Concrete surface self-cleaning protective coating and preparation method thereof

Abstract

The invention provides a concrete surface self-cleaning protective coating and a preparation method thereof. A component A and a component B are mixed for use at normal temperature according to a mass ratio of A / B = 100 / (5-20); the component A comprises 40 to 60 parts of fluorocarbon resin, 10 to 20 parts of hollow microspheres and 0.1 to 2.5 parts of an anti-biological adhesive agent; and the component B comprises the following components in parts by weight: 65-90 parts of polyisocyanate and 10-35 parts of a high-elasticity prepolymer. The flexibility, elongation, tear resistance and elasticity of the material are improved, the contact angle is increased, and the crack cracking resistance is improved. The concrete surface self-cleaning protective coating guarantees long-term color retention of the coating and is high in safety.

Description

Technical Field

[0001] The invention relates to a self-cleaning protective coating for concrete surface and a preparation method thereof, and is applicable to the field of concrete protection. Background Art

[0002] Compared with wood and ordinary steel, concrete is widely used as a building material because of its easy molding, easy maintenance, cheap and easy to obtain, water resistance, fire resistance, and resistance to cyclic loads. However, the pores larger than 50 microns and the fine cracks that penetrate its structure allow moisture and air to freely enter and exit with degradation factors, thus forming a larger degradation channel, causing the concrete to continue to deteriorate over time. Large-volume concrete such as hydraulic structures, which stand in nature for a long time, are easily attached to and blackened by organisms such as moss; the operating environment in which they are located is very complex, and the outer surface is affected by temperature changes, alternating dry and wet conditions, corrosive media erosion, freeze-thaw cycles, etc., which will cause cracking, carbonization, erosion and other degradation problems, which will gradually expand inward over time and intensify, affecting the service life of the building.

[0003] Unlike metal, glass and other surfaces, the surface of concrete not only has high surface energy and hydrophilicity, but also has porous structures of varying sizes. It is necessary to use a low surface energy film-forming coating to seal the pores to form a smooth surface with low surface energy. Large-scale concrete engineering has complex structures, and the coating needs to be resistant to cracking, immersion, and even have certain resistance to water erosion. Concrete coatings are implemented on-site and are greatly affected by the environment and construction period, so the coating needs to have performance that can adapt to on-site application conditions. Therefore, the common self-cleaning coatings used on metal, glass, and building surfaces are often not suitable for large-volume concrete surfaces such as hydraulic structures.

[0004] This usually requires a cross-linked and cured fluorocarbon resin system to meet the requirements. The coatings currently developed based on the fluorocarbon resin + isocyanate curing agent system have poor tear resistance after curing. They become hard or even brittle over time and are prone to cracking, making it impossible to achieve the purpose of long-term protection of large-volume concrete. Although protective coatings such as polyurea and epoxy have relatively high performance, they are prone to yellowing and powdering, have high surface energy, poor self-cleaning effects, and are expensive, making them unsuitable for large-scale use. Therefore, it is necessary to develop coatings with self-cleaning and protective properties specifically for the characteristics of large-volume concrete surfaces. Summary of the invention

[0005] The purpose of the present invention is to provide a self-cleaning protective coating for concrete surface and a preparation method thereof to solve the problems described in the background technology. To this end, the present invention adopts the following technical solutions:

[0006] A self-cleaning protective coating, composed of component A and component B, characterized in that component A and component B are mixed at a mass ratio of A / B=100 / (5-20) at room temperature;

[0007] In parts by mass, component A comprises: 40-60 parts of fluorocarbon resin, 30-45 parts of diluent, 12-20 parts of tear-resistant resin, 13-18 parts of pigment, 2-10 parts of thixotropic agent, 10-20 parts of hollow microspheres, and 0.1-2.5 parts of anti-biological attachment agent;

[0008] By mass, component B: 65-90 parts of polyisocyanate, 10-35 parts of high elastic prepolymer;

[0009] The fluorocarbon resin is a mixture of solid fluorocarbon resin and liquid fluorocarbon resin in a ratio of 1: (0.1-0.4);

[0010] On the basis of adopting the above technical solutions, the present invention may also adopt the following further technical solutions, or use these further technical solutions in combination:

[0011] The solid fluorocarbon resin refers to an alternating copolymer or graft copolymer of one or two of trifluorochloroethylene monomers or tetrafluoroethylene monomers and one or more of vinyl ether monomers, vinyl ester monomers, vinyl alcohol monomers, and allyl alcohol monomers, with a number average molecular weight of 13000 g / mol to 22000 g / mol and a hydroxyl value of 40 mgKOH / g to 60 mgKOH / g.

