A protective coating for buildings and its preparation method

Abstract

This invention discloses a protective coating for buildings and its preparation method, relating to the field of coatings. It comprises the following raw materials in parts by weight: 40-60 parts of an acrylate copolymer, 5-7 parts of a film-forming aid, 15-20 parts of a pigment, 10-15 parts of a filler, 0.3-0.5 parts of a wetting agent, 0.4-0.8 parts of a dispersant, 0.8-1.0 parts of a thickener, 0.2-0.6 parts of a defoamer, 0.3-0.5 parts of a leveling agent, 1.0-1.5 parts of an antioxidant, and 30-40 parts of water. The synthesized acrylate copolymer contains sodium sulfonate groups, phosphoramide structures, epoxy groups, etc., which enhance the flame retardancy and smoke suppression properties of the coating. The synthesized antioxidant contains mesoporous titanium dioxide, amino groups, hindered phenols, and sulfides, which enhance the aging resistance of the coating and synergistically improve the waterproofness of the coating with the acrylate copolymer.

Description

Technical Field

[0001] This invention relates to the field of coatings, and more specifically to a protective coating for buildings and its preparation method. Background Technology

[0002] With the advancement of science and technology and the gradual improvement of people's living standards, higher performance requirements are being placed on building protective coatings. Coatings can be divided into water-based coatings and solvent-based coatings according to the different dispersion media. Compared with solvent-based coatings, water-based coatings have characteristics such as being green, healthy, and environmentally friendly, becoming the trend and direction of the coating industry. Water-based acrylic resin coatings have excellent film properties, stain resistance, acid and alkali resistance, and do not damage the appearance of the coated object, and are widely used in the construction field. However, the flammability of acrylic coatings remains a problem that urgently needs to be solved in practical use. Building protective coatings that are exposed to harsh environments such as high light and high humidity for extended periods require better anti-aging and waterproof properties to maintain excellent performance and extend service life in harsh environments. Therefore, it is urgent to develop suitable modification methods to improve the flame retardancy, waterproofness, and aging resistance of water-based acrylic resin coatings for building protection to meet increasingly stringent usage requirements. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a building protective coating and its preparation method.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A protective coating for buildings comprises the following raw materials in parts by weight: 40-60 parts of acrylic copolymer, 5-7 parts of film-forming aid, 15-20 parts of pigment, 10-15 parts of filler, 0.3-0.5 parts of wetting agent, 0.4-0.8 parts of dispersant, 0.8-1.0 parts of thickener, 0.2-0.6 parts of defoamer, 0.3-0.5 parts of leveling agent, 1.0-1.5 parts of antioxidant, and 30-40 parts of water;

[0006] The film-forming aid is propylene glycol methyl ether acetate, the pigment is titanium dioxide, the filler is hollow glass microspheres, the wetting agent is fatty alcohol polyoxyethylene ether (supplier: Xingtai Xinlan Technology Co., Ltd.), the dispersant is sodium polyacrylate dispersant, the thickener is hydroxyethyl cellulose, the defoamer is emulsified silicone oil (supplier: Hebei Chuangzhiyuan Biotechnology Co., Ltd.), and the leveling agent is polyether-modified polysiloxane.

[0007] The preparation of the building protective coating includes the following steps:

[0008] Step S1: Place deionized water, defoamer, dispersant, and wetting agent into a dispersion tank and stir at 500-600 r / min for 10-15 min. Then add pigment and filler and continue stirring at 1200-1300 r / min for 20-25 min to obtain a mixed system.

[0009] Step S2: Adjust the rotation speed to 500-600 r / min, add acrylate copolymer, film-forming aid, thickener, defoamer, leveling agent and antioxidant to the obtained mixture, stir for 10-15 min to obtain building protective coating;

[0010] Furthermore, the weight ratio of the defoamer added in step S1 and step S2 is 1:1, and the sum of the weights of the defoamer added in step S1 and step S2 is the total amount of defoamer used.

[0011] The preparation of the acrylate copolymer includes the following steps:

[0012] Step A1: Add dimethylphosphoryl chloride to toluene, then add sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate. Stir at 0-5℃ for 2 hours, then raise the temperature to 40-50℃ and reflux for 1 hour. Filter, extract, and dry to obtain reaction product 1.

[0013] Furthermore, the ratio of dimethylphosphoryl chloride, toluene, and sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate is 0.1 mol: 100-110 mL: 0.1 mol;

[0014] In step A1, the phosphoryl chloride in dimethylphosphoryl chloride reacts with the amino group of sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate to generate reaction product 1 containing phosphoramide.

[0015] Step A2: Add reaction product 1 and ethyl acetate to a three-necked flask, heat to 45-55℃, turn on reflux and stir, then add sodium dithionite, and reflux and stir for 1-1.5h to obtain reaction product 2.

