Antibacterial, anti-fouling and flame-retardant water-based paint for building external wall

Abstract

The invention relates to the technical field of building coatings, in particular to an antibacterial, anti-fouling and flame-retardant water-based coating for a building outer wall. The solvent type building coating for the exterior wall is not environment-friendly and relatively single in function. Aiming at the technical problems, the invention provides the antibacterial, anti-fouling and flame-retardant water-based paint for the building external wall, and the defects that the traditional paint is single in performance, poor in durability and insufficient in environmental protection property are overcome through the molecular design of the multifunctional emulsion and the synergistic interaction of functional components; flame-retardant, anti-fouling and antibacterial structural functional units are introduced into the multifunctional modified acrylate emulsion at the same time, and the structural functional units cooperate and interact with one another, so that a molecular-level coating hierarchical structure of a flame-retardant core (HEMAP)-an anti-fouling layer (fluorosilicone)-an antibacterial shell is constructed; through interaction with other functional additives such as ADP, a photocatalyst and the like in a coating formula, the coating is endowed with relatively good comprehensive properties such as flame retardance, antibacterial property and pollution resistance.

Description

Technical Field

[0001] The invention relates to the technical field of building coatings, and in particular to an antibacterial, antifouling and flame-retardant water-based coating for building exterior walls. Background Art

[0002] As a key material for building protection and decoration, exterior wall coatings must be weather-resistant, aesthetically pleasing, and functional. As people's requirements for environmental health and building safety increase, the shortcomings of traditional exterior wall coatings in terms of antibacterial, anti-fouling, and flame retardant properties are becoming increasingly prominent: Insufficient antibacterial properties: Conventional inorganic antibacterial agents (such as silver ion carriers) are easily dissolved and become ineffective, and lack photocatalytic self-cleaning capabilities, making it difficult to inhibit the long-term growth of mold; organic quaternary ammonium salt antibacterial agents have the problems of strong migration and poor durability.

[0003] Single anti-fouling mechanism: Although mainstream fluorocarbon or silicone hydrophobic agents can reduce surface energy, they are prone to molecular chain breakage under long-term ultraviolet radiation, resulting in a decline in hydrophobicity and an inability to decompose attached organic pollutants (such as oil and bioslime).

[0004] Poor synergy between flame retardancy and functionality: Additive flame retardants (such as aluminum hydroxide) require high filling amounts (>20%) to meet the standards, which seriously damages the mechanical properties of the paint film; while reactive phosphorus-based flame retardant monomers (such as HEMA phosphate) are prone to gelation during emulsion polymerization and have poor compatibility with antibacterial / antifouling components, leading to functional phase separation.

[0005] Environmental bottleneck: Solvent-based coatings are becoming more water-based due to VOC emission restrictions. However, the minimum film-forming temperature (MFFT) of existing water-based acrylic emulsions is relatively high (>10°C), and low-temperature construction requires the use of highly volatile film-forming additives (such as glycol ethers), which causes secondary pollution. Summary of the Invention

[0006] Problems with the existing technology include: solvent-based exterior wall architectural coatings are not environmentally friendly and have relatively limited functions. To address the above technical problems, the present invention provides an antibacterial, antifouling, and flame-retardant water-based coating for building exterior walls, comprising the following raw materials, calculated by weight percentage: Multifunctional modified acrylic emulsion 30-45%; Fluorosilicone modified hydrophobic agent 1-3%; Photocatalytic antibacterial agent 2-5%; Filler 3-8%; Dispersant 0.5-1.5%; Wetting agent 0.5-1.5%; Thickener 0.2-0.8%; Environmentally friendly film-forming agent 1-2%; Water balance.