[0012] The liquid fluorocarbon resin refers to an alternating copolymer or graft copolymer of one or two of trifluorochloroethylene monomer or tetrafluoroethylene monomer and one or more of vinyl ether monomer, vinyl ester monomer, vinyl alcohol monomer, and allyl alcohol monomer, with a number average molecular weight of 5000 g / mol to 7000 g / mol and a hydroxyl value of 50 mgKOH / g to 70 mgKOH / g.

[0013] The diluent is one or more of butyl acetate, heavy aromatic solvent naphtha, ethylene glycol butyl ether acetate, and propylene glycol diacetate.

[0014] The tear-resistant resin is one or more of 303 polyether, 505 polyether, 604 polyether, polyetheramine T403 or its derivatives, and amino-terminated polyether chain extender. The amino-terminated polyether chain extender has an amino equivalent of 575-625 and a viscosity of 2000-3500 mPa.s at 40° C. The selection range includes Amine-HCA PG-1000 amino-terminated polyether chain extender, Amine-HCAPT-1000, etc.

[0015] The pigment is a mixture of one or two of rutile titanium dioxide and antimony white and carbon black in a ratio of (40-220):1.

[0016] The thixotropic agent is a mixture of fumed silica and organic modified bentonite in a ratio of 1: (3-4).

[0017] The hollow microspheres include one or more of PMMA microspheres, zirconium dioxide microspheres, silicon dioxide microspheres, and organic silicon microspheres. The diameter of the microspheres is 1 μm to 150 μm, and the initial expansion temperature of the microspheres is higher than 75°C.

[0018] The anti-biological attachment agent is an auxiliary agent with outstanding inhibition of the growth of microorganisms and algae in organic media. The selection range of the anti-biological attachment agent includes SY-7603 antibacterial, anti-mildew and anti-algae agent, Hosocide BOD, HosocideDO, Hosocide CCT, Hosocide 678 and the like.

[0019] The polyisocyanate is a solvent-free, non-yellowing polyisocyanate containing two or more NCO groups in its molecular structure, a closed cup flash point of more than 60° C., and includes one or more of HDI biuret, HDI trimer, and low-viscosity prepolymer.

[0020] The HDI biuret has an NCO content of (22-24)%, a viscosity of 1200-3200 mPa.s at 25° C., and a selection range including 24A-100, HB-200, and the like.

[0021] The HDI trimer has an NCO content of (20-24)%, a viscosity of 100-4000 mPa.s at 25° C., and a selection range including TPA-100, TKA-100, TMA-100, TLA-100, TUL-100, HT-100, HT-200, HT-300, HT-400, HT-500, HT-600, etc.

[0022] The low-viscosity prepolymer has an NCO content of (24-28)%, a viscosity of 200-1000 mPa.s at 25° C., and a selection range including HA-252 and IPP-270.

[0023] The high elastic prepolymer refers to a prepolymer or polyisocyanate that contains two or more NCO groups in the molecular structure, has high elasticity, a closed cup flash point of >60°C, is solvent-free and does not yellow, and includes one or more of a difunctional prepolymer and an HDI trimer.

[0024] The difunctional prepolymer contains two NCO groups in each molecular chain, has an NCO content of (11-20)%, and a viscosity of 100-2000 mPa.s at 25° C. The selection range includes AE700-100 difunctional prepolymer, D101 difunctional prepolymer, D201 difunctional prepolymer, A201H difunctional prepolymer, etc.

[0025] The HDI trimer contains three NCO groups in each molecule, with an NCO content of (11-13)%, a viscosity of 1500-1800 mPa.s at 25° C., and the selection range includes TSE-100 trimer and the like.

[0026] The present invention also provides a method for preparing the self-cleaning protective coating, wherein:

[0027] The preparation of component A comprises the following steps:

[0028] The production is carried out using a dispersing and stirring kettle. Solid fluorocarbon resin is added to the diluent, and the mixture is soaked at a material temperature of 60°C to 80°C for at least 2 hours. After the solid fluorocarbon resin is fully swollen, the stirrer is turned on at a stirring speed of 10 rpm to 80 rpm. After stirring at a material temperature of 60°C to 80°C for 3 to 6 hours, liquid fluorocarbon resin, tear-resistant resin, pigment, and thixotropic agent are added. The mixture is first stirred slowly at 15 r / min for 10 minutes, and then the high-speed disperser is turned on at a dispersing speed of 1000 r / min to 1400 r / min and a stirring speed of 40 r / min to 60 r / min. After 40 minutes of dispersion and stirring, the mixture is passed through a nano sand mill to reach fineness, and then hollow microspheres and anti-biological adhesion agents are added at a stirring speed of 40 r / min and a dispersing speed of 600 r / min to 800 r / min. After mixing evenly, the mixture is color-adjusted and packaged.