[0016] Furthermore, the ratio of reaction product 1, ethyl acetate, and sodium dithionite is 0.1 mol: 120-130 mL: 0.1-0.15 mol;

[0017] During step A2, the nitro group of reaction product 1 is reduced to an amino group to obtain reaction product 2;

[0018] Step A3: Add reaction product 2, potassium carbonate and dimethyl sulfoxide to a flask to obtain mixture a, then add methacrylamide chloride to dimethyl sulfoxide to obtain mixture b. Under an ice-water bath at 0°C, slowly add mixture b to mixture a. After the addition is complete, raise the temperature to 40°C and stir the reaction at a constant temperature for 10 hours to obtain reaction product c.

[0019] Furthermore, the ratio of reaction product 2, potassium carbonate, and dimethyl sulfoxide is 0.1 mol: 0.015 mol: 125-135 mL; the ratio of methacryloyl chloride to dimethyl sulfoxide is 0.1 mol: 25-35 mL; and the ratio of mixture a to mixture b is 130-140 mL: 30-40 mL.

[0020] In step A3, the amino group of reaction product 2 reacts with methacryloyl chloride to generate reaction product c containing a terminal double bond;

[0021] Step A4: Add glycidyl methacrylate and reaction product c to a three-necked flask, start stirring, slowly heat to 58-62℃, slowly add potassium persulfate solution to the flask within 20 min, stir and react at a constant temperature for 4-5 h, then heat to 64-66℃, continue stirring and react for 30 min, cool to room temperature to obtain acrylate copolymer.

[0022] Furthermore, the ratio of glycidyl methacrylate, reaction product c, and potassium persulfate solution is 0.17 mol: 0.20 mol: 35-40 mL, and the concentration of potassium persulfate solution is 0.014 g / mL.

[0023] During step A4, under the action of potassium persulfate, glycidyl methacrylate and reaction product c undergo free radical copolymerization to generate an acrylate copolymer.

[0024] The antioxidant is prepared by the following steps:

[0025] Step B1: Add 3,5-di-tert-butyl-4-hydroxyacetonitrile to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, introduce hydrogen gas, and stir the reaction at atmospheric pressure for 48 hours to obtain reaction product a.

[0026] Furthermore, the ratio of 3,5-di-tert-butyl-4-hydroxyacetonitrile, tetrahydrofuran, Raney nickel, and Pd / C is 0.1 mol: 70-80 mL: 0.01 mol: 0.01-0.015 mol;

[0027] In step B1, the cyano group of 3,5-di-tert-butyl-4-hydroxyacetonitrile is reduced to an amino group to obtain reaction product a;

[0028] Step B2: Add reaction product a, 4-bromo-3-nitrophenyl thiocyanate (supplier: Nanjing Shizhou Biotechnology Co., Ltd.) and methanol to a flask, add 2-dicyclohexylphospho-2'-4'-6'-triisopropylbiphenyl, tris(dibenzylideneacetone)dipalladium and potassium carbonate, reflux and stir at 80°C under nitrogen protection for 4-5 h, and dry under vacuum at 50°C to obtain reaction product b;

[0029] Furthermore, the molar ratio of reaction product a, 4-bromo-3-nitrophenyl thiocyanate, methanol, 2-dicyclohexylphospho-2'-4'-6'-triisopropylbiphenyl, tris(dibenzylacetone)dipalladium, and potassium carbonate is 0.06 mol: 0.12 mol: 90-100 mL: 0.0020 g: 0.0020 g: 0.20-0.25 mol;

[0030] In step B2, the amino group of product a undergoes a dehydrobromination coupling reaction with 4-bromo-3-nitrophenyl thiocyanate to generate product b.

[0031] Step B3: Add reaction product b to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, introduce hydrogen gas, and stir the reaction under normal pressure for 48 hours to obtain reaction product c.

[0032] Furthermore, the molar ratio of reaction product b, tetrahydrofuran, Raney nickel, and Pd / C is 0.1 mol: 110-120 mL: 0.04 mol: 0.040-0.045 mol;

[0033] In step B3, both the cyano and nitro groups of reaction product b are reduced to amino groups, yielding reaction product c.

[0034] Step B4: Add mesoporous titanium dioxide and reaction product c to ethanol, and then stir under vacuum for 6-8 hours. After the reaction is complete, centrifuge and dry to obtain the loaded product. Add the loaded product to deionized water and stir for 10-20 minutes. Add sodium hexametaphosphate, continue stirring and adjust the pH of the system to alkaline. Then stir vigorously and heat to 80°C, adjust the pH of the system to 5-6, and slowly add sodium aluminate solution. Stir for 30-40 minutes and adjust the pH to 7.0. Filter, wash with water and dry to obtain the antioxidant.

[0035] Furthermore, the ratio of mesoporous titanium dioxide, reaction product c, and ethanol is 0.5-1g:3-5g:60mL, and the volume fraction of ethanol is 95%; the ratio of the supported product, sodium hexametaphosphate, and sodium aluminate solution is 18-20g:50-60mL:15-20mL, and the concentration of sodium aluminate solution is 0.1g / mL.