[0007] Preferably, the multifunctional modified acrylic ester emulsion is prepared by including the following raw materials in parts by weight: Hydroxyethyl methacrylate phosphate (HEMAP) 95-100 parts; Butyl acrylate (BA) 390-400 parts; Methyl methacrylate (MMA) 310-320 parts; Acrylic acid (AA) 18-20 parts; Dodecafluoroheptyl methacrylate (DFMA) 76-80 parts; γ-Methacryloxypropyltrimethoxysilane (KH-570) 38-40 parts; 25-30 parts of antibacterial monomer; 12-15 parts of emulsifier; 6-8 parts of initiator; 3-4 parts sodium bicarbonate; 13-15 parts of diethylaluminum hypophosphite (ADP); 2400-2500 parts of deionized water; The antibacterial monomer is composed of methacryloyloxyethyl dimethyl hexadecyl ammonium bromide (DMAE-HB) and (acryloyloxyethyl) guanidine hydrochloride in a mass ratio of 2-3:1.

[0008] Preferably, the preparation method of the multifunctional modified acrylate emulsion comprises the following steps, in parts by weight: (1) Preparation of pre-emulsion At room temperature, the formulated amount of HEMAP, 3 / 8 of the formulated amount of BA, 5 / 16 of the formulated amount of MMA, 1 / 3 of the formulated amount of emulsifier, and 15 / 122 of the formulated amount of water were uniformly mixed, and triethylamine was added dropwise while stirring to adjust the pH of the reaction system to 6-7 to obtain a homogeneous emulsification to form a pre-emulsion; (2) Add 30 / 61 of water and 1 / 5 of emulsifier to the reactor, stir and heat to 82±0.5°C under nitrogen protection, add initiator solution I to the reaction system, stir evenly, and then add 10% of the total mass of pre-emulsion to the reaction system while stirring, keep warm and stir for at least 30 minutes to obtain seed emulsion; (3) The remaining amount of BA, the remaining amount of MMA, the remaining amount of DFMA, the remaining amount of KH-570, the remaining amount of AA, the remaining amount of emulsifier, and 35 / 122 of water are stirred and mixed to obtain a fluorine-modified emulsion; (4) Lowering the temperature of the seed emulsion to 80±1°C, adding the initiator solution II and the fluorine-modified emulsion dropwise to the seed emulsion obtained in step (3) while stirring, and completing the addition within 4 hours to obtain a fluorine-modified polymer emulsion; (5) Lower the temperature of the fluorine-modified polymer emulsion to 60±1°C, add the antibacterial monomer solution dropwise while stirring, and complete the addition within 40 minutes. Add the initiator solution III while stirring, and keep the reaction at 60°C for at least 1 hour. Then lower the temperature of the reaction system to 40°C, add the formulated amount of ADP, stir evenly, adjust the pH of the reaction system to 8.0, filter the material, and obtain a multifunctional modified acrylate emulsion; The initiator solution I is a mixture of 6 / 17 of APS and 5 / 244 of water, the initiator solution II is a mixture of 10 / 17 of APS and 3 / 61 of water, the quaternary ammonium salt solution is a mixture of the antibacterial monomer and 1 / 50 of water, and the initiator solution III is a mixture of the remaining amount of APS and the remaining amount of water.

[0009] Preferably, the fluorosilicone modified hydrophobic agent is HY-4100 lotus leaf fluorosilicone hydrophobic agent or high permeability silicone waterproofing agent SH-F23 (Guangzhou Xinxi Metallurgical Chemical Co., Ltd.).

[0010] Preferably, the photocatalytic antibacterial agent is a nano-silicon dioxide-loaded silver antibacterial agent.

[0011] Preferably, the nano-silicon dioxide silver-loaded antibacterial agent includes Jingrui New Materials VK-T07 or Hangzhou Jiuli JL-TAg10.

[0012] Preferably, the average particle size of the filler is 10-20 μm, and the filler includes one or more of calcined kaolin, wollastonite and ground calcium carbonate.

[0013] Preferably, the dispersant comprises a nonionic dispersant or an anionic sodium salt dispersant.

[0014] Preferably, the wetting agent is non-ionic wetting agent HYDRAPOL RP50 or non-ionic wetting agent Dynol360.

[0015] Preferably, the thickener is a nonionic associative thickener, for example, Rohm and Haas RM-8W.

