the coatings by ultraviolet rays, moisture and oxygen. The high specific surface area and nanosize effect of the composite nanofibers can enhance the mechanical properties of the coatings and increase the durability of the coatings in outdoor environments. The prepared composite nanofibers have an antibacterial effect, and the high specific surface area can interfere with the cell membranes of bacteria and molds, affecting their metabolism and growth. The tiny size of the composite nanofibers enables them to penetrate the cell walls of bacteria and molds, further destroy the cell structure, and enhance the antibacterial and mildew-proof properties.

[0031] 3. The present invention uses 1-allylimidazole, 2-bromoethylamine hydrobromide, divinylbenzene and sodium hydroxide as raw materials to obtain an antibacterial and mildew-proof agent, which can be added to a coating to effectively improve the antibacterial and mildew-proof properties of the coating. The imidazole ring in the antibacterial and mildew-proof agent is an effective antibacterial group. When bacteria come into contact with the antibacterial and mildew-proof agent, the imidazole ring can destroy the cell wall or cell membrane of the bacteria, causing leakage of cell contents, thereby killing the bacteria; it can also destroy the cell membrane of molds, causing mold cell death; inhibit the respiration and enzymatic reaction of molds, so that the molds cannot obtain the energy and substances required for growth, and at the same time can change the microenvironment on the surface of the coating, so that the molds cannot grow and reproduce on its surface, thereby achieving the antibacterial and mildew-proof effect. DETAILED DESCRIPTION

[0032] 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 the embodiments. 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.

[0033] The chemical reagents used in the embodiments and comparative examples are all commercially available products, and the manufacturers and CAS numbers are as follows:

[0034] 1-Vinyl-3-ethylimidazolium bromide was purchased from Wuhan Kamik Technology Co., Ltd., CAS No.: 81517-60-4;

[0035] Azobisisobutyronitrile was purchased from Zibo Tongyizhai Chemical Co., Ltd., CAS No.: 78-67-1;

[0036] 3-Butenenitrile was purchased from Wuhan Jixinyibang Biotechnology Co., Ltd., CAS No.: 109-75-1;

[0037] N,N-dimethylformamide was purchased from Shanghai Denuo Chemical Co., Ltd., CAS number: 68-12-2;

[0038] Isopropyl alcohol was purchased from Suzhou Qianan Chemical Raw Materials Co., Ltd., CAS No.: 67-63-0;

[0039] Triethylamine was purchased from Shandong Chuxin Chemical Co., Ltd., CAS No.: 121-44-8;

[0040] 1-Allyl imidazole was purchased from Hubei Xinghengye Technology Co., Ltd., CAS No.: 31410-01-2;

[0041] Acetonitrile was purchased from Jinan Liyang Chemical Co., Ltd., CAS No.: 75-05-8;

[0042] 2-Bromoethylamine hydrobromide was purchased from Hubei Xingyan New Material Technology Co., Ltd., CAS No.: 2576-47-8;

[0043] Ethyl acetate was purchased from Wuxi Haomiao Chemical Technology Co., Ltd., CAS No.: 141-78-6;

[0044] Ethanol was purchased from Shanghai Kelong Chemical Co., Ltd., CAS No.: 64-17-5;

[0045] Divinylbenzene was purchased from Shandong New Kinetic Energy Chemical Co., Ltd., CAS No.: 1321-74-0;

[0046] Sodium hydroxide was purchased from Langfang Pengcai Fine Chemical Co., Ltd., CAS No.: 1310-73-2;

[0047] Acetic acid was purchased from Shanghai Denuo Chemical Co., Ltd., CAS No.: 64-19-7;

[0048] Acrylic resin was purchased from Hebei Guansen Anticorrosive Materials Co., Ltd., CAS No.: 9003-01-4;

[0049] Titanium dioxide was purchased from Langfang Lanke Chemical Co., Ltd., CAS No.: 13463-67-7;

[0050] The defoamer was purchased from Shandong Kemi Chemical Co., Ltd.;

[0051] The leveling agent was purchased from Laiyang Shengbang Silicone Technology Co., Ltd.;

[0052] The dispersant was purchased from Qingdao Enze Chemical Co., Ltd.;

[0053] The film-forming aids were purchased from Shanghai Tichem Industrial Co., Ltd.