[0036] In step B4, mesoporous titanium dioxide has a special mesoporous structure. The small molecule reaction product c is loaded into the mesoporous titanium dioxide to obtain the loaded product. Then, using sodium hexametaphosphate as a dispersant, hydrated alumina forms a film on the surface of the mesoporous titanium dioxide to obtain the antioxidant.

[0037] The beneficial effects of this invention are as follows: This invention discloses a protective coating for buildings and its preparation method, comprising the following raw materials: an acrylate copolymer, a film-forming aid, pigments, fillers, wetting agents, dispersants, thickeners, defoamers, leveling agents, antioxidants, and water. The synthesized acrylate copolymer includes sodium sulfonate groups, phosphoramide structures, epoxy groups, etc. in its molecule. The epoxy groups can crosslink with the active amino groups contained in the antioxidant, making the crosslinked network of the matrix denser and improving the waterproofness of the coating. The sulfur element in the sodium sulfonate group generates non-combustible gases such as sulfur dioxide during combustion, diluting the concentration of combustible gases, and is solidified in the carbon layer in the form of sodium sulfate and sodium sulfite compounds, forming a dense and thick protective carbon layer, reducing heat transfer at the combustion site, effectively preventing further combustion of the matrix, and inhibiting the release of smoke. The phosphoramide structure has a synergistic flame retardant effect produced by the formation of a dense carbon layer in the solid phase and the generation of nitrogen-containing non-combustible gases in the gas phase by phosphorus and nitrogen-based flame retardants. In the solid phase, the phosphoramide structure and sodium sulfonate group make the carbon layer more dense, also producing a synergistic flame retardant effect. Compared with halogenated flame retardants, the phosphoramide structure and sodium sulfonate group overcome the problems of high toxicity and large smoke after combustion during the flame retardant process, and can effectively improve the flame retardant and smoke-suppressing performance of the coating.

[0038] The synthesized antioxidant is obtained by loading small molecule reaction product c onto mesoporous titanium dioxide, followed by coating the surface of the mesoporous titanium dioxide with hydrated alumina. Reaction product c contains active amino groups, thioether groups, and hindered phenolic structures. Mesoporous titanium dioxide possesses strong UV shielding properties. Coating its surface with inert hydrated alumina inhibits the photocatalytic activity of the mesoporous titanium dioxide, suppressing the photocatalytic degradation of the substrate by nano-titanium dioxide, preventing yellowing, chalking, or even peeling of the coating, and allowing the mesoporous titanium dioxide to better perform its UV shielding function. The active amino groups in reaction product c can crosslink with the epoxy groups in acrylate copolymers, making the crosslinked network of the substrate denser and synergistically improving the waterproofness of the coating. The hindered phenolic structures can capture free radicals generated by the polymer's thermo-oxidative aging reaction, generating hydroperoxides and relatively stable phenoxy radicals, thereby terminating the polymer's thermo-oxidative aging reaction and inhibiting chain growth. The thioether groups can reduce and decompose hydroperoxides. The synergistic effect of mesoporous titanium dioxide, hindered phenolic structures, and thioether groups gives the coating excellent aging resistance. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] An acrylate copolymer is prepared by the following steps:

[0042] Step A1: Dimethylphosphoryl chloride was added to toluene, followed by sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate. The mixture was stirred at 0°C for 2 hours, then heated to 40°C and refluxed for 1 hour. The mixture was then filtered, extracted, and dried to obtain reaction product 1. The ratio of dimethylphosphoryl chloride, toluene, and sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate was 0.1 mol: 100 mL: 0.1 mol.

[0043] Step A2: Add reaction product 1 and ethyl acetate to a three-necked flask, heat to 45°C, turn on reflux and stir, then add sodium dithionite, and reflux and stir for 1 hour to obtain reaction product 2; the ratio of reaction product 1, ethyl acetate and sodium dithionite is 0.1 mol: 120 mL: 0.1 mol.

[0044] Step A3: Add reaction product 2, potassium carbonate, and dimethyl sulfoxide to a flask to obtain mixture a. Then add methacrylamide chloride to dimethyl sulfoxide to obtain mixture b. Slowly add mixture b dropwise to mixture a under an ice-water bath at 0°C. After the addition is complete, raise the temperature to 40°C and stir the reaction at a constant temperature for 10 hours to obtain reaction product c. The ratio of reaction product 2, potassium carbonate, and dimethyl sulfoxide is 0.1 mol: 0.015 mol: 125 mL; the ratio of methacrylamide chloride to dimethyl sulfoxide is 0.1 mol: 25 mL; and the ratio of mixture a to mixture b is 130 mL: 30 mL.

[0045] Step A4: Add glycidyl methacrylate and reaction product c to a three-necked flask, start stirring, slowly heat to 58°C, slowly add potassium persulfate solution to the flask over 20 min, stir at a constant temperature for 4 h, then heat to 64°C, continue stirring for 30 min, and cool to room temperature to obtain the acrylate copolymer; the ratio of glycidyl methacrylate, reaction product c, and potassium persulfate solution is 0.17 mol: 0.20 mol: 35 mL, and the concentration of potassium persulfate solution is 0.014 g / mL.