[0016] Preferably, the environmentally friendly film-forming aid is alcohol ester twelve.

[0017] Beneficial effects: The antibacterial, antifouling, and flame-retardant water-based coating for building exterior walls provided by the present invention overcomes the shortcomings of traditional coatings such as single performance, poor durability, and insufficient environmental protection through the synergistic effect of multifunctional emulsion molecular design and functional components. The specific advantages are as follows: (1) The antibacterial, antifouling, and flame-retardant water-based coating for building exterior walls obtained by the present invention has a long-lasting synergistic effect of triple functions of flame retardancy, antibacterialness, and antifouling, as follows: a. The latex particles in the self-made multifunctional modified acrylic emulsion of the present invention have a phosphorus-enriched core layer constructed with HEMAP flame-retardant monomers, which cooperates with the ADP synergist in the coating system to form a gas-phase-solid phase flame retardant mechanism, so that when the coating burns, a dense carbon layer is formed, which more effectively isolates oxygen and heat transfer; b. Lasting antibacterial properties: The latex particle shell layer in the self-made multifunctional modified acrylic ester emulsion of the present invention is grafted with a quaternary ammonium salt, which kills bacteria through physical contact and gives the coating good antibacterial stability; In addition, the coating formula of the present invention also adds nano-SiO2 silver-loaded photocatalyst, nano-Si The silver-loaded photocatalyst constructs a multi-level, efficient, and long-lasting antibacterial system through the contact sterilization of silver ions, the oxidation sterilization of ROS generated by photocatalysis, and the electronic conduction enhancement effect of silver nanoparticles, further improving the antibacterial properties of the coating. c. Long-lasting antifouling properties: Fluorosilicone monomer (DFMA / KH-570) is introduced into the latex particle structure of the self-made multifunctional modified acrylic emulsion of the present invention, which can form a low surface energy layer on the coating surface, giving the coating good anti-fouling properties; (2) The antibacterial, antifouling, and flame-retardant water-based paint for building exterior walls obtained by the present invention can be applied in an environment of 5-40°C, effectively solving the bottleneck of winter painting. The porous fillers (such as wollastonite) added to the antibacterial, antifouling, and flame-retardant water-based paint for building exterior walls obtained by the present invention construct complex microchannels, which can effectively prevent bubbling and shedding of the coating; (3) The multifunctional modified acrylic emulsion obtained in the present invention is a molecular-level coating design of flame-retardant core (HEMAP)-antifouling layer (fluorosilicone)-antibacterial shell (quaternary ammonium salt, guanidine salt), which can avoid the migration and failure of functional components; (4) The present invention adopts a one-pot method to synthesize the emulsion, which simplifies the process and shortens the production cycle by at least 30%. The coating system of the present invention supports cheap mineral fillers such as calcined kaolin and heavy calcium carbonate (addition amount ≤ 8%), and the raw material cost is reduced by 15-20%. DETAILED DESCRIPTION

[0018] The present invention will be described in detail below with reference to the following examples. However, it should be understood that the following examples are merely illustrative of the embodiments of the present invention and are not intended to limit the scope of the present invention.

[0019] The wetting agent used in the following examples of the present invention is the non-ionic wetting agent Dynol 360.

[0020] The thickener used in the following examples of the present invention is Rohm and Haas RM-8W.

[0021] The environmentally friendly film-forming aid used in the following examples of the present invention is alcohol ester twelve.

[0022] The dispersant used in the following examples of the present invention is Arkema COADIS 790.

[0023] The multifunctional modified acrylate emulsion in the following embodiments of the present invention is prepared by the following raw materials in parts by weight: HEMAP 100 copies; BA 400 copies; MMA 320 copies; AA 20 copies; DFMA 80 copies; KH-570 40 parts; 30 parts of antibacterial monomer; CO-436 15 copies; APS 8 copies; 4 parts of sodium bicarbonate; ADP 15 copies; 2500 parts of deionized water; The antibacterial monomer is composed of DMAE-HB and (acryloyloxyethyl)guanidine hydrochloride in a mass ratio of 3:1.