[0054] Embodiment 1: This embodiment discloses a method for preparing composite nanofibers, comprising the following steps:

[0055] Q1: Add 3.54 g of 1-vinyl-3-ethylimidazolium bromide and azobisisobutyronitrile to a container, then add 1.25 g of 3-butenenitrile, and then continue to add N,N-dimethylformamide, stir to dissolve, expel air, introduce nitrogen, heat at 80°C with magnetic stirring for 10 h, and after the reaction is completed, obtain a reaction liquid, take another clean container, pour isopropanol, and add the reaction liquid dropwise to the isopropanol under stirring. Solids are generated during the dropwise addition. After the dropwise addition is completed, filter with a vacuum pump, wash with isopropanol 3 times, and dry at 80°C for 10 h to obtain intermediate product 1;

[0056] Q2: 3 g of intermediate product 1 and 1.25 g of triethylamine were added to a container, and then N,N-dimethylformamide was added, stirred to dissolve, and heated at 75°C for 10 h. After the reaction was completed, the product was precipitated with isopropanol, vacuum filtered, washed with isopropanol 3 times, and dried at 80°C for 10 h to obtain intermediate product 2;

[0057] Q3: Dissolve 4 g of intermediate product 2 in 13 mL of N,N-dimethylformamide, stir and dissolve to obtain a spinning solution, use electrospinning technology to obtain nanofibers, and dry at 75°C for 24 hours to obtain composite nanofibers.

[0058] This embodiment discloses a method for preparing an antibacterial and mildew-proof agent, comprising the following steps:

[0059] S1: Add 1.5 mL of 1-allylimidazole to 3.63 mL of acetonitrile, stir and add 1.63 mL of 2-bromoethylamine hydrobromide, heat under reflux at 80 °C for 48 h after fully dissolving, and after the reaction is completed, perform rotary evaporation at 55 °C, wash with ethyl acetate, and vacuum dry at 70 °C for 8 d to obtain a functionalized imidazole salt;

[0060] S2: Dissolve 10 g of functionalized imidazole salt in a container containing a mixed solution of 37.5 mL of ethanol and 12.5 mL of deionized water, add 5.52 mL of divinylbenzene, raise the temperature of the system to 80 ° C under a nitrogen environment, slowly add 0.24 g of azobisisobutyronitrile, react for 12 hours, filter and separate, wash with a mixed solution of ethanol and deionized water in a volume ratio of 3:1, and dry to obtain functionalized imidazole powder;

[0061] S3: Dissolve 14 g of functionalized imidazole powder in 22.5 mL of 50 vt% sodium hydroxide solution, stir for 4 days, centrifuge and filter, wash, add 30 vt% acetic acid aqueous solution and stir for 3 days, filter and wash to obtain an antibacterial and antifungal agent.

[0062] The present embodiment discloses an antibacterial and mildewproof environmentally friendly water-based paint, which is composed of the following ingredients in parts by weight: 40 parts of acrylic resin, 3 parts of titanium dioxide, 2 parts of defoaming agent, 1.5 parts of leveling agent, 1.2 parts of dispersant, 1.4 parts of film-forming aid, 10 parts of composite nanofibers, 3 parts of antibacterial and mildewproof agent, and 75 parts of deionized water.

[0063] This embodiment discloses a method for preparing an antibacterial and mildew-proof environmentally friendly water-based coating, comprising the following steps:

[0064] Step (1): add acrylic resin to 50 parts of deionized water and stir for 15 minutes, then add defoamer, leveling agent, film-forming aid, and finally add titanium dioxide, stir for 45 minutes to obtain a mixed solution;

[0065] Step (2): Add composite nanofibers, antibacterial and mildew-proof agent and dispersant to 25 parts of deionized water in sequence, stir for 15 minutes, pour into the mixed solution and continue stirring for 40 minutes, let stand for 30 minutes, and obtain antibacterial and mildew-proof environmentally friendly water-based coating.