[0046] Example 2

[0047] An acrylate copolymer is prepared by the following steps:

[0048] Step A1: Dimethylphosphoryl chloride was added to toluene, followed by sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate. The mixture was stirred at 0°C for 2 hours, then heated to 45°C and refluxed for 1 hour. The mixture was then filtered, extracted, and dried to obtain reaction product 1. The molar ratio of dimethylphosphoryl chloride, toluene, and sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate was 0.1 mol: 105 mL: 0.1 mol.

[0049] Step A2: Add reaction product 1 and ethyl acetate to a three-necked flask, heat to 50°C, turn on reflux and stir, then add sodium dithionite, and reflux and stir for 1.3 h to obtain reaction product 2; the ratio of reaction product 1, ethyl acetate and sodium dithionite is 0.1 mol: 125 mL: 0.13 mol.

[0050] Step A3: Add reaction product 2, potassium carbonate, and dimethyl sulfoxide to a flask to obtain mixture a. Then add methacrylamide chloride to dimethyl sulfoxide to obtain mixture b. Under an ice-water bath at 0°C, slowly add mixture b dropwise to mixture a. After the addition is complete, raise the temperature to 40°C and stir the reaction at a constant temperature for 10 hours to obtain reaction product c. The ratio of reaction product 2, potassium carbonate, and dimethyl sulfoxide is 0.1 mol: 0.015 mol: 130 mL; the ratio of methacrylamide chloride to dimethyl sulfoxide is 0.1 mol: 30 mL; and the ratio of mixture a to mixture b is 135 mL: 35 mL.

[0051] Step A4: Add glycidyl methacrylate and reaction product c to a three-necked flask, start stirring, slowly heat to 60°C, slowly add potassium persulfate solution to the flask over 20 min, stir at a constant temperature for 4.5 h, then heat to 65°C, continue stirring for 30 min, and cool to room temperature to obtain the acrylate copolymer; the ratio of glycidyl methacrylate, reaction product c, and potassium persulfate solution is 0.17 mol: 0.20 mol: 37 mL, and the concentration of potassium persulfate solution is 0.014 g / mL.

[0052] Example 3

[0053] An acrylate copolymer is prepared by the following steps:

[0054] Step A1: Dimethylphosphoryl chloride was added to toluene, followed by sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate. The mixture was stirred at 5°C for 2 hours, then heated to 50°C and refluxed for 1 hour. The mixture was then filtered, extracted, and dried to obtain reaction product 1. The molar ratio of dimethylphosphoryl chloride, toluene, and sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate was 0.1 mol: 110 mL: 0.1 mol.

[0055] Step A2: Add reaction product 1 and ethyl acetate to a three-necked flask, heat to 55°C, turn on reflux and stir, then add sodium dithionite, and reflux and stir for 1.5 h to obtain reaction product 2; the ratio of reaction product 1, ethyl acetate and sodium dithionite is 0.1 mol: 130 mL: 0.15 mol.

[0056] Step A3: Add reaction product 2, potassium carbonate, and dimethyl sulfoxide to a flask to obtain mixture a. Then add methacrylamide chloride to dimethyl sulfoxide to obtain mixture b. Under an ice-water bath at 0°C, slowly add mixture b dropwise to mixture a. After the addition is complete, raise the temperature to 40°C and stir the reaction at a constant temperature for 10 hours to obtain reaction product c. The ratio of reaction product 2, potassium carbonate, and dimethyl sulfoxide is 0.1 mol: 0.015 mol: 135 mL; the ratio of methacrylamide chloride to dimethyl sulfoxide is 0.1 mol: 35 mL; and the ratio of mixture a to mixture b is 140 mL: 40 mL.

[0057] Step A4: Add glycidyl methacrylate and reaction product c to a three-necked flask, start stirring, slowly heat to 62°C, slowly add potassium persulfate solution to the flask over 20 min, stir at a constant temperature for 5 h, then heat to 66°C, continue stirring for 30 min, and cool to room temperature to obtain the acrylate copolymer; the ratio of glycidyl methacrylate, reaction product c, and potassium persulfate solution is 0.17 mol: 0.20 mol: 40 mL, and the concentration of potassium persulfate solution is 0.014 g / mL.

[0058] Example 4

[0059] An anti-aging agent, the preparation of which includes the following steps:

[0060] Step B1: Add 3,5-di-tert-butyl-4-hydroxyacetonitrile to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, purge with hydrogen gas, and stir the reaction at atmospheric pressure for 48 h to obtain reaction product a; the molar ratio of 3,5-di-tert-butyl-4-hydroxyacetonitrile, tetrahydrofuran, Raney nickel and Pd / C is 0.1 mol: 70 mL: 0.01 mol: 0.01 mol;

[0061] Step B2: Add reaction product a, 4-bromo-3-nitrophenyl thiocyanate (supplier: Nanjing Shizhou Biotechnology Co., Ltd.), and methanol to a flask, add 2-dicyclohexylphospho-2'-4'-6'-triisopropylbiphenyl, tris(dibenzylideneacetone)dipalladium, and potassium carbonate, and reflux and stir at 80°C under nitrogen protection for 4 hours. Dry under vacuum at 50°C to obtain reaction product b. The molar ratio of reaction product a, 4-bromo-3-nitrophenyl thiocyanate, methanol, 2-dicyclohexylphospho-2'-4'-6'-triisopropylbiphenyl, tris(dibenzylideneacetone)dipalladium, and potassium carbonate is 0.06mol:0.12mol:90mL:0.0020g:0.0020g:0.20mol.