[0029] The preparation of component B comprises the following steps:

[0030] The components are added into a drying kettle for heating and dissolution, dehydration and mixing, and filled with dry nitrogen or inert gas for protection during packaging.

[0031] Compared with conventional technology, in the present invention, the fluorocarbon resin adopts a solid fluorocarbon resin with a high molecular weight to improve the flexibility and elongation of the material. Tear-resistant resin is introduced to improve tear resistance and elasticity. Hollow microspheres are introduced to improve the problem of increased surface energy caused by reduced fluorine content after adding high-performance resins; hollow microspheres have a low density and are easier to gather on the coating surface than solid microspheres of the same size, thereby improving the contact angle; hollow microspheres are conducive to dispersing the deformation stress of the coating film and improving the ability to resist cracking. All components in component A and component B of the self-cleaning protective coating for concrete surfaces of the present invention are of molecular structure types that are resistant to yellowing and powdering to ensure the long-term color retention of the coating. The flash point of the diluent used is greater than 60°C to improve the safety of the coating when in use. The preparation method of the present invention ensures that the solid fluorocarbon resin can be fully dissolved and fully exert its effect. Lightweight fillers and anti-biological adhesion agents are added after high-speed dispersion and grinding to avoid the destruction of lightweight fillers and anti-biological adhesion agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Contact angle graphs of hollow microspheres before and after coating. DETAILED DESCRIPTION

[0033] Example 1

[0034] Preparation of component A

[0035] Add 90kg butyl acetate, 125kg ethylene glycol butyl ether acetate and 250kg solid fluorocarbon resin into a 1000L dispersing stirring kettle, turn on the heating, soak for 3 hours at a material temperature of 60℃~80℃, let the solid fluorocarbon resin fully swell, turn on the stirrer, and gradually increase the stirring speed from 0 rpm to 70 rpm according to the dissolution situation. After stirring for 4 hours at a material temperature of 60℃~80℃, add 25kg liquid fluorocarbon resin, 10kg polyetheramine T403, 15kg Amine-HCA PG-1000 amino-terminated polyether chain extender, and 15kg Amine-HCA PT-1000 amino-terminated polyether chain extender, 40kg rutile titanium dioxide, 1kg carbon black, 5kg fumed silica, 20kg organic modified bentonite, first slowly stirred at 15r / min for 10 minutes, then turned on the high-speed disperser, the dispersion speed was 1000r / min~1400r / min, the stirring speed was 50r / min, and the dispersion and stirring were carried out for 40 minutes. After the nano sand mill reached the fineness, 100kg silica microspheres and 10kg SY-7603 antibacterial, anti-mildew and anti-algae agent, 1kg Hosocide 678 were added, the stirring speed was 40r / min, the dispersion speed was 600r / min, and the mixture was evenly mixed and then the color was adjusted and packaged.

[0036] Preparation of component B

[0037] 200kg TPA-100 trimer, 125kg HA-252 prepolymer, 30kg AE700-100 difunctional prepolymer, 15kg D201 difunctional prepolymer and 15kg TSE-100 trimer were added into a 500L drying kettle for dehydration and mixing, and filled with dry nitrogen for protection during packaging.

[0038] After component A and component B are evenly mixed at room temperature at a ratio of A / B = 10 / 1 (mass ratio), a film with a thickness of 1 mm ± 0.2 mm is formed by scraping. After curing at 23°C ± 2°C for 14 days, the tensile strength is 12.3 MPa, the elongation at break is 135%, the tear strength is 23.2 kN / m, the contact angle is 121.3°, and the stain resistance is level 0.