[0066] Embodiment 2: This embodiment discloses a method for preparing composite nanofibers, comprising the following steps:

[0067] Q1: Add 3.54 g of 1-vinyl-3-ethylimidazolium bromide and azobisisobutyronitrile to a container, then add 1 g of 3-butenenitrile, and then continue to add N,N-dimethylformamide, stir to dissolve, expel air, introduce nitrogen, heat at 80°C with magnetic stirring for 10 h, and after the reaction is completed, obtain a reaction liquid, take another clean container, pour isopropanol, and add the reaction liquid dropwise to the isopropanol under stirring. Solids are generated during the dropwise addition. After the dropwise addition is completed, filter with a vacuum pump, wash with isopropanol 3 times, and dry at 80°C for 10 h to obtain intermediate 1;

[0068] Q2: Add 2.57 g of intermediate product 1 and 1.0 g of triethylamine to a container, then add N,N-dimethylformamide, stir to dissolve, heat to react at 75°C for 10 h, and after the reaction, precipitate the product with isopropanol, vacuum filter, wash with isopropanol 3 times, and dry at 80°C for 10 h to obtain intermediate product 2;

[0069] Q3: Dissolve 3 g of intermediate product 2 in 10 mL of N,N-dimethylformamide and stir to dissolve to obtain a spinning solution. Use electrospinning technology to obtain nanofibers. Dry at 75°C for 24 hours to obtain composite nanofibers.

[0070] This embodiment discloses a method for preparing an antibacterial and mildew-proof agent, comprising the following steps:

[0071] S1: Add 1 mL of 1-allylimidazole to 2.42 mL of acetonitrile, stir, add 1.09 mL of 2-bromoethylamine hydrobromide, heat under reflux at 80 °C for 48 h after fully dissolving, and after the reaction is completed, perform rotary evaporation at 55 °C, wash with ethyl acetate, and vacuum dry at 70 °C for 8 d to obtain a functionalized imidazole salt;

[0072] S2: 8 g of functionalized imidazole salt was dissolved in a container containing a mixed solution of 30 mL of ethanol and 10 mL of deionized water, and 4.9 mL of divinylbenzene was added. The temperature of the system was raised to 80 ° C under a nitrogen environment, and 0.13 g of azobisisobutyronitrile was slowly added. After reacting for 12 hours, the mixture was filtered and separated, and washed with a mixed solution of ethanol and deionized water in a volume ratio of 3:1, and dried to obtain functionalized imidazole powder;

[0073] S3: Dissolve 10 g of functionalized imidazole powder in 20 mL of 50 vt% sodium hydroxide solution, stir for 4 days, centrifuge and filter, wash, add 30 vt% acetic acid aqueous solution and stir for 3 days, filter and wash to obtain an antibacterial and antifungal agent.

[0074] The present embodiment discloses an antibacterial and mildewproof environmentally friendly water-based paint, which is composed of the following ingredients in parts by weight: 30 parts of acrylic resin, 2 parts of titanium dioxide, 1 part of defoaming agent, 1.2 parts of leveling agent, 1 part of dispersant, 1.1 parts of film-forming aid, 8 parts of composite nanofibers, 1 part of antibacterial and mildewproof agent, and 80 parts of deionized water.

[0075] This embodiment discloses a method for preparing an antibacterial and mildew-proof environmentally friendly water-based coating, comprising the following steps:

[0076] Step (1): add acrylic resin to 55 parts of deionized water and stir for 15 minutes, then add defoamer, leveling agent, film-forming aid, and finally add titanium dioxide, stir for 45 minutes to obtain a mixed solution;

[0077] Step (2): Add composite nanofibers, antibacterial and mildew-proof agent and dispersant to 25 parts of deionized water in sequence, stir for 15 minutes, pour into the mixed solution and continue stirring for 40 minutes, let stand for 30 minutes, and obtain antibacterial and mildew-proof environmentally friendly water-based coating.

[0078] Embodiment 3: This embodiment discloses a method for preparing composite nanofibers, comprising the following steps:

[0079] Q1: Add 3.54 g of 1-vinyl-3-ethylimidazolium bromide and azobisisobutyronitrile to a container, then add 1.5 g of 3-butenenitrile, and then continue to add N,N-dimethylformamide, stir to dissolve, expel air, introduce nitrogen, heat at 80°C with magnetic stirring for 10 h, and after the reaction is completed, obtain a reaction liquid, take another clean container, pour isopropanol, and add the reaction liquid dropwise to the isopropanol under stirring. Solids are generated during the dropwise addition. After the dropwise addition is completed, filter with a vacuum pump, wash with isopropanol 3 times, and dry at 80°C for 10 h to obtain intermediate product 1;

[0080] Q2: 3.43 g of intermediate product 1 and 1.5 g of triethylamine were added to a container, and then N,N-dimethylformamide was added, stirred to dissolve, and heated at 75°C for 10 h. After the reaction was completed, the product was precipitated with isopropanol, vacuum filtered, washed with isopropanol 3 times, and dried at 80°C for 10 h to obtain intermediate product 2;

[0081] Q3: Dissolve 5 g of intermediate product 2 in 16 mL of N,N-dimethylformamide, stir and dissolve to obtain a spinning solution, use electrospinning technology to obtain nanofibers, and dry at 75°C for 24 hours to obtain composite nanofibers.

