Flexible modified water-based fluorocarbon concrete protective coating and preparation method thereof

Abstract

The invention discloses a flexible modified water-based fluorocarbon concrete protective coating and a preparation method thereof, and belongs to the field of coatings. Water-based fluorocarbon resin main film-forming matter resin containing 20% of active hydroxyl is selected, the flexibility of a coating is provided by adding a self-made SiO2 modified flexible chain segment-containing prepolymer, and the flexibility of the resin is enhanced by introducing flexible chain segments such as polyester polyol and the like into the flexible prepolymer; meanwhile, the SiO2 inorganic part is introduced, so that the strength of the coating can be enhanced, the antifouling performance of the surface of the fluorocarbon coating is further enhanced, and meanwhile, the ultraviolet aging resistance of the coating is further improved by adding the inorganic nano ultraviolet light absorber into the polymer. A water-dispersed isocyanate curing agent is selected as a curing agent to realize further cross-linking and film forming of the space of the coating, and finally, the flexible modified water-based fluorocarbon concrete protective coating with super weather resistance, dirt resistance and high elongation at break is prepared and can provide more durable anti-corrosion protection for the surface of concrete.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a flexible modified water-based fluorocarbon concrete protective coating with super weather resistance, anti-fouling, and high elongation at break, and a preparation method thereof. Background Art

[0002] As one of the most important methods for protecting building concrete, external concrete protection technology leverages the inherent properties of protective materials and the physical and chemical interactions they produce with the substrate to effectively protect the base. The proper selection of protective materials and the rational construction of the protection system can effectively prevent rainwater, snowwater, and groundwater from leaking into the building's occupied spaces through the roof, walls, foundations, or joints of concrete components. It also blocks corrosive media such as salt from penetrating into building components or foundations, preventing the resulting performance degradation and failure. Water-based paints contain little or no volatile organic compounds (VOCs) and no hazardous air pollutants (HAPs), thus contributing to the rational use of resources, environmental protection, and human health. They have become a new development direction in coatings technology.

[0003] Due to the hard and brittle nature of traditional fluorocarbon coatings, coatings prepared with these coatings experience reduced elongation at break and tensile strength after service in corrosive environments, UV exposure, and environmental aging. This increases the risk of cracking and delamination over extended use. However, increasing the coating's flexibility and self-healing properties significantly increases the service life of fluorocarbon coatings. According to the JT / T821-2011 standard, "Anti-corrosion Coatings for Steel Structures on Concrete Bridges," the primary composition of a waterborne anti-corrosion coating is a waterborne epoxy primer, an acrylic intermediate, and a waterborne fluorocarbon topcoat. Currently, waterborne fluorocarbon concrete protective coatings are typically formulated using a two-component fluorocarbon coating based on a flexible fluorocarbon resin emulsion. After 2500 hours of artificial UV aging, high-quality flexible fluorocarbon coatings exhibit a tensile strength retention of ≥85% and an elongation at break of >130%, and can still cover microcracks (≤0.3mm) in concrete. Inferior products, due to insufficient fluorocarbon resin purity or uneven dispersion, experience a decrease in flexibility of over 30% after UV exposure, potentially leading to brittle cracking of the coating. At the same time, the addition of excessive nano-antibacterial agents (>3%) will accelerate the loss of hydrophobicity, and the contact angle will drop by 40% under ultraviolet radiation. Summary of the Invention

[0004] The present invention discloses a flexible modified water-based fluorocarbon concrete protective coating and a preparation method thereof. The present invention selects a water-based fluorocarbon resin containing 20% ​​active hydroxyl groups as the main film-forming resin, and provides the flexibility of the coating by adding a self-made SiO2-modified prepolymer containing flexible segments. The flexible prepolymer not only enhances the flexibility of the resin by introducing flexible segments such as polyester polyols, but also introduces the SiO2 inorganic part to enhance the strength of the coating and further enhance the anti-fouling performance of the fluorocarbon coating surface. At the same time, an inorganic nano-ultraviolet absorber is added to the polymer to further enhance the coating's resistance to ultraviolet aging. The curing agent selects a water-dispersible isocyanate curing agent to achieve further spatial cross-linking and film formation of the coating, and finally prepares a flexible modified water-based fluorocarbon concrete protective coating with super weather resistance, anti-fouling, and high elongation at break, which can provide more durable anti-corrosion protection for the concrete surface.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A flexible modified water-based fluorocarbon concrete protective coating, comprising component A and component B:

[0007] Component A consists of the following ingredients:

[0008]

[0009] Component B consists of the following ingredients:

[0010] 10-30 parts of diluent

[0011] 0.1-3 parts of dehydrating agent

[0012] 50-80 parts of water-based isocyanate curing agent.

[0013] In some preferred technical solutions, the component comprises component A and component B:

[0014] Component A consists of the following ingredients:

[0015]

[0016]

[0017] Component B consists of the following ingredients:

[0018] 25-30 parts of diluent

[0019] 0.5-2 parts of dehydrating agent

[0020] 55-70 parts of water-based isocyanate curing agent.

[0021] In the technical solution of the present invention, the SiO2 modified prepolymer containing flexible segments is composed of the following components:

[0022]

[0023] In the technical solution of the present invention, the inorganic ultraviolet absorber is any one of a nano-cerium oxide dispersion and a nano-titanium oxide dispersion; further preferably, the nano-cerium oxide dispersion is JL103 from Beijing Dekedao Gold Technology Co., Ltd., and the nano-titanium oxide dispersion is JL106 from Beijing Dekedao Gold Technology Co., Ltd.;

[0024] Preferably, the alkoxysilane monomer is at least one of methyltriethoxysilane, methyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, and ethyl orthosilicate;

[0025] Preferably, the isocyanate silane monomer is one of 3-isocyanate propyltrimethoxysilane and 3-isocyanate propyltriethoxysilane;

[0026] The polymer polyol is selected from any one of polyester diol (CAS: 68082-28-0), polyether diol (CAS: 29434-03-5), and polycarbonate diol (CAS: 24937-06-2);

[0027] The cosolvent is a mixture of one or more of propylene glycol methyl ether acetate (CAS: 108-65-6), propylene glycol methyl ether (CAS: 107-98-2), dipropylene glycol butyl ether (CAS: 29911-28-2), ethylene glycol butyl ether (CAS: 111-76-2), and dipropylene glycol methyl ether (CAS: 34590-94-8).

[0028] In the technical solution of the present invention, the preparation method of the SiO2 modified prepolymer containing flexible segments is:

[0029] (1) an inorganic ultraviolet absorber, deionized water, and glacial acetic acid are mechanically stirred and mixed, and then an alkoxysilane monomer is added and stirred at room temperature for 1 to 3 hours to prepare a hydrolyzed solution;

[0030] (2) The polymer polyol, isocyanate silane monomer and cosolvent are mixed and reacted at room temperature for 2 hours. After the NCO content is measured to be less than 0.5%, the hydrolyzate prepared in step (1) is added and heated to 60° C. for 2 hours. After cooling the system, the material is discharged to obtain SiO2 modified prepolymer containing flexible segments.

[0031] In the technical solution of the present invention, the water-based fluorocarbon resin is the water-based resin WF-D2245 produced by Wanbo New Materials Technology (Nantong) Co., Ltd.

[0032] The pigment is a weather-resistant pigment, which can be one or more of carbon black, phthalocyanine blue, organic scarlet, organic medium yellow and rutile titanium dioxide;

[0033] The cosolvent is a mixture of one or more of propylene glycol methyl ether acetate, propylene glycol methyl ether, dipropylene glycol butyl ether, ethylene glycol butyl ether, and dipropylene glycol methyl ether;

[0034] The dispersant is a water-based pigment dispersant, which is any one of Shenzhu SN1790 and SN1798;

[0035] The wetting agent is a polyether modified silicone wetting agent, the brand is Shenzhu SN4741;

[0036] The defoaming agent is selected from any one of Shenzhu SN6710 and SN6788;

[0037] The thickener is an associative polyurethane thickener, the brand is Wanhua U605.