[0024] The preparation method of the multifunctional modified acrylic ester emulsion comprises the following steps, calculated in parts by weight: (1) Preparation of pre-emulsion At room temperature, 1 / 4 of the formulated amount of HEMAP, 3 / 8 of the formulated amount of BA, 5 / 16 of the formulated amount of MMA, 1 / 3 of the formulated amount of emulsifier, and 15 / 122 of the formulated amount of water were mixed uniformly, and triethylamine was added dropwise while stirring to adjust the pH of the reaction system to 6 to obtain a homogeneous emulsification to form a pre-emulsion; (2) Add 30 / 61 of water and 1 / 5 of emulsifier to the reactor, stir and heat to 82±0.5°C under nitrogen protection, add initiator solution I to the reaction system, stir evenly, and then add 10% of the total mass of pre-emulsion to the reaction system while stirring, keep warm and stir for at least 30 minutes to obtain seed emulsion; (3) The remaining amount of BA, the remaining amount of MMA, the remaining amount of DFMA, the remaining amount of KH-570, the remaining amount of AA, the remaining amount of emulsifier, and 35 / 122 of water are stirred and mixed to obtain a fluorine-modified emulsion; (4) Lowering the temperature of the seed emulsion to 80±1°C, adding the initiator solution II and the fluorine-modified emulsion dropwise to the seed emulsion obtained in step (3) while stirring, and completing the addition within 4 hours to obtain a fluorine-modified polymer emulsion; (5) Lower the temperature of the fluorine-modified polymer emulsion to 60±1°C, add the antibacterial monomer solution dropwise while stirring, and complete the addition within 40 minutes. Add the initiator solution III while stirring, and keep the reaction at 60°C for at least 1 hour. Then lower the temperature of the reaction system to 40°C, add the formulated amount of ADP, stir evenly, adjust the pH of the reaction system to 8.0, filter the material, and obtain a multifunctional modified acrylate emulsion; The initiator solution I is a mixture of 6 / 17 of APS and 5 / 244 of water, the initiator solution II is a mixture of 10 / 17 of APS and 3 / 61 of water, the quaternary ammonium salt solution is a mixture of the antibacterial monomer and 1 / 50 of water, and the initiator solution III is a mixture of the remaining amount of APS and the remaining amount of water.

[0025] The emulsifier used in the present invention is Solvay multifunctional emulsifier CO-436.

[0026] Example 1

[0027] An antibacterial, antifouling, and flame-retardant water-based paint for building exterior walls, comprising the following raw material components, calculated by weight percentage: Multifunctional modified acrylic emulsion 30%; Fluorosilicone modified hydrophobic agent 1%; Photocatalytic antibacterial agent 2%; Filler 3%; Dispersant 0.5%; Wetting agent 0.5%; Thickener 0.2%; Environmentally friendly film-forming agent 1%; Water balance.

[0028] The fluorosilicone modified hydrophobic agent is HY-4100 lotus leaf fluorosilicone hydrophobic agent.

[0029] The nano-silicon dioxide silver-loaded antibacterial agent is VK-T07 from Jingrui New Materials.

[0030] The filler is a mixture of wollastonite and ground calcium carbonate in a mass ratio of 1:1. The average particle size of the wollastonite is 10 μm, and the average particle size of the ground calcium carbonate is 20 μm.

[0031] Example 2

[0032] An antibacterial, antifouling, and flame-retardant water-based paint for building exterior walls, comprising the following raw material components, calculated by weight percentage: Multifunctional modified acrylic emulsion 45%; Fluorosilicone modified hydrophobic agent 3%; Photocatalytic antibacterial agent 5%; Filler 8%; Dispersant 1.5%; Wetting agent 1.5%; Thickener 0.8%; Environmentally friendly film-forming agent 2%; Water balance.