[0082] This embodiment discloses a method for preparing an antibacterial and mildew-proof agent, comprising the following steps:

[0083] S1: Add 2 mL of 1-allylimidazole to 4.84 mL of acetonitrile, stir and add 2.18 mL of 2-bromoethylamine hydrobromide, heat under reflux at 80 °C for 48 h after fully dissolving, and after the reaction is completed, perform rotary evaporation at 55 °C, wash with ethyl acetate, and vacuum dry at 70 °C for 8 d to obtain a functionalized imidazole salt;

[0084] S2: 12 g of functionalized imidazole salt was dissolved in a container containing a mixed solution of 45 mL of ethanol and 15 mL of deionized water, and 6.13 mL of divinylbenzene was added. The temperature of the system was raised to 80 ° C under a nitrogen environment, and 0.35 g of azobisisobutyronitrile was slowly added. After reacting for 12 hours, the mixture was filtered and separated, washed with a mixed solution of ethanol and deionized water in a volume ratio of 3:1, and dried to obtain functionalized imidazole powder;

[0085] S3: Dissolve 18 g of functionalized imidazole powder in 25 mL of 50 vt% sodium hydroxide solution, stir for 4 days, centrifuge and filter, wash, add 30 vt% acetic acid aqueous solution and stir for 3 days, filter and wash to obtain an antibacterial and antifungal agent.

[0086] The present embodiment discloses an antibacterial and mildewproof environmentally friendly water-based paint, which is composed of the following ingredients in parts by weight: 50 parts of acrylic resin, 4 parts of titanium dioxide, 3 parts of defoaming agent, 1.8 parts of leveling agent, 1.4 parts of dispersant, 1.7 parts of film-forming aid, 12 parts of composite nanofibers, 5 parts of antibacterial and mildewproof agent, and 70 parts of deionized water.

[0087] This embodiment discloses a method for preparing an antibacterial and mildew-proof environmentally friendly water-based coating, comprising the following steps:

[0088] Step (1): add acrylic resin to 50 parts of deionized water and stir for 15 minutes, then add defoamer, leveling agent, film-forming aid, and finally add titanium dioxide, stir for 45 minutes to obtain a mixed solution;

[0089] Step (2): Add composite nanofibers, antibacterial and mildew-proof agent and dispersant to 20 parts of deionized water in sequence, stir for 15 minutes, pour into the mixed solution and continue stirring for 40 minutes, let stand for 30 minutes, and obtain antibacterial and mildew-proof environmentally friendly water-based coating.

[0090] Embodiment 4: This embodiment discloses a method for preparing composite nanofibers, comprising the following steps:

[0091] Q1: Add 3.54 g of 1-vinyl-3-ethylimidazolium bromide and azobisisobutyronitrile to a container, then add 1.3 g of 3-butenenitrile, and then continue to add N,N-dimethylformamide, stir to dissolve, expel air, introduce nitrogen, heat at 80°C with magnetic stirring for 10 h, and after the reaction is completed, obtain a reaction liquid, take another clean container, pour isopropanol, and add the reaction liquid dropwise to the isopropanol under stirring. Solids are generated during the dropwise addition. After the dropwise addition is completed, filter with a vacuum pump, wash with isopropanol 3 times, and dry at 80°C for 10 h to obtain intermediate product 1;

[0092] Q2: 3.08 g of intermediate product 1 and 1.3 g of triethylamine were added to a container, and then N,N-dimethylformamide was added, stirred to dissolve, and heated at 75°C for 10 h. After the reaction was completed, the product was precipitated with isopropanol, vacuum filtered, washed with isopropanol 3 times, and dried at 80°C for 10 h to obtain intermediate product 2;

[0093] Q3: Dissolve 3.7 g of intermediate product 2 in 12 mL of N,N-dimethylformamide, stir and dissolve to obtain a spinning solution, use electrospinning technology to obtain nanofibers, and dry at 75°C for 24 hours to obtain composite nanofibers.