[0038] In the technical solution of the present invention, the water-based isocyanate curing agent in component B refers to a water-dispersible isocyanate curing agent, preferably: the water-based isocyanate curing agent is Wanhua 268. Wanhua 278. Wanhua One of 280 or any combination thereof;

[0039] The diluent is one or more of ethylene glycol butyl ether acetate, ethylene glycol methyl ether acetate, propylene glycol methyl ether, and propylene glycol methyl ether acetate in any combination;

[0040] The dehydrating agent is Shenzhu SN-9088.

[0041] The above-mentioned flexible modified water-based fluorocarbon concrete protective coating is prepared by the following method:

[0042] (3) Preparation of component A: Deionized water, dispersant, and pigment are mixed, stirred evenly, and ground to a fineness of ≤20 μm to prepare a color paste; SiO2-modified prepolymer containing flexible segments is added to the water-based fluorocarbon resin and stirred using a high-speed stirrer, and color paste, cosolvent, wetting agent, defoamer, and thickener are added and stirred and dispersed thoroughly to obtain a uniformly mixed coating component A;

[0043] (4) Preparation of component B: Mix the diluent and dehydrating agent and stir evenly; then add the water-based isocyanate curing agent and stir evenly to obtain component B;

[0044] (3) Component A and component B are mixed evenly in a mass ratio of 5 to 8:1 to obtain the target product.

[0045] Beneficial effects of the present invention:

[0046] (1) The flexibility of the coating is provided by adding a self-made SiO2-modified prepolymer containing a flexible chain segment. The flexible prepolymer first enhances the flexibility of the coating by introducing a polyester polyol flexible chain segment. At the same time, the introduction of the SiO2 inorganic part can enhance the strength of the coating and further enhance the antifouling performance of the fluorocarbon coating surface. Different from the physical mixing in the flexible fluorocarbon coating, the technical advantage of the present invention is that the Si-O-Si bond is connected to the polyester polyol flexible chain segment by a chemical grafting method to prepare a second film-forming substance, which effectively supplements the lack of flexibility of the first film-forming substance and provides the coating with a certain tensile strength and elongation at break, which can ensure that the coating maintains flexibility and coating integrity during the aging process.

[0047] (2) Inorganic nano-UV absorbers are creatively added to the polymer using a sol-gel method. Unlike the problem of poor dispersibility of nanomaterials in organic film-forming materials caused by direct mixing and addition, the silanol group (Si-OH) produced by the hydrolysis of siloxane is dehydrated and condensed with the hydroxyl group on the surface of titanium oxide or cerium oxide through the sol-gel method to form a Si-O-Ti / Ce bond. The inorganic chain segment Si-O-Ti / Ce with UV absorption function is further grafted with polyester polyol through reaction, and finally undergoes a curing reaction with the isocyanate curing agent to form a three-dimensional network. In this way, the UV absorber is stably dispersed in the coating, which can effectively improve the UV aging resistance of the coating.

[0048] Finally, the present invention prepares a flexible modified water-based fluorocarbon concrete protective coating with super weather resistance, anti-fouling, and high elongation at break, which can provide more durable anti-corrosion protection for the concrete surface. DETAILED DESCRIPTION

[0049] The present invention will be further described below with reference to the embodiments, but the protection scope of the present invention is not limited thereto.

[0050] The sources of components used in the examples are as follows:

[0051] The nano-cerium oxide dispersion is JL103 from Beijing Dekedaojin Technology Co., Ltd., and the nano-titanium oxide dispersion is JL106 from Beijing Dekedaojin Technology Co., Ltd.

[0052] The water-based fluorocarbon resin is the water-based resin WF-D2245 of Wanbo New Materials Technology (Nantong) Co., Ltd.