[0062] Step B3: Add reaction product b to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, introduce hydrogen gas, and stir the reaction under normal pressure for 48 hours to obtain reaction product c; the ratio of reaction product b, tetrahydrofuran, Raney nickel and Pd / C is 0.1 mol: 110 mL: 0.04 mol: 0.040 mol.

[0063] Step B4: Add mesoporous titanium dioxide and reaction product c to ethanol, then stir under vacuum for 6 hours. After the reaction is complete, centrifuge and dry to obtain the loaded product. Add the loaded product to deionized water, stir for 10 minutes, add sodium hexametaphosphate, continue stirring and adjust the pH of the system to alkaline, then stir vigorously and heat to 80℃, adjust the pH of the system to 5, then slowly add sodium aluminate solution, stir for 30 minutes, adjust the pH to 7.0, filter, wash with water, and dry to obtain the antioxidant. The volume ratio of mesoporous titanium dioxide, reaction product c, and ethanol is 0.5g:3g:60mL, and the volume fraction of ethanol is 95%. The volume ratio of the loaded product, sodium hexametaphosphate, and sodium aluminate solution is 18g:50mL:15mL, and the concentration of sodium aluminate solution is 0.1g / mL.

[0064] Example 5

[0065] An anti-aging agent, the preparation of which includes the following steps:

[0066] Step B1: Add 3,5-di-tert-butyl-4-hydroxyacetonitrile to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, purge with hydrogen gas, and stir the reaction at atmospheric pressure for 48 h to obtain reaction product a; the ratio of 3,5-di-tert-butyl-4-hydroxyacetonitrile, tetrahydrofuran, Raney nickel and Pd / C is 0.1 mol: 75 mL: 0.01 mol: 0.013 mol;

[0067] Step B2: Add reaction product a, 4-bromo-3-nitrophenyl thiocyanate (supplier: Nanjing Shizhou Biotechnology Co., Ltd.), and methanol to a flask, add 2-dicyclohexylphosphine-2'-4'-6'-triisopropylbiphenyl, tris(dibenzylideneacetone)dipalladium, and potassium carbonate, and reflux and stir at 80°C under nitrogen protection for 4.5 h. Dry under vacuum at 50°C to obtain reaction product b. The molar ratio of reaction product a, 4-bromo-3-nitrophenyl thiocyanate, methanol, 2-dicyclohexylphosphine-2'-4'-6'-triisopropylbiphenyl, tris(dibenzylideneacetone)dipalladium, and potassium carbonate is 0.06 mol: 0.12 mol: 95 mL: 0.0020 g: 0.0020 g: 0.23 mol.

[0068] Step B3: Add reaction product b to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, introduce hydrogen gas, and stir the reaction under normal pressure for 48 hours to obtain reaction product c; the ratio of reaction product b, tetrahydrofuran, Raney nickel and Pd / C is 0.1 mol: 115 mL: 0.04 mol: 0.043 mol.

[0069] Step B4: Add mesoporous titanium dioxide and reaction product c to ethanol, and stir under vacuum for 7 hours. After the reaction is complete, centrifuge and dry to obtain the loaded product. Add the loaded product to deionized water, stir for 15 minutes, add sodium hexametaphosphate, continue stirring and adjust the pH of the system to alkaline, then stir vigorously and heat to 80°C, adjust the pH of the system to 5, then slowly add sodium aluminate solution, stir for 35 minutes, adjust the pH to 7.0, filter, wash with water, and dry to obtain the antioxidant. The volume ratio of mesoporous titanium dioxide, reaction product c, and ethanol is 0.7 g: 4 g: 60 mL, and the volume fraction of ethanol is 95%. The volume ratio of the loaded product, sodium hexametaphosphate, and sodium aluminate solution is 19 g: 55 mL: 17 mL, and the concentration of sodium aluminate solution is 0.1 g / mL.