[0094] This embodiment discloses a method for preparing an antibacterial and mildew-proof agent, comprising the following steps:

[0095] S1: Add 1.7 mL of 1-allylimidazole to 3.97 mL of acetonitrile, stir and add 2.07 mL of 2-bromoethylamine hydrobromide, heat under reflux at 80 °C for 48 h after fully dissolving, and after the reaction is completed, perform rotary evaporation at 55 °C, wash with ethyl acetate, and vacuum dry at 70 °C for 8 d to obtain a functionalized imidazole salt;

[0096] S2: 9 g of functionalized imidazole salt was dissolved in a container containing a mixed solution of 42 mL of ethanol and 11 mL of deionized water, and 5.87 mL of divinylbenzene was added. The temperature of the system was raised to 80 ° C under a nitrogen environment, and 0.29 g of azobisisobutyronitrile was slowly added. After reacting for 12 hours, the mixture was filtered and separated, and washed with a mixed solution of ethanol and deionized water in a volume ratio of 3:1, and dried to obtain functionalized imidazole powder;

[0097] S3: Dissolve 12 g of functionalized imidazole powder in 21 mL of 50 vt% sodium hydroxide solution, stir for 4 days, centrifuge and filter, wash, add 30 vt% acetic acid aqueous solution and stir for 3 days, filter and wash to obtain an antibacterial and antifungal agent.

[0098] The present embodiment discloses an antibacterial and mildewproof environmentally friendly water-based paint, which is composed of the following ingredients in parts by weight: 35 parts of acrylic resin, 2.5 parts of titanium dioxide, 2.6 parts of defoaming agent, 1.6 parts of leveling agent, 1.3 parts of dispersant, 1.6 parts of film-forming aid, 11 parts of composite nanofibers, 4 parts of antibacterial and mildewproof agent, and 72 parts of deionized water.

[0099] This embodiment discloses a method for preparing an antibacterial and mildew-proof environmentally friendly water-based coating, comprising the following steps:

[0100] Step (1): add acrylic resin to 52 parts of deionized water and stir for 15 minutes, then add defoamer, leveling agent, film-forming aid, and finally add titanium dioxide, stir for 45 minutes to obtain a mixed solution;

[0101] Step (2): Add composite nanofibers, antibacterial and mildew-proof agent and dispersant to 20 parts of deionized water in sequence, stir for 15 minutes, pour into the mixed solution and continue stirring for 40 minutes, let stand for 30 minutes, and obtain antibacterial and mildew-proof environmentally friendly water-based coating.

[0102] Embodiment 5: This embodiment discloses a method for preparing composite nanofibers, comprising the following steps:

[0103] Q1: Add 3.54 g of 1-vinyl-3-ethylimidazolium bromide and azobisisobutyronitrile to a container, then add 1.4 g of 3-butenenitrile, and then continue to add N,N-dimethylformamide, stir to dissolve, expel air, introduce nitrogen, heat at 80°C with magnetic stirring for 10 h, and after the reaction is completed, obtain a reaction liquid, take another clean container, pour isopropanol, and add the reaction liquid dropwise to the isopropanol under stirring. Solids are generated during the dropwise addition. After the dropwise addition is completed, filter with a vacuum pump, wash with isopropanol 3 times, and dry at 80°C for 10 h to obtain intermediate product 1;

[0104] Q2: Add 2.95 g of intermediate product 1 and 1.1 g of triethylamine to a container, then add N,N-dimethylformamide, stir to dissolve, heat to react at 75°C for 10 h, and after the reaction, precipitate the product with isopropanol, vacuum filter, wash with isopropanol 3 times, and dry at 80°C for 10 h to obtain intermediate product 2;

[0105] Q3: Dissolve 4.2 g of intermediate product 2 in 11 mL of N,N-dimethylformamide, stir and dissolve to obtain a spinning solution, use electrospinning technology to obtain nanofibers, and dry at 75°C for 24 hours to obtain composite nanofibers.