[0039] Example 2

[0040] Preparation of component A

[0041] 175kg of heavy aromatic solvent naphtha and 225kg of solid fluorocarbon resin were added to a 1000L dispersing stirring kettle, and the heating was turned on. After soaking for 2.5 hours at a material temperature of 60℃~80℃, the solid fluorocarbon resin was fully swollen, and then the stirrer was turned on. According to the dissolution situation, the stirring speed was gradually increased from 0 rpm to 60 rpm. After stirring for 3.5 hours at a material temperature of 60℃~80℃, 50kg of liquid fluorocarbon resin, 10kg of 604 polyether, 15kg of Amine-HCAPG-1000 amino-terminated polyether chain extender, and 15kg of Amine-HCA were added. PT-1000 amino-terminated polyether chain extender, 60kg antimony white, 0.5kg carbon black, 7.5kg fumed silica, 22.5kg organic modified bentonite, first slowly stirred at 15r / min for 10 minutes, then turned on the high-speed disperser, the dispersion speed was 1000r / min~1400r / min, the stirring speed was 55r / min, and the dispersion and stirring were carried out for 40 minutes. After the sand mill reached the fineness, 75kg silica microspheres and 7.5kg Hosocide BOD, 2.5kg Hosocide DO, 1.5kg Hosocide CCT were added, the stirring speed was 40r / min, the dispersion speed was 650r / min, and the mixture was evenly mixed and packaged.

[0042] Preparation of component B

[0043] 40kg HB-200 biuret, 160kg HT-100 trimer, 100kg HA-252 prepolymer, 60kg AE700-100 difunctional prepolymer, 12kg D201 difunctional prepolymer and 20kg TSE-100 trimer were added into a 500L drying kettle for dehydration and mixing, and dry nitrogen was used for protection during packaging.

[0044] After the A component and the B component were mixed evenly at room temperature according to A / B=100 / 11 (mass ratio), a film with a thickness of 1mm±0.2mm was formed by scraping. After curing at 23℃±2℃ for 14 days, the tensile strength was 10.9MPa, the elongation at break was 82%, the tear strength was 21.1kN / m, and the contact angle was 108.3°( Figure 1 ), stain resistance level 0.

[0045] Example 3

[0046] Preparation of component A

[0047] Add 50kg butyl acetate, 125kg propylene glycol diacetate and 200kg solid fluorocarbon resin into a 1000L dispersing stirring kettle, turn on the heating, soak for 2.5 hours at a material temperature of 60℃~80℃, let the solid fluorocarbon resin fully swell, turn on the stirrer, and gradually increase the stirring speed from 0 rpm to 50 rpm according to the dissolution situation. After stirring for 3 hours at a material temperature of 60℃~80℃, add 50kg liquid fluorocarbon resin, 20kg 505 polyether, 5kg polyetheramine T403, 25kgAmine-HCAPG-1000 amino-terminated polyether chain extender, 60kg rutile titanium dioxide, 0.5kg carbon black, 7.5kg fumed silica, 22.5kg organic modified bentonite, first slowly stirred at 15r / min for 10 minutes, then turned on the high-speed disperser, the dispersion speed was 1000r / min~1400r / min, the stirring speed was 45r / min, and the dispersion and stirring were carried out for 40 minutes. After the nano sand mill reached the fineness, 60kg PMMA microspheres, 15kg zirconium dioxide microspheres, 15kg silicon dioxide microspheres and 8kg Hosocide DO were added, the stirring speed was 40r / min, the dispersion speed was 700r / min, and the color was adjusted and packaged after mixing evenly.

[0048] Preparation of component B

[0049] 160kg HB-200 biuret, 80kg HT-300 trimer, 100kg IPP-270 prepolymer, 60kg D101 difunctional prepolymer and 52kg A201H difunctional prepolymer were added into a 500L drying kettle for dehydration and mixing, and filled with dry nitrogen for protection during packaging.

[0050] After component A and component B are evenly mixed at room temperature at a ratio of A / B = 100 / 13.5 (mass ratio), a film with a thickness of 1 mm ± 0.2 mm is formed by scraping. After curing at 23°C ± 2°C for 14 days, the tensile strength is 14.7 MPa, the elongation at break is 181%, the tear strength is 35.3 kN / m, the contact angle is 105.6°, and the stain resistance is level 0.