[0070] Example 6

[0071] An anti-aging agent, the preparation of which includes the following steps:

[0072] Step B1: Add 3,5-di-tert-butyl-4-hydroxyacetonitrile to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, purge with hydrogen gas, and stir the reaction at atmospheric pressure for 48 h to obtain reaction product a; the molar ratio of 3,5-di-tert-butyl-4-hydroxyacetonitrile, tetrahydrofuran, Raney nickel and Pd / C is 0.1 mol: 80 mL: 0.01 mol: 0.015 mol;

[0073] Step B2: Add reaction product a, 4-bromo-3-nitrophenyl thiocyanate (supplier: Nanjing Shizhou Biotechnology Co., Ltd.), and methanol to a flask, add 2-dicyclohexylphosphine-2'-4'-6'-triisopropylbiphenyl, tris(dibenzylideneacetone)dipalladium, and potassium carbonate, and reflux and stir at 80°C under nitrogen protection for 5 hours. Dry under vacuum at 50°C to obtain reaction product b. The molar ratio of reaction product a, 4-bromo-3-nitrophenyl thiocyanate, methanol, 2-dicyclohexylphosphine-2'-4'-6'-triisopropylbiphenyl, tris(dibenzylideneacetone)dipalladium, and potassium carbonate is 0.06mol:0.12mol:100mL:0.0020g:0.0020g:0.25mol.

[0074] Step B3: Add reaction product b to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, introduce hydrogen gas, and stir the reaction under normal pressure for 48 hours to obtain reaction product c; the ratio of reaction product b, tetrahydrofuran, Raney nickel and Pd / C is 0.1mol:120mL:0.04mol:0.045mol.

[0075] Step B4: Add mesoporous titanium dioxide and reaction product c to ethanol, and stir under vacuum for 8 hours. After the reaction is complete, centrifuge and dry to obtain the loaded product. Add the loaded product to deionized water, stir for 20 minutes, add sodium hexametaphosphate, continue stirring and adjust the pH of the system to alkaline, then stir vigorously and heat to 80°C, adjust the pH of the system to 6, then slowly add sodium aluminate solution, stir for 40 minutes, adjust the pH to 7.0, filter, wash with water, and dry to obtain the antioxidant. The volume ratio of mesoporous titanium dioxide, reaction product c, and ethanol is 1 g: 5 g: 60 mL, and the volume fraction of ethanol is 95%. The volume ratio of the loaded product, sodium hexametaphosphate, and sodium aluminate solution is 20 g: 60 mL: 20 mL, and the concentration of sodium aluminate solution is 0.1 g / mL.

[0076] Example 7

[0077] A building protective coating comprises the following raw materials in parts by weight: 40 parts of acrylate copolymer, 5 parts of film-forming aid, 15 parts of pigment, 10 parts of filler, 0.3 parts of wetting agent, 0.4 parts of dispersant, 0.8 parts of thickener, 0.2 parts of defoamer, 0.3 parts of leveling agent, 1.0 part of antioxidant, and 30 parts of water; wherein the film-forming aid is propylene glycol methyl ether acetate, the pigment is titanium dioxide, the filler is hollow glass microspheres, the wetting agent is fatty alcohol polyoxyethylene ether (supplier: Xingtai Xinlan Technology Co., Ltd.), the dispersant is sodium polyacrylate dispersant, the thickener is hydroxyethyl cellulose, the defoamer is emulsified silicone oil (supplier: Hebei Chuangzhiyuan Biotechnology Co., Ltd.), and the leveling agent is polyether-modified polysiloxane;

[0078] The preparation of the building protective coating includes the following steps:

[0079] Step S1: Place deionized water, defoamer, dispersant, and wetting agent into a dispersion tank and stir at 500 r / min for 10 min. Then add pigment and filler and continue stirring at 1200 r / min for 20 min to obtain a mixed system.

[0080] Step S2: Adjust the rotation speed to 500 r / min, add the acrylate copolymer obtained in Example 1, film-forming aid, thickener, defoamer, leveling agent, and antioxidant obtained in Example 4 to the resulting mixture, stir for 10 min, and obtain the coating for building protection; the weight ratio of the defoamer added in Step S1 and Step S2 is 1:1, and the sum of the weights of the defoamer added in Step S1 and Step S2 is the total amount of defoamer used.

[0081] Example 8

[0082] A building protective coating comprises the following raw materials in parts by weight: 50 parts of acrylate copolymer, 6 parts of film-forming aid, 17 parts of pigment, 13 parts of filler, 0.4 parts of wetting agent, 0.6 parts of dispersant, 0.9 parts of thickener, 0.4 parts of defoamer, 0.4 parts of leveling agent, 1.3 parts of antioxidant, and 35 parts of water; wherein the film-forming aid is propylene glycol methyl ether acetate, the pigment is titanium dioxide, the filler is hollow glass microspheres, the wetting agent is fatty alcohol polyoxyethylene ether (supplier: Xingtai Xinlan Technology Co., Ltd.), the dispersant is sodium polyacrylate dispersant, the thickener is hydroxyethyl cellulose, the defoamer is emulsified silicone oil (supplier: Hebei Chuangzhiyuan Biotechnology Co., Ltd.), and the leveling agent is polyether-modified polysiloxane;

[0083] The preparation of the building protective coating includes the following steps:

[0084] Step S1: Place deionized water, defoamer, dispersant, and wetting agent into a dispersion tank and stir at 550 r / min for 13 min. Then add pigment and filler and continue stirring at 1250 r / min for 23 min to obtain a mixed system.