[0053] The dispersant is a water-based pigment dispersant, which is any one of Shenzhu SN1790 and SN1798;

[0054] The wetting agent is a polyether modified silicone wetting agent, the brand is Shenzhu SN4741;

[0055] The defoaming agent is selected from any one of Shenzhu SN6710 and SN6788;

[0056] The thickener is an associative polyurethane thickener, the brand is Wanhua U605.

[0057] The water-based isocyanate curing agent is Wanhua 268. Wanhua 278. Wanhua One of 280 or any combination thereof;

[0058] The dehydrating agent is Shenzhu SN-9088.

[0059] Example 1:

[0060] Add 5g of nano-titanium oxide dispersion (JL106, Beijing Dekedaojin Technology Co., Ltd.), 5g of deionized water, and 1g of glacial acetic acid into a three-necked flask and stir mechanically to mix. Then add 30g of methyltriethoxysilane and stir at room temperature for 2 hours to obtain a hydrolyzate. Separately, add 10g of polyether diol, 20g of polyester diol, 10g of 3-isocyanatepropyltriethoxysilane, and 15g of propylene glycol methyl ether acetate into a new three-necked flask and react at room temperature for 2 hours. After the NCO content is measured to be less than 0.1%, add the hydrolyzate obtained in the first step and heat to 60°C for 2 hours. After cooling the system, discharge the material to obtain SiO2-modified flexible segment-containing prepolymer F1.

[0061] Example 2:

[0062] Add 5g of nano-cerium oxide dispersion (JL103, Beijing Dekedao Gold Technology Co., Ltd.), 5g of deionized water, and 1g of glacial acetic acid into a three-necked flask and stir mechanically to mix. Then add 30g of methyltriethoxysilane and stir at room temperature for 2 hours to obtain a hydrolyzate. Separately, add 10g of polyether diol, 20g of polyester diol, 10g of 3-isocyanatepropyltriethoxysilane, and 15g of propylene glycol methyl ether acetate into a new three-necked flask and react at room temperature for 2 hours. After the NCO content is measured to be less than 0.1%, add the hydrolyzate obtained in the first step and heat to 60°C for 2 hours. After cooling the system, discharge the material to obtain SiO2-modified flexible segment-containing prepolymer F2.

[0063] Example 3:

[0064] 14g deionized water, 1g dispersant SN1790 and 10g rutile titanium dioxide were mixed, stirred evenly and ground to a fineness of ≤20μm to prepare titanium dioxide slurry; 20g SiO2 modified prepolymer F1 containing flexible chain segments was added to 49g water-based fluorocarbon resin WF-D2245 and stirred with a high-speed stirrer, and then 25g titanium dioxide slurry, 5g propylene glycol methyl ether acetate, 0.2g wetting agent SN4741, 0.2g defoamer SN6710 and 0.6g thickener were added. The uniformly mixed coating component A obtained after U605 is fully stirred and dispersed is marked as A1;

[0065] Example 4:

[0066] 14g of deionized water, 1g of dispersant SN1790 and 10g of rutile titanium dioxide were mixed, stirred evenly and ground to a fineness of ≤20μm to prepare a titanium dioxide slurry; 15g of SiO2 modified prepolymer F1 containing flexible segments was added to 54g of water-based fluorocarbon resin WF-D2245 and stirred with a high-speed stirrer, and then 25g of titanium dioxide slurry, 5g of propylene glycol methyl ether acetate, 0.2g of wetting agent SN4741, 0.2g of defoaming agent SN6710 and 0.6g of thickener were added. The uniformly mixed coating component A obtained after U605 is fully stirred and dispersed is marked as A2;

[0067] Example 5:

[0068] 14g deionized water, 1g dispersant SN1790 and 10g rutile titanium dioxide were mixed, stirred evenly and ground to a fineness of ≤20μm to prepare titanium dioxide slurry; 10g SiO2 modified prepolymer containing flexible chain segments F1 was added to 59g water-based fluorocarbon resin WF-D2245 and stirred with a high-speed stirrer, and then 25g titanium dioxide slurry, 5g propylene glycol methyl ether acetate, 0.2g wetting agent SN4741, 0.2g defoamer SN6710 and 0.6g thickener were added. The uniformly mixed coating component A obtained after U605 is fully stirred and dispersed is marked as A3;

[0069] Example 6:

[0070] 14g deionized water, 1g dispersant SN1790 and 10g rutile titanium dioxide were mixed, stirred evenly and ground to a fineness of ≤20μm to prepare titanium dioxide slurry; 20g SiO2 modified prepolymer F2 containing flexible chain segments was added to 49g water-based fluorocarbon resin WF-D2245 and stirred with a high-speed stirrer, and then 25g titanium dioxide slurry, 5g propylene glycol methyl ether acetate, 0.2g wetting agent SN4741, 0.2g defoamer SN6710 and 0.6g thickener were added. After U605 is fully stirred and dispersed, the uniformly mixed coating component A is marked as A4;

[0071] Example 7:

[0072] 14g of deionized water, 1g of dispersant SN1790 and 10g of rutile titanium dioxide were mixed, stirred evenly and ground to a fineness of ≤20μm to prepare a titanium dioxide slurry; 15g of SiO2 modified prepolymer F2 containing flexible segments was added to 54g of water-based fluorocarbon resin WF-D2245 and stirred with a high-speed stirrer, and then 25g of titanium dioxide slurry, 5g of propylene glycol methyl ether acetate, 0.2g of wetting agent SN4741, 0.2g of defoaming agent SN6710 and 0.6g of thickener were added. The uniformly mixed coating component A obtained after U605 is fully stirred and dispersed is marked as A5;

[0073] Example 8:

[0074] 14g deionized water, 1g dispersant SN1790 and 10g rutile titanium dioxide were mixed, stirred evenly and ground to a fineness of ≤20μm to prepare titanium dioxide slurry; 10g SiO2 modified prepolymer F2 containing flexible segments was added to 59g water-based fluorocarbon resin WF-D2245 and stirred with a high-speed stirrer, and then 25g titanium dioxide slurry, 5g propylene glycol methyl ether acetate, 0.2g wetting agent SN4741, 0.2g defoamer SN6710 and 0.6g thickener were added. After U605 is fully stirred and dispersed, the uniformly mixed coating component A is marked as A6;

[0075] Example 9

[0076] 14g deionized water, 1g dispersant SN1790 and 10g rutile titanium dioxide were mixed, stirred evenly and ground to a fineness of ≤20μm to prepare titanium dioxide slurry; 69g water-based fluorocarbon resin WF-D2245 was added and stirred with a high-speed mixer, and 25g titanium dioxide slurry, 5g propylene glycol methyl ether acetate, 0.2g wetting agent SN4741, 0.2g defoamer SN6710 and 0.6g thickener were added. The uniformly mixed coating component A obtained after U605 is fully stirred and dispersed is marked as A7;

[0077] Example 10

[0078] Mix 29g of propylene glycol methyl ether acetate and 1g of dehydrating agent SN-9088 and stir evenly; then add 70g of isocyanate curing agent 268, stirring at low speed to obtain curing agent component B;

[0079] Example 11

[0080] A-1, A-2, A-3, A-4, A-5, A-6 and B were respectively prepared in a mass ratio of 8:1 to obtain flexible modified waterborne fluorocarbon concrete protective coatings E1 to E6;

[0081] Comparative Example 1:

[0082] A-7 and B are prepared in a mass ratio of 8:1 to obtain water-based fluorocarbon concrete protective coating E7.

[0083] The coating is applied on the surface of the concrete slab as required, and the coating performance is tested according to some requirements of the standard JT / T821-2011 "Anti-corrosion coatings for the surface of concrete bridge steel structures".