[0051] Example 4

[0052] Preparation of component A

[0053] Add 65kg butyl acetate, 100kg propylene glycol diacetate and 200kg solid fluorocarbon resin into a 1000L dispersing stirring kettle, turn on the heating, soak for 3 hours at a material temperature of 60℃~80℃, let the solid fluorocarbon resin fully swell, turn on the stirrer, and gradually increase the stirring speed from 0 rpm to 50 rpm according to the dissolution situation. After stirring for 5 hours at a material temperature of 60℃~80℃, add 60kg liquid fluorocarbon resin, 25kg 303 polyether, 10kg 604 polyether, 10kgAmine-HCAPT-1000 amino-terminated polyether chain extender, 40kg antimony white, 0.5kg carbon black, 10kg fumed silica, 30kg organic modified bentonite, first slowly stirred at 15r / min for 10 minutes, then turned on the high-speed disperser, the dispersion speed was 1000r / min~1400r / min, the stirring speed was 50r / min, and the dispersion and stirring were carried out for 40 minutes. After the nano sand mill reached the fineness, 35kgPMMA microspheres, 60kg silicone microspheres and 5kg Hosocide CCT were added, the stirring speed was 40r / min, the dispersion speed was 800r / min, and the color was adjusted and packaged after mixing evenly.

[0054] Preparation of component B

[0055] 160kg 24A-100 biuret, 80kg TLA-100 trimer, 100kg HA-252 prepolymer, 40kg D101 difunctional prepolymer and 80kg D201 difunctional prepolymer were added into a 500L drying kettle for dehydration and mixing, and filled with dry nitrogen for protection during packaging.

[0056] After component A and component B are evenly mixed at room temperature at a ratio of A / B=100 / 17 (mass ratio), a film with a thickness of 1mm±0.2mm is formed by scraping. After curing at 23℃±2℃ for 14 days, the tensile strength is 12.7MPa, the elongation at break is 112%, the tear strength is 31.2kN / m, the contact angle is 113.6°, and the stain resistance is level 0.

[0057] Experiments have shown that when the contact angle of the coating surface of the self-cleaning protective coating prepared in Examples 1-4 of the present invention reaches 90° or more, the stain resistance result measured according to the GB / T 9780-2013 test method for stain resistance of architectural coatings can reach level 0, that is, the level of no pollution, indicating that under the pollution degree and flushing conditions specified in the test method, the pollutants attached to the surface of the coating can be easily washed away by water, and it has a good self-cleaning effect. Continuing to increase the contact angle is conducive to improving the stain resistance performance of the coating when facing complex pollution degrees and flushing conditions in the natural environment. Figure 1The photo shows that the contact angle increases by nearly 20 degrees after adding microspheres. If the contact angle of the film-forming material is adjusted to 120°, and the type, gradation and concentration of the hollow microspheres in the coating are adjusted so that the microspheres can build more perfect protrusions on the surface of the cured coating, and with the help of nano-scale fillers such as fumed silica, it is expected to achieve a super-hydrophobic coating with a contact angle of more than 150°.

[0058] The following table is a summary table of experimental data of Examples 1-4.

[0059]

[0060]

Claims

1. A self-cleaning protective coating, consisting of component A and component B, characterized in that: Component A and component B are mixed at a mass ratio of A / B = 100 / (5-20) at room temperature; In parts by mass, component A comprises: 40-60 parts of fluorocarbon resin, 30-45 parts of diluent, 12-20 parts of tear-resistant resin, 13-18 parts of pigment, 2-10 parts of thixotropic agent, 10-20 parts of hollow microspheres, and 0.1-2.5 parts of anti-biological attachment agent; By mass, component B: 65-90 parts of polyisocyanate, 10-35 parts of high elastic prepolymer; The fluorocarbon resin is a mixture of solid fluorocarbon resin and liquid fluorocarbon resin in a ratio of 1: (0.1-0.4).

2. A self-cleaning protective coating as claimed in claim 1, characterized in that: The solid fluorocarbon resin refers to an alternating copolymer or graft copolymer of one or both of trifluorochloroethylene monomer or tetrafluoroethylene monomer and one or more of vinyl ether monomer, vinyl ester monomer, vinyl alcohol monomer, and allyl alcohol monomer, with a number average molecular weight of 13000 g / mol to 22000 g / mol and a hydroxyl value of 40 mgKOH / g to 60 mgKOH / g; The liquid fluorocarbon resin refers to an alternating copolymer or graft copolymer of one or two of trifluorochloroethylene monomer or tetrafluoroethylene monomer and one or more of vinyl ether monomer, vinyl ester monomer, vinyl alcohol monomer, and allyl alcohol monomer, with a number average molecular weight of 5000 g / mol to 7000 g / mol and a hydroxyl value of 50 mgKOH / g to 70 mgKOH / g.