[0106] This embodiment discloses a method for preparing an antibacterial and mildew-proof agent, comprising the following steps:

[0107] S1: Add 1.2 mL of 1-allylimidazole to 2.84 mL of acetonitrile, stir, add 1.42 mL of 2-bromoethylamine hydrobromide, heat under reflux at 80 °C for 48 h after fully dissolving, and after the reaction is completed, perform rotary evaporation at 55 °C, wash with ethyl acetate, and vacuum dry at 70 °C for 8 d to obtain a functionalized imidazole salt;

[0108] S2: 11 g of functionalized imidazole salt was dissolved in a container containing a mixed solution of 33 mL of ethanol and 12 mL of deionized water, and 5.02 mL of divinylbenzene was added. The temperature of the system was raised to 80 ° C under a nitrogen environment, and 0.18 g of azobisisobutyronitrile was slowly added. After reacting for 12 hours, the mixture was filtered and separated, and washed with a mixed solution of ethanol and deionized water in a volume ratio of 3:1, and dried to obtain functionalized imidazole powder;

[0109] S3: Dissolve 16 g of functionalized imidazole powder in 22 mL of 50 vt% sodium hydroxide solution, stir for 4 days, centrifuge and filter, wash, add 30 vt% acetic acid aqueous solution and stir for 3 days, filter and wash to obtain an antibacterial and antifungal agent.

[0110] The present embodiment discloses an antibacterial and mildewproof environmentally friendly water-based paint, which is composed of the following ingredients in parts by weight: 45 parts of acrylic resin, 3.5 parts of titanium dioxide, 1.5 parts of defoaming agent, 1.4 parts of leveling agent, 1.1 parts of dispersant, 1.2 parts of film-forming aid, 9 parts of composite nanofibers, 2 parts of antibacterial and mildewproof agent, and 77 parts of deionized water.

[0111] This embodiment discloses a method for preparing an antibacterial and mildew-proof environmentally friendly water-based coating, comprising the following steps:

[0112] Step (1): add acrylic resin to 55 parts of deionized water and stir for 15 minutes, then add defoamer, leveling agent, film-forming aid, and finally add titanium dioxide, stir for 45 minutes to obtain a mixed solution;

[0113] Step (2): Add composite nanofibers, antibacterial and mildew-proof agent and dispersant to 22 parts of deionized water in sequence, stir for 15 minutes, pour into the mixed solution and continue stirring for 40 minutes, let stand for 30 minutes, and obtain an antibacterial and mildew-proof environmentally friendly water-based coating.

[0114] Comparative Example 1: Compared with Example 1, in the process of preparing the composite nanofibers in Comparative Example 1, 1-vinyl-3-ethylimidazolium bromide is not added, and other conditions remain unchanged.

[0115] Comparative Example 2: Compared with Example 1, in the process of preparing the composite nanofibers in Comparative Example 2, 3-butenenitrile is not added, and other conditions remain unchanged.

[0116] Comparative Example 3: Compared with Example 1, in Comparative Example 3, during the preparation of the composite nanofibers, no triethylamine was added, and other conditions remained unchanged.

[0117] Comparative Example 4: Compared with Example 1, in the process of preparing the antibacterial and mildew-proofing agent in Comparative Example 4, 1-allylimidazole is not added, and other conditions remain unchanged.

[0118] Comparative Example 5: Compared with Example 1, in the process of preparing the antibacterial and mildew-proofing agent in Comparative Example 5, 2-bromoethylamine hydrobromide is not added, and other conditions remain unchanged.

[0119] Comparative Example 6: Compared with Example 1, in the process of preparing the antibacterial and mildew-proofing agent in Comparative Example 6, no divinylbenzene is added, and other conditions remain unchanged.

[0120] Comparative Example 7: Compared with Example 1, in the process of preparing the antibacterial and mildew-proof environmentally friendly water-based coating in Comparative Example 7, no composite nanofibers are added, and other conditions remain unchanged.

[0121] Comparative Example 8: Compared with Example 1, in Comparative Example 8, during the process of preparing the antibacterial and mildew-proof environmentally friendly water-based coating, no antibacterial and mildew-proof agent is added, and other conditions remain unchanged.

[0122] Comparative Example 9: Compared with Example 1, in the process of preparing the antibacterial and mildew-proof environmentally friendly water-based coating in Comparative Example 9, ethanol is used instead of deionized water, and other conditions remain unchanged.