[0085] Step S2: Adjust the rotation speed to 550 r / min, add the acrylate copolymer obtained in Example 2, film-forming aid, thickener, defoamer, leveling agent, and antioxidant obtained in Example 5 to the resulting mixture, stir for 12 min to obtain a building protective coating; the weight ratio of the defoamer added in Step S1 and Step S2 is 1:1, and the sum of the weights of the defoamer added in Step S1 and Step S2 is the total amount of defoamer used.

[0086] Example 9

[0087] A building protective coating comprises the following raw materials in parts by weight: 60 parts of acrylate copolymer, 7 parts of film-forming aid, 20 parts of pigment, 15 parts of filler, 0.5 parts of wetting agent, 0.8 parts of dispersant, 1.0 part of thickener, 0.6 parts of defoamer, 0.5 parts of leveling agent, 1.5 parts of antioxidant, and 40 parts of water; wherein the film-forming aid is propylene glycol methyl ether acetate, the pigment is titanium dioxide, the filler is hollow glass microspheres, the wetting agent is fatty alcohol polyoxyethylene ether (supplier: Xingtai Xinlan Technology Co., Ltd.), the dispersant is sodium polyacrylate dispersant, the thickener is hydroxyethyl cellulose, the defoamer is emulsified silicone oil (supplier: Hebei Chuangzhiyuan Biotechnology Co., Ltd.), and the leveling agent is polyether-modified polysiloxane;

[0088] The preparation of the building protective coating includes the following steps:

[0089] Step S1: Place deionized water, defoamer, dispersant, and wetting agent into a dispersion tank and stir at 600 r / min for 15 min. Then add pigment and filler and continue stirring at 1300 r / min for 25 min to obtain a mixed system.

[0090] Step S2: Adjust the rotation speed to 600 r / min, add the acrylate copolymer obtained in Example 3, film-forming aid, thickener, defoamer, leveling agent, and antioxidant obtained in Example 6 to the resulting mixture, stir for 15 min, and obtain the coating for building protection; the weight ratio of the defoamer added in Step S1 and Step S2 is 1:1, and the sum of the weights of the defoamer added in Step S1 and Step S2 is the total amount of defoamer used.

[0091] Comparative Example 1

[0092] This comparative example is a commercially available building protective polyacrylate coating.

[0093] Comparative Example 2

[0094] Compared with Example 9, the acrylic copolymer was replaced with polyglycidyl methacrylate, and the rest was exactly the same as in Example 9, to obtain a building protective coating.

[0095] Comparative Example 3

[0096] Compared with Example 9, the antioxidant was replaced with the loaded product in Example 6, and everything else was exactly the same as in Example 9, to obtain a building protective coating.

[0097] The following is a further performance test of the building protective coating prepared according to the present invention, and the test results are as follows.

[0098] To test the building protective coating prepared in this invention, the water resistance of the coating was determined according to GB / T1733-1993 "Determination of Water Resistance of Paint Film"; the flame retardancy time was determined according to GB12441-2018 "Fire-retardant Coatings for Finishing"; and the total smoke emission was determined using a cone calorimeter. Artificial aging tests were conducted according to GB / T1865-2009 "Artificial Climate Aging and Artificial Radiation Exposure to Filtered Xenon Arc Radiation of Paints and Varnishes". The phenomena were recorded, and the results are shown in Table 1.

[0099] Table 1: Test Results

[0100]

[0101]

[0102] Based on the data in Table 1, comparisons of Examples 7, 8, and 9 with Comparative Example 1 show that the building protective coating prepared in this invention exhibits better waterproofing, aging resistance, and flame retardant and smoke-suppressing properties compared to commercially available building protective polyacrylate coatings. Comparison of Example 9 with Comparative Example 2 shows that the introduction of sodium sulfonate and phosphoramide structures significantly improves the flame retardant and smoke-suppressing properties of the coating. Comparison of Example 9 with Comparative Example 3 shows that after loading small-molecule mesoporous titanium dioxide with a hydrated alumina coating, the mesoporous titanium dioxide can better exert its ultraviolet shielding effect and synergistically improve the aging resistance of the coating with sulfide and hindered phenol.