[0084] Table 1 Requirements for matching coating panels for concrete bridges

[0085]

[0086] Table 2 Test standards for water-based fluorocarbon topcoat

[0087]

[0088] Table 3 Supporting system test

[0089]

[0090] Table 4 Performance test of flexible modified waterborne fluorocarbon concrete protective coating

[0091]

[0092]

[0093] The test results show that Example 12 obtains a flexible modified water-based fluorocarbon concrete protective coating with ultra-long weather resistance, anti-fouling, high coating elongation at break and tensile strength.

[0094] The test results of Comparative Example 1 show that the coating without the addition of SiO2-modified flexible segment prepolymer exhibited gloss loss after both water resistance and alkali resistance tests, indicating that the coating without the addition of SiO2-modified flexible segment prepolymer had poor anti-fouling ability. This is because the Si-O-Ti / Ce inorganic network formed in the SiO2-modified flexible segment prepolymer can greatly block the penetration of corrosive media. At the same time, the presence of Si-O-Si bonds can increase the hydrophobicity of the coating to a certain extent, thereby exerting its anti-fouling effect. It can also be seen that the tensile strength and elongation at break of the coating without the addition of SiO2-modified flexible segment prepolymer are also low and do not meet the standard requirements. This is because the coating without the addition of SiO2-modified flexible segment prepolymer is more rigid after curing, and has lower tensile strength and elongation at break. At the same time, due to the insufficient protection of the rigid coating against concrete microcracks, the protective performance of the coating is more likely to decline, resulting in a loss of anti-fouling performance and aging resistance.

[0095] The coatings E1 to E6 prepared in Example 12 have significantly higher aging resistance than the coating E6 prepared in Comparative Example 1. This is because during the coating aging test, first, nano-ultraviolet absorbers exist in the E1 to E6 coatings and are firmly interspersed in the film-forming resin in the form of Si-O-Ti / Ce inorganic networks, which can capture, absorb and convert ultraviolet light, thereby reducing the oxidative degradation of the coating matrix resin by ultraviolet rays, and reducing the probability of aging reactions such as breakage and cross-linking between resin molecules; at the same time, the Si-O-Ti / Ce and Si-O-Si inorganic networks in the coatings are stably grafted with the organic resin molecules in the coatings by forming chemical bonds, thereby enhancing the cross-linking degree between the resin molecules to a certain extent, improving the density and strength of the coating, thereby improving the coating's ability to resist erosion by external corrosive media (ultraviolet rays, oxygen, water vapor, etc.), and delaying the coating aging process; finally, the flexible chain segments in the coatings can effectively resist the microcracks generated in the concrete during the aging process, maintain the integrity of the coating within a certain range, and thus extend the aging resistance of the coating.

[0096] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A flexible modified water-based fluorocarbon concrete protective coating, characterized in that This component contains component A and component B: Component A consists of the following ingredients: Component B consists of the following ingredients: 10-30 parts of diluent 0.1-3 parts of dehydrating agent 50-80 parts of water-based isocyanate curing agent.

2. The flexible modified water-based fluorocarbon concrete protective coating according to claim 1, characterized in that This component contains component A and component B: Component A consists of the following ingredients: Component B consists of the following ingredients: 25-30 parts of diluent 0.5-2 parts of dehydrating agent 55-70 parts of water-based isocyanate curing agent.

3. The flexible modified water-based fluorocarbon concrete protective coating according to claim 1, characterized in that: The SiO2 modified prepolymer containing flexible segments is composed of the following components:

4. The flexible modified water-based fluorocarbon concrete protective coating according to claim 3, characterized in that: The inorganic ultraviolet absorber is any one of a nano-cerium oxide dispersion and a nano-titanium oxide dispersion; further preferably, the nano-cerium oxide dispersion is JL103 from Beijing Dekedao Gold Technology Co., Ltd., and the nano-titanium oxide dispersion is JL106 from Beijing Dekedao Gold Technology Co., Ltd.; Preferably, the alkoxysilane monomer is at least one of methyltriethoxysilane, methyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, and ethyl orthosilicate; Preferably, the isocyanate silane monomer is one of 3-isocyanate propyltrimethoxysilane and 3-isocyanate propyltriethoxysilane; The polymer polyol is selected from any one of polyester diol (CAS: 68082-28-0), polyether diol (CAS: 29434-03-5), and polycarbonate diol (CAS: 24937-06-2); further preferably, the polymer polyol is a polyether diol and a polyester diol in a mass ratio of 1:1 to 3; The cosolvent is a mixture of one or more of propylene glycol methyl ether acetate (CAS: 108-65-6), propylene glycol methyl ether (CAS: 107-98-2), dipropylene glycol butyl ether (CAS: 29911-28-2), ethylene glycol butyl ether (CAS: 111-76-2), and dipropylene glycol methyl ether (CAS: 34590-94-8).

5. The flexible modified water-based fluorocarbon concrete protective coating according to claim 3, characterized in that: The preparation method of the SiO2 modified prepolymer containing flexible segments is as follows: (1) an inorganic ultraviolet absorber, deionized water, and glacial acetic acid are mechanically stirred and mixed, and then an alkoxysilane monomer is added and stirred at room temperature for 1 to 3 hours to prepare a hydrolyzed solution; (2) The polymer polyol, isocyanate silane monomer and cosolvent are mixed and reacted at room temperature for 2 hours. After the NCO content is measured to be less than 0.5%, the hydrolyzate prepared in step (1) is added and heated to 60° C. for 2 hours. After cooling the system, the material is discharged to obtain SiO2 modified prepolymer containing flexible segments.

6. The flexible modified water-based fluorocarbon concrete protective coating according to claim 1, characterized in that The water-based fluorocarbon resin is the water-based resin WF-D2245 of Wanbo New Materials Technology (Nantong) Co., Ltd. The pigment is a weather-resistant pigment, which can be one or more of carbon black, phthalocyanine blue, organic scarlet, organic medium yellow and rutile titanium dioxide; The cosolvent is a mixture of one or more of propylene glycol methyl ether acetate, propylene glycol methyl ether, dipropylene glycol butyl ether, ethylene glycol butyl ether, and dipropylene glycol methyl ether; The dispersant is a water-based pigment dispersant, which is any one of Shenzhu SN1790 and SN1798; The wetting agent is a polyether modified silicone wetting agent, the brand is Shenzhu SN4741; The defoaming agent is selected from any one of Shenzhu SN6710 and SN6788; The thickener is an associative polyurethane thickener, the brand is Wanhua U605.

7. The flexible modified water-based fluorocarbon concrete protective coating according to claim 1, characterized in that The water-based isocyanate curing agent in component B refers to a water-dispersible isocyanate curing agent, preferably: the water-based isocyanate curing agent is Wanhua 268. Wanhua 278. Wanhua One of 280 or any combination thereof; The diluent is one or more of ethylene glycol butyl ether acetate, ethylene glycol methyl ether acetate, propylene glycol methyl ether, and propylene glycol methyl ether acetate in any combination; The dehydrating agent is any one of the dehydrating agents Shenzhu SN-9088.

8. A flexible modified water-based fluorocarbon concrete protective coating according to claim 1, characterized in that: The preparation method is as follows: (1) Preparation of component A: Deionized water, dispersant, and pigment are mixed, stirred evenly, and ground to a fineness of ≤20 μm to prepare a color paste; SiO2-modified prepolymer containing flexible segments is added to a water-based fluorocarbon resin and stirred using a high-speed stirrer, and color paste, cosolvent, wetting agent, defoamer, and thickener are added and stirred and dispersed thoroughly to obtain a uniformly mixed coating component A; (2) Preparation of component B: Mix the diluent and dehydrating agent and stir evenly; then add the water-based isocyanate curing agent and stir evenly to obtain component B; (3) Component A and component B are mixed evenly in a mass ratio of 5 to 8:1 to obtain the target product.

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