[0123] The obtained samples were subjected to performance tests, the weather resistance of the samples was tested according to ISO 11507-2007, the antibacterial performance of the samples was tested according to GB / T 21866-2008, the mildew resistance of the samples was tested according to GB / T 1741-2007, and the environmental protection performance of the samples was tested according to GB / T 18582-2020. The test results are shown in Table 1:

[0124] Table 1

[0125] project Crack situation Antibacterial rate / % Fungal growth VOC concentration / g·L Example 1 Level 1 98.45 Level 0 10.34 Example 2 Level 1 98.29 Level 0 10.61 Example 3 Level 1 98.11 Level 0 10.94 Example 4 Level 1 98.97 Level 0 10.87 Example 5 Level 1 98.07 Level 0 10.73 Comparative Example 1 Level 3 90.23 Level 2 12.15 Comparative Example 2 Level 3 90.86 Level 2 11.36 Comparative Example 3 Level 3 90.61 Level 2 12.54 Comparative Example 4 Level 2 87.73 Level 3 13.75 Comparative Example 5 Level 2 86.51 Level 3 13.96 Comparative Example 6 Level 2 85.11 Level 3 13.71 Comparative Example 7 Level 3 84.32 Level 3 13.37 Comparative Example 8 Level 2 82.26 Level 3 14.65 Comparative Example 9 Level 1 98.11 Level 0 24.64

[0126] It can be seen from the test results in Table 1 that the water-based coatings prepared in Examples 1-5 of the present invention have excellent weather resistance, antibacterial and mildew resistance, and environmental protection. Comparison between Comparative Example 1 and Examples 1-5 shows that the addition of 1-vinyl-3-ethyl imidazole bromide can effectively improve the weather resistance and antibacterial and mildew resistance of the coating; comparison between Comparative Example 2 and Examples 1-5 shows that the addition of 3-butenenitrile can effectively improve the weather resistance and antibacterial and mildew resistance of the coating; comparison between Comparative Example 3 and Examples 1-5 shows that the addition of triethylamine can effectively improve the weather resistance and antibacterial and mildew resistance of the coating; comparison between Comparative Example 4 and Examples 1-5 shows that the addition of 1-allylimidazole can effectively improve the antibacterial and mildew resistance of the coating; comparison between Comparative Example 5 and Examples 1- 5, it can be seen that the addition of 2-bromoethylamine hydrobromide can effectively improve the antibacterial and mildew-proof properties of the coating; from the comparison of comparative example 6 and examples 1-5, it can be seen that the addition of divinylbenzene can effectively improve the antibacterial and mildew-proof properties of the coating; from the comparison of comparative example 7 and examples 1-5, it can be seen that the addition of composite nanofibers can effectively improve the weather resistance and antibacterial and mildew-proof properties of the coating; from the comparison of comparative example 8 and examples 1-5, it can be seen that the addition of antibacterial and mildew-proof agents can effectively improve the antibacterial and mildew-proof properties of the coating; from the comparison of comparative example 9 and examples 1-5, it can be seen that the addition of deionized water can effectively improve the environmental performance of the coating.

[0127] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0128] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An antibacterial and mildew-proof environmentally friendly water-based paint, characterized in that: The invention is composed of the following components in parts by weight: 30-50 parts of acrylic resin, 2-4 parts of titanium dioxide, 1-3 parts of defoaming agent, 1.2-1.8 parts of leveling agent, 1-1.4 parts of dispersant, 1.1-1.7 parts of film-forming aid, 8-12 parts of composite nanofibers, 1-5 parts of antibacterial and mildew-proof agent, and 70-80 parts of deionized water, wherein the composite nanofibers are prepared from 1-vinyl-3-ethylimidazole bromide, 3-butenenitrile, triethylamine and N,N-dimethylformamide, and the antibacterial and mildew-proof agent is prepared from 1-allylimidazole, 2-bromoethylamine hydrobromide and divinylbenzene.

2. The antibacterial and mildew-proof environmentally friendly water-based paint according to claim 1, characterized in that: The method for preparing the composite nanofiber comprises the following steps: Q1: Add 1-vinyl-3-ethylimidazolium bromide and azobisisobutyronitrile to a container, then add 3-butenenitrile, and then continue to add N,N-dimethylformamide, stir to dissolve, expel air, introduce nitrogen, heat and magnetically stir, and after the reaction is completed, obtain a reaction liquid, take another clean container, pour isopropanol, and drop the reaction liquid into the isopropanol under stirring. Solids are generated during the dropwise addition. After the dropwise addition is completed, filter with a vacuum pump, wash, and dry to obtain intermediate product 1; Q2: Add the intermediate product 1 and triethylamine into a container, then add N,N-dimethylformamide, stir to dissolve, heat to react, and after the reaction is completed, precipitate the product with isopropanol, vacuum filter, wash, and dry to obtain the intermediate product 2; Q3: The intermediate product 2 is dissolved in N,N-dimethylformamide, stirred to dissolve, and a spinning solution is obtained. The nanofibers are obtained by electrospinning technology, and the composite nanofibers are obtained after constant temperature drying.