3. A self-cleaning protective coating as claimed in claim 1, characterized in that: The tear-resistant resin is one or more of 303 polyether, 505 polyether, 604 polyether, polyetheramine T403 or its derivatives, and amino-terminated polyether chain extender; The amino-terminated polyether chain extender has an amino equivalent of 575-625 and a viscosity of 2000-3500 mPa.s at 40° C. The selection range includes Amine-HCA PG-1000 and Amine-HCA PT-1000.

4. A self-cleaning protective coating as claimed in claim 1, characterized in that: The thixotropic agent is a mixture of fumed silica and organic modified bentonite in a ratio of 1: (3-4).

5. A self-cleaning protective coating as claimed in claim 1, characterized in that: The hollow microspheres include one or more of PMMA microspheres, zirconium dioxide microspheres, silicon dioxide microspheres, and organic silicon microspheres. The diameter of the microspheres is 1 μm to 150 μm, and the initial expansion temperature of the microspheres is higher than 75°C.

6. A self-cleaning protective coating as claimed in claim 1, characterized in that: The anti-biological attachment agent is an auxiliary agent having an outstanding ability to inhibit the growth of microorganisms and algae in an organic medium.

7. A self-cleaning protective coating as claimed in claim 6, characterized in that: The selection range of the anti-biological attachment agent includes SY-7603 antibacterial, anti-mildew and anti-algae agent, Hosocide BOD, Hosocide DO, Hosocide CCT and Hosocide678.

8. A self-cleaning protective coating as claimed in claim 1, characterized in that: The polyisocyanate is a solvent-free, non-yellowing polyisocyanate containing two or more NCO groups in its molecular structure, a closed cup flash point of >60°C, and includes one or more of HDI biuret, HDI trimer, and low-viscosity prepolymer; The HDI biuret has an NCO content of (22-24)%, a viscosity of 1200-3200 mPa.s at 25°C, and a selection range of 24A-100 and HB-200; The HDI trimer has an NCO content of (20-24)%, a viscosity of 100-4000 mPa.s at 25° C., and the selection range includes TPA-100, TKA-100, TMA-100, TLA-100, TUL-100, HT-100, HT-200, HT-300, HT-400, HT-500, and HT-600; The low-viscosity prepolymer has an NCO content of (24-28)%, a viscosity of 200-1000 mPa.s at 25° C., and a selection range including HA-252 and IPP-270.

9. A self-cleaning protective coating as claimed in claim 1, characterized in that: The highly elastic prepolymer refers to a prepolymer or polyisocyanate that contains two or more NCO groups in the molecular structure, has high elasticity, a closed cup flash point of >60°C, does not contain solvent and does not yellow, including one or more of a difunctional prepolymer and an HDI trimer; The difunctional prepolymer contains two NCO groups in each molecular chain, has an NCO content of (11-20)%, and a viscosity of 100-2000 mPa.s at 25° C. The selection range includes AE700-100 difunctional prepolymer, D101 difunctional prepolymer, D201 difunctional prepolymer, and A201H difunctional prepolymer; The HDI trimer contains three NCO groups in each molecule, with an NCO content of (11-13)%, a viscosity of 1500-1800 mPa.s at 25° C., and the selection range includes TSE-100 trimer.

10. The method for preparing the self-cleaning protective coating according to claim 1, characterized in that: The preparation of component A comprises the following steps: The production is carried out using a dispersing and stirring kettle. Solid fluorocarbon resin is added to the diluent, and the mixture is soaked at a material temperature of 60°C to 80°C for at least 2 hours. After the solid fluorocarbon resin is fully swollen, the stirrer is turned on at a stirring speed of 10 rpm to 80 rpm. After stirring at a material temperature of 60°C to 80°C for 3 to 6 hours, liquid fluorocarbon resin, tear-resistant resin, pigment, and thixotropic agent are added. The mixture is first stirred slowly at 15 r / min for 10 minutes, and then the high-speed disperser is turned on at a dispersing speed of 1000 r / min to 1400 r / min and a stirring speed of 40 r / min to 60 r / min. After 40 minutes of dispersion and stirring, the mixture is passed through a nano sand mill to reach fineness, and then hollow microspheres and anti-biological adhesion agents are added at a stirring speed of 40 r / min and a dispersing speed of 600 r / min to 800 r / min. After mixing evenly, the mixture is color-adjusted and packaged. The preparation of component B comprises the following steps: The components are added into a drying kettle for heating and dissolution, dehydration and mixing, and filled with dry nitrogen or inert gas for protection during packaging.

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