[0033] The fluorosilicone modified hydrophobic agent is a high-penetration organic silicone waterproofing agent SH-F23.

[0034] The nano-silicon dioxide silver-loaded antibacterial agent is Hangzhou Jiuli JL-TAg10.

[0035] The filler is a mixture of calcined kaolin and wollastonite in a mass ratio of 1:2. The average particle size of the calcined kaolin is 15 μm, and the average particle size of the wollastonite is 10 μm.

[0036] Example 3

[0037] An antibacterial, antifouling, and flame-retardant water-based paint for building exterior walls, comprising the following raw material components, calculated by weight percentage: Multifunctional modified acrylic emulsion 38%; Fluorosilicone modified hydrophobic agent 2%; Photocatalytic antibacterial agent 3%; Filler 5%; Dispersant 1%; Wetting agent 1%; Thickener 0.5%; Environmentally friendly film-forming agent 1.5%; Water balance.

[0038] The fluorosilicone modified hydrophobic agent is a high-penetration organic silicone waterproofing agent SH-F23.

[0039] The nano-silicon dioxide silver-loaded antibacterial agent is VK-T07 from Jingrui New Materials.

[0040] The filler is a mixture of calcined kaolin and ground calcium carbonate in a mass ratio of 1:1. The average particle size of the calcined kaolin is 15 μm, and the average particle size of the ground calcium carbonate is 20 μm.

[0041] Example 4

[0042] An antibacterial, antifouling, and flame-retardant water-based paint for building exterior walls, comprising the following raw material components, calculated by weight percentage: Multifunctional modified acrylic emulsion 42%; Fluorosilicone modified hydrophobic agent 2%; Photocatalytic antibacterial agent 3%; Filler 6%; Dispersant 1%; Wetting agent 1%; Thickener 0.4%; Environmentally friendly film-forming agent 1.5%; Water balance.

[0043] The fluorosilicone modified hydrophobic agent is HY-4100 lotus leaf fluorosilicone hydrophobic agent.

[0044] The nano-silicon dioxide silver-loaded antibacterial agent is Hangzhou Jiuli JL-TAg10.

[0045] The filler is a mixture of wollastonite and ground calcium carbonate in a ratio of 2:1. The average particle size of the wollastonite is 10 μm, and the average particle size of the ground calcium carbonate is 20 μm.

[0046] Comparative Example 1 is the same as Example 1, except that the multifunctional modified acrylate emulsion in Example 1 is replaced by an equal amount of BASF Acronal PLUS 7676 pure acrylic emulsion.

[0047] Comparative Example 2 is the same as Example 1, except that the multifunctional modified acrylic ester emulsion in Example 1 is replaced by the water-based acrylic emulsion E0503-X of Shenzhen Jitian Chemical with the same addition amount.

[0048] Comparative Example 3 is the same as Example 1, except that the antibacterial monomer used in the preparation of the multifunctional modified acrylate emulsion in Comparative Example 3 consists of DMAE-HB and (acryloyloxyethyl)guanidine hydrochloride in a mass ratio of 1:1.

[0049] Comparative Example 4 is the same as Example 1, except that the antibacterial monomer used in the preparation of the multifunctional modified acrylate emulsion in Comparative Example 4 consists of DMAE-HB and (acryloyloxyethyl)guanidine hydrochloride in a mass ratio of 1:3.

[0050] Comparative Example 5 is the same as Example 1, except that no fluorosilicone modified hydrophobic agent is added in Comparative Example 5.

[0051] Comparative Example 6 is the same as Example 1, except that no photocatalytic antibacterial agent is added in Comparative Example 6.

[0052] Comparative Example 7 is the same as Example 1, except that the weight portions of DFMA and KH-570 in the raw material composition of the multifunctional modified acrylic emulsion in Comparative Example 7 are both 60 parts.

[0053] Comparative Example 8 is the same as Example 1, except that the weight portions of DFMA and KH-570 in the raw material composition of the multifunctional modified acrylic ester emulsion in Comparative Example 8 are 40 parts and 80 parts, respectively.