3. The antibacterial and mildew-proof environmentally friendly water-based paint according to claim 2, characterized in that: In the Q1, the molar ratio of 1-vinyl-3-ethylimidazolium bromide to 3-butenenitrile is 1:(0.8-1.2), the heating magnetic stirring temperature is 80-85°C, the time is 8-10h, it is washed with isopropanol 3-5 times, and the drying temperature is 70-80°C for 10-12h.

4. The antibacterial and mildew-proof environmentally friendly water-based paint according to claim 2, characterized in that: In the Q2, the molar ratio of the intermediate product 1 and triethylamine is (0.9-1.2): (0.8-1.2), the heating temperature is 70-75°C, the reaction time is 8-10h, and the reaction is washed with isopropanol 3-5 times. The drying temperature is 70-80°C and the reaction time is 10-12h. In the Q3, the amount ratio of the intermediate product 2 and N,N-dimethylformamide is (3-5) g: (10-16) mL, the drying temperature is 70-75°C and the reaction time is 20-24h.

5. The antibacterial and mildew-proof environmentally friendly water-based paint according to claim 1, characterized in that: The preparation method of the antibacterial and mildew-proof agent comprises the following steps: S1: adding 1-allylimidazole to acetonitrile, stirring and adding 2-bromoethylamine hydrobromide, heating under reflux for reaction after fully dissolving, and after the reaction is completed, rotary evaporation, washing, and vacuum drying are performed to obtain a functionalized imidazole salt; S2: dissolving the functionalized imidazole salt in a container containing a mixed solution of ethanol and deionized water, adding divinylbenzene, heating the system under a nitrogen environment, slowly adding azobisisobutyronitrile, and after the reaction, filtering, separating, washing, and drying to obtain a functionalized imidazole powder; S3: dissolving the functionalized imidazole powder in a sodium hydroxide solution, stirring, centrifugally filtering, washing, stirring, filtering, and washing to obtain an antibacterial and antifungal agent.

6. The antibacterial and mildew-proof environmentally friendly water-based paint according to claim 5, characterized in that: In S1, the molar ratio of 1-allylimidazole, acetonitrile and 2-bromoethylamine hydrobromide is (0.2-0.4):(1-2):(0.22-0.44), the heating reflux reaction temperature is 70-80°C, the time is 48-52h, the rotary evaporation temperature is 50-55°C, the washing is carried out with ethyl acetate, and the vacuum drying temperature is 60-70°C, and the time is 7-8d.

7. The antibacterial and mildew-proof environmentally friendly water-based paint according to claim 5, characterized in that: In the S2, the dosage ratio of the functionalized imidazole salt, ethanol, deionized water, divinylbenzene and azobisisobutyronitrile is (8-12) g: (30-45) mL: (10-15) mL: (4.9-6.13) mL: (0.13-0.35) g, the heating temperature is 80-83°C, the reaction time is 10-12 h, and the mixture is washed with a mixed solution of ethanol and deionized water in a volume ratio of 3:

1. In the S3, the dosage ratio of the functionalized imidazole powder and the sodium hydroxide solution is (10-18) g: (20-25) mL, the volume fraction of the sodium hydroxide solution is 50 vt%, the stirring time is 3-4 d, and an acetic acid aqueous solution with a volume fraction of 30 vt% is added and stirred for 2-4 d.

8. A method for preparing an antibacterial and mildew-proof environmentally friendly water-based coating according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step (1): adding acrylic resin to deionized water and stirring, then adding a defoamer, a leveling agent, and a film-forming aid, and finally adding titanium dioxide, and stirring to obtain a mixed solution; Step (2): Add the composite nanofiber, antibacterial and mildew-proof agent and dispersant to deionized water in sequence, stir thoroughly, pour the mixture into the mixed solution, continue stirring, and let stand to obtain an antibacterial and mildew-proof environmentally friendly water-based paint.

9. The method for preparing an antibacterial and mildew-proof environmentally friendly water-based coating according to claim 8, characterized in that: In the step (1), the stirring time is 10-15 min, and the stirring time is 30-45 min; in the step (2), the stirring time is 10-15 min, the continued stirring time is 30-40 min, and the standing time is 20-40 min.

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