[0103] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A protective coating for buildings, characterized in that: The raw materials include the following parts by weight: 40-60 parts of acrylate copolymer, 5-7 parts of film-forming aid, 15-20 parts of pigment, 10-15 parts of filler, 0.3-0.5 parts of wetting agent, 0.4-0.8 parts of dispersant, 0.8-1.0 parts of thickener, 0.2-0.6 parts of defoamer, 0.3-0.5 parts of leveling agent, 1.0-1.5 parts of antioxidant, and 30-40 parts of water; The preparation of the acrylate copolymer includes the following steps: Step A1: Add dimethylphosphoryl chloride to toluene, then add sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate. Stir at 0-5℃ for 2 hours, then raise the temperature to 40-50℃ and reflux for 1 hour. Filter, extract, and dry to obtain reaction product 1. Step A2: Add reaction product 1 and ethyl acetate to a three-necked flask, heat to 45-55℃, turn on reflux and stir, then add sodium dithionite, and reflux and stir for 1-1.5h to obtain reaction product 2. Step A3: Add reaction product 2, potassium carbonate and dimethyl sulfoxide to a flask to obtain mixture a, then add methacrylamide chloride to dimethyl sulfoxide to obtain mixture b. Under an ice-water bath at 0°C, slowly add mixture b to mixture a. After the addition is complete, raise the temperature to 40°C and stir the reaction at a constant temperature for 10 hours to obtain reaction product c. Step A4: Add glycidyl methacrylate and reaction product c to a three-necked flask, start stirring, slowly heat to 58-62℃, slowly add potassium persulfate solution to the flask within 20 min, stir and react at a constant temperature for 4-5 h, then heat to 64-66℃, continue stirring and react for 30 min, cool to room temperature to obtain acrylate copolymer. The antioxidant is prepared by the following steps: Step B1: Add 3,5-di-tert-butyl-4-hydroxyacetonitrile to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, introduce hydrogen gas, and stir the reaction at atmospheric pressure for 48 hours to obtain reaction product a. Step B2: Add reaction product a, 4-bromo-3-nitrophenyl thiocyanate and methanol to a flask, add 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl, tris(dibenzylacetone)dipalladium and potassium carbonate, reflux and stir at 80°C under nitrogen protection for 4-5 h, and dry under vacuum at 50°C to obtain reaction product b; Step B3: Add reaction product b to tetrahydrofuran, start stirring, add Raney nickel and Pd / C, introduce hydrogen gas, and stir the reaction under normal pressure for 48 hours to obtain reaction product c. Step B4: Add mesoporous titanium dioxide and reaction product c to ethanol, and then stir under vacuum for 6-8 hours. After the reaction is complete, centrifuge and dry to obtain the loaded product. Add the loaded product to deionized water and stir for 10-20 minutes. Add sodium hexametaphosphate, continue stirring and adjust the pH of the system to alkaline. Then stir vigorously and heat to 80°C, adjust the pH of the system to 5-6, and slowly add sodium aluminate solution. Stir for 30-40 minutes and adjust the pH to 7.

0. Filter, wash with water and dry to obtain the antioxidant.

2. The building protective coating according to claim 1, characterized in that: In step A1, the ratio of dimethylphosphoryl chloride, toluene, and sodium 5-amino-4-methoxy-2-nitrobenzenesulfonate is 0.1 mol: 100-110 mL: 0.1 mol; in step A2, the ratio of reaction product 1, ethyl acetate, and sodium dithionite is 0.1 mol: 120-130 mL: 0.1-0.15 mol.

3. The building protective coating according to claim 1, characterized in that: In step A3, the ratio of reaction product 2, potassium carbonate, and dimethyl sulfoxide is 0.1 mol: 0.015 mol: 125-135 mL; the ratio of methacryloyl chloride to dimethyl sulfoxide is 0.1 mol: 25-35 mL; the ratio of mixture a to mixture b is 130-140 mL: 30-40 mL; in step A4, the ratio of glycidyl methacrylate, reaction product c, and potassium persulfate solution is 0.17 mol: 0.20 mol: 35-40 mL, and the concentration of potassium persulfate solution is 0.014 g / mL.

4. The building protective coating according to claim 1, characterized in that: In step B1, the ratio of 3,5-di-tert-butyl-4-hydroxyacetonitrile, tetrahydrofuran, Raney nickel, and Pd / C is 0.1 mol: 70-80 mL. 0.01 mol: 0.01-0.015 mol.

5. The building protective coating according to claim 1, characterized in that: In step B2, the ratio of reaction product a, 4-bromo-3-nitrophenyl thiocyanate, methanol, 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl, tris(dibenzylacetone)dipalladium, and potassium carbonate is 0.06 mol: 0.12 mol: 90-100 mL: 0.0020 g: 0.0020 g: 0.20-0.25 mol.

6. The building protective coating according to claim 1, characterized in that: In step B3, the ratio of reaction product b, tetrahydrofuran, Raney nickel, and Pd / C is 0.1 mol: 110-120 mL: 0.04 mol: 0.040-0.045 mol; in step B4, the ratio of mesoporous titanium dioxide, reaction product c, and ethanol is 0.5-1 g: 3-5 g: 60 mL, with an ethanol volume fraction of 95%; the ratio of the supported product, sodium hexametaphosphate, and sodium aluminate solution is 18-20 g: 50-60 mL: 15-20 mL, with a sodium aluminate solution concentration of 0.1 g / mL.

7. The building protective coating according to claim 1, characterized in that: The film-forming aid is propylene glycol methyl ether acetate, the pigment is titanium dioxide, the filler is hollow glass microspheres, the wetting agent is fatty alcohol polyoxyethylene ether, the dispersant is sodium polyacrylate dispersant, the thickener is hydroxyethyl cellulose, the defoamer is emulsified silicone oil, and the leveling agent is polyether-modified polysiloxane.

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