[0054] Comparative Example 9 is the same as Example 1, except that the antibacterial monomer in Comparative Example 9 is DMAE-HB.

[0055] Performance testing: The water-based coatings for building exterior walls obtained in Examples 1-5 of the present invention and Comparative Examples 1-9 were respectively subjected to relevant performance tests, and the specific test results are shown in Table 2, Table 3, and Table 3.

[0056] The performance test standards and basis are shown in Table 1: Table 1

[0057] The specific test results are shown in Table 2, Table 3, and Table 3: Table 2

[0058] Table 3

[0059] Table 3

[0060] Combining the test results in Tables 2 and 3, we can see that the HEMAP phosphorus-based flame-retardant core in the multifunctional modified acrylic emulsion in Example 1 pyrolyzes to form polyphosphoric acid, which catalytically dehydrates to form carbon. The ADP in the coating formulation, upon heating, releases PO radicals, which interrupt the chain reaction in the gas phase. This dual-action mechanism of "solid carbon layer + gas-phase dilution" formed by the HEMAP phosphorus-based flame-retardant core and ADP significantly improves the flame retardancy of the coating. Comparative Examples 1-2 (LOI <25%): This is because the conventional acrylic emulsion lacks a flame-retardant structure and relies solely on the physical barrier of the filler.

[0061] The antibacterial properties of the coatings obtained in Examples 1-4 for 28 days were all greater than 98.9%, which was due to the synergistic effect of the dual antibacterial monomer and the photocatalyst. DMAE-HB (quaternary ammonium salt) destroyed the cell membrane, (acryloyloxyethyl)guanidine hydrochloride penetrated and interfered with DNA replication, and Ti @Ag generates OH free radicals under ultraviolet light to decompose residual bacterial corpses (preventing biofilm regeneration).

[0062] The antibacterial rate of the coating 28d obtained in Comparative Example 6 is about 85.7%, which is due to the lack of photocatalytic components and the accumulation of bacterial corpses, resulting in antibacterial decline.

[0063] The antibacterial rates of the coatings 28d obtained in Comparative Examples 3-4 were significantly lower than those in Example 1, possibly because the excessively high proportion of guanidine salt reduced the targeting of the quaternary ammonium salt membrane.

[0064] The ΔE of the coatings obtained in Examples 1-4 was ≤ 2.0, which was due to the synergistic effect of DFMA (fluorocarbon chain) in reducing surface energy and KH-570 (siloxane) in enhancing crosslinking density, forming a low adhesion surface (contact angle > 112°).

[0065] However, since the coating obtained in Comparative Example 5 does not contain a fluorine-silicon modified hydrophobic agent, the ΔE of the coating obtained is 7.1, and pollutants are easily infiltrated and attached to the coating surface.

[0066] In Comparative Example 7-8, due to the imbalance in the ratio of DFMA and KH-570, the molecular arrangement is disordered, resulting in an increase in surface energy, and then making ΔE>4.5.

[0067] The single quaternary ammonium salt in Comparative Example 9 cannot solve the problems of Gram-positive bacteria penetration and biofilm regeneration, resulting in a simultaneous decline in antibacterial rate, stain resistance, and flame retardancy; at the same time, interfacial corrosion and moisture absorption expansion caused by the biofilm are the main reasons for the decline in adhesion and water resistance.

[0068] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. An antibacterial, antifouling and flame-retardant water-based paint for building exterior walls, characterized in that: Calculated by mass percentage, it includes the following raw materials: Multifunctional modified acrylic emulsion 30-45%; Fluorosilicone modified hydrophobic agent 1-3%; Photocatalytic antibacterial agent 2-5%; Filler 3-8%; Dispersant 0.5-1.5%; Wetting agent 0.5-1.5%; Thickener 0.2-0.8%; Environmentally friendly film-forming agent 1-2%; Water balance.

2. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to claim 1, characterized in that: The multifunctional modified acrylic ester emulsion is prepared by including the following raw materials in parts by weight: HEMAP 95-100 copies; BA 390-400 copies; MMA 310-320 copies; AA 18-20 servings; DFMA 76-80 copies; KH-570 38-40 parts; 25-30 parts of antibacterial monomer; 12-15 parts of emulsifier; 6-8 parts of initiator; 3-4 parts sodium bicarbonate; ADP 13-15 copies; 2400-2500 parts of deionized water; The antibacterial monomer is composed of DMAE-HB and (acryloyloxyethyl)guanidine hydrochloride in a mass ratio of 2-3:

1.

3. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to any one of claims 1 to 2, characterized in that: The preparation method of the multifunctional modified acrylic ester emulsion comprises the following steps, calculated in parts by weight: (1) Preparation of pre-emulsion At room temperature, the formulated amount of HEMAP, 3 / 8 of the formulated amount of BA, 5 / 16 of the formulated amount of MMA, 1 / 3 of the formulated amount of emulsifier, and 15 / 122 of the formulated amount of water were uniformly mixed, and triethylamine was added dropwise while stirring to adjust the pH of the reaction system to 6-7 to obtain a homogeneous emulsification to form a pre-emulsion; (2) Add 30 / 61 of water and 1 / 5 of emulsifier to the reactor, stir and heat to 82±0.5°C under nitrogen protection, add initiator solution I to the reaction system, stir evenly, and then add 10% of the total mass of pre-emulsion to the reaction system while stirring, keep warm and stir for at least 30 minutes to obtain seed emulsion; (3) The remaining amount of BA, the remaining amount of MMA, the remaining amount of DFMA, the remaining amount of KH-570, the remaining amount of AA, the remaining amount of emulsifier, and 35 / 122 of water are stirred and mixed to obtain a fluorine-modified emulsion; (4) Lowering the temperature of the seed emulsion to 80±1°C, adding the initiator solution II and the fluorine-modified emulsion dropwise to the seed emulsion obtained in step (3) while stirring, and completing the addition within 4 hours to obtain a fluorine-modified polymer emulsion; (5) Lower the temperature of the fluorine-modified polymer emulsion to 60±1°C, add the antibacterial monomer solution dropwise while stirring, and complete the addition within 40 minutes. Add the initiator solution III while stirring, and keep the reaction at 60°C for at least 1 hour. Then lower the temperature of the reaction system to 40°C, add the formulated amount of ADP, stir evenly, adjust the pH of the reaction system to 8.0, filter the material, and obtain a multifunctional modified acrylate emulsion; The initiator solution I is a mixture of 6 / 17 of APS and 5 / 244 of water, the initiator solution II is a mixture of 10 / 17 of APS and 3 / 61 of water, the quaternary ammonium salt solution is a mixture of the antibacterial monomer and 1 / 50 of water, and the initiator solution III is a mixture of the remaining amount of APS and the remaining amount of water.

4. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to claim 1, characterized in that: The fluorosilicone modified hydrophobic agent is HY-4100 lotus leaf fluorosilicone hydrophobic agent or high permeability organic silicon waterproofing agent SH-F23.

5. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to claim 1, characterized in that: The photocatalytic antibacterial agent is a nano-silicon dioxide-loaded silver antibacterial agent.

6. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to claim 4, characterized in that: The nano-silicon dioxide silver-loaded antibacterial agent includes Jingrui New Materials VK-T07 or Hangzhou Jiuli JL-TAg10.

7. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to claim 1, characterized in that: The filler includes one or more of calcined kaolin, wollastonite or heavy calcium carbonate.

8. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to claim 1, characterized in that: The dispersant includes a nonionic dispersant or an anionic sodium salt dispersant.

9. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to claim 1, characterized in that: The wetting agent is a nonionic wetting agent HYDRAPOL RP50 or a nonionic wetting agent Dynol 360.

10. The antibacterial, antifouling and flame-retardant water-based paint for building exterior walls according to claim 1, characterized in that: The thickener is a nonionic associative thickener.

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