Weather-resistant anti-corrosion polyurea coating as well as preparation method and application thereof

Abstract

The invention discloses a weather-resistant anti-corrosion polyurea coating as well as a preparation method and application thereof. The weather-resistant anti-corrosion polyurea coating comprises a component A and a component B, wherein the component A comprises the following components in percentage by mass: 60-75% of polyaspartic acid ester resin; 10%-15% of a light stabilizer-fluorocarbon chain modified nano silicon dioxide; 15%-25% of a diluent, and the component B comprises a hexamethylene diisocyanate isocyanurate tripolymer. The preparation method of the weather-resistant anti-corrosion polyurea coating comprises the following steps: firstly, respectively preparing the component A and the component B, and then uniformly mixing the component A and the component B. The weather-resistant and corrosion-resistant polyurea coating is long in activation period and simple in construction equipment, a formed paint film is high in hydrophobicity, good in flexibility, excellent in mechanical property, excellent in weather resistance and excellent in corrosion resistance, long-acting protection can be provided for outdoor steel structures, and the weather-resistant and corrosion-resistant polyurea coating is suitable for large-scale industrial production and application.

Description

Technical Field

[0001] This invention relates to the field of metal corrosion protection technology, specifically to a weather-resistant and corrosion-resistant polyurea coating, its preparation method, and its application. Background Technology

[0002] Steel structures, composed of steel materials, are one of the main types of building structures. Long-term exposure to outdoor environments, particularly to temperature and humidity, makes steel structures susceptible to corrosion. This not only severely impacts their lifespan and personal safety but also leads to resource waste and environmental pollution. Polyurea coatings are unique and high-performance coating materials suitable for steel structure corrosion protection. However, existing polyurea coatings generally suffer from problems such as excessively fast curing speeds, demanding application equipment requirements, and the resulting film's weather resistance, corrosion resistance, and resistance to various media cannot fully meet the increasing demands of practical applications, thus failing to provide adequate long-term protection for steel structures.

[0003] Therefore, developing a polyurea coating with good construction performance and excellent weather resistance and corrosion resistance of the resulting paint film is of great significance for achieving long-term protection of outdoor steel structures. Summary of the Invention

[0004] The purpose of this invention is to provide a weather-resistant and corrosion-resistant polyurea coating, its preparation method, and its application.

[0005] The technical solution adopted in this invention is: A weather-resistant and corrosion-resistant polyurea coating, comprising component A and component B; Component A comprises the following components by mass percentage: Polyaspartic acid ester resin: 60%–75%; Light stabilizer - fluorocarbon chain modified nano-silica: 10%–15%; Diluent: 15%–25%; Component B includes hexamethylene diisocyanate isocyanurate trimer.

[0006] Preferably, the light stabilizer-fluorocarbon chain modified nano-silica is prepared by a method comprising the following steps: a) Mix aliphatic isocyanate and fluorinated monohydric alcohol, and then carry out an addition reaction under a protective atmosphere to obtain fluorinated isocyanate; b) Disperse nano-silica in a solvent, then add a hindered amine light stabilizer containing polyfunctional amino groups and a silane coupling agent containing isocyanate groups to modify the surface of nano-silica, then add fluorinated isocyanate to carry out an addition reaction, and then separate, purify and dry the product to obtain light stabilizer-fluorocarbon chain modified nano-silica.

[0007] Preferably, the molar ratio of the aliphatic isocyanate and the fluorinated monohydric alcohol in step a) is 1:0.9 to 1.0.

[0008] Preferably, the aliphatic isocyanate in step a) is at least one of 4,4-diisocyanate dicyclohexylmethane (HMDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HDI).

[0009] Preferably, the fluorinated monohydric alcohol in step a) is at least one of 4,4,5,5,6,6,7,7,7-nonafluoro-1-heptanol, 1H,1H,2H,2H-perfluoro-1-decanol, 1H,1H,2H,2H-perfluorooctanol, 3-perfluorohexylpropanol, 3-perfluorooctylpropanol, and 1H,1H,2H,2H-perfluorohexyl-1-ol.

[0010] Preferably, the protective atmosphere in step a) is a nitrogen atmosphere.

[0011] Preferably, the addition reaction in step a) is carried out at a temperature of 75°C to 100°C for a reaction time of 3 to 6 hours.

[0012] Preferably, the particle size of the nano-silica in step b) is 10 nm to 60 nm.

[0013] Preferably, the dispersion method in step b) is ultrasonic dispersion, and the ultrasonic dispersion time is 1h to 2h.

[0014] Preferably, the solvent in step b) is at least one of toluene and xylene.

[0015] Preferably, the hindered amine light stabilizer containing polyfunctional amino groups in step b) is hindered amine light stabilizer HS-944.

[0016] Preferably, the silane coupling agent containing isocyanate groups in step b) is at least one of 3-isocyanatopropyltrimethoxysilane and propyltriethoxysilane.

[0017] Preferably, the surface modification in step b) is carried out at a temperature of 80℃ to 110℃ for a reaction time of 3h to 6h.

[0018] Preferably, the addition reaction in step b) is carried out at a temperature of 40°C to 60°C for a reaction time of 1 to 3 hours.

[0019] Preferably, the product separation, purification and drying in step b) includes the following operations: centrifuging the reaction solution, washing the solid with anhydrous ethanol, and then drying.

[0020] Preferably, the diluent is at least one of tetrahydrofuran and butyl acetate.

[0021] Preferably, the hexamethylene diisocyanate isocyanurate trimer is at least one of Asahi Kasei's TLA-100 and Asahi Kasei's TUL-100.

[0022] A method for preparing a weather-resistant and corrosion-resistant polyurea coating as described above includes the following steps: 1) Preparation of components A and B: Preparation of component A: Weigh out polyaspartic acid ester resin, light stabilizer-fluorocarbon chain modified nano silica and diluent, mix them evenly to obtain component A; Preparation of component B: Weigh out hexamethylene diisocyanate isocyanurate trimer according to an NCO index of 1.05 to 1.15 to obtain component B; 2) Mix component A and component B evenly to obtain a weather-resistant and corrosion-resistant polyurea coating.

[0023] A weather-resistant and corrosion-resistant polyurea coating as described above is used for corrosion protection of steel structures.

[0024] The beneficial effects of this invention are: the weather-resistant and corrosion-resistant polyurea coating of this invention has a long activation period, simple construction equipment, and the formed paint film has strong hydrophobicity, good flexibility, excellent mechanical properties, excellent weather resistance, and excellent corrosion resistance. It can provide long-term protection for outdoor steel structures and is suitable for large-scale industrial production and application.

[0025] Specifically: 1) The film-forming material in the weather-resistant and corrosion-resistant polyurea coating of the present invention is a trimer of polyaspartic acid ester resin and hexamethylene diisocyanate isocyanurate. The coating has a long activation period and can be applied using conventional construction equipment. 2) The weather-resistant and corrosion-resistant polyurea coating of the present invention contains light stabilizer-fluorocarbon chain modified nano-silica, which can form chemical bonds with the film-forming material, which is beneficial to the dispersion of nano-silica in the system. In addition, the light stabilizer grafted onto the nano-silica can improve the weather resistance of the coating film, and the fluorocarbon chain can improve the surface hydrophobicity of the coating film, thereby improving the coating film's resistance to media penetration (salt spray resistance, acid and alkali resistance), and ultimately enhancing the corrosion resistance of the coating film. 3) The weather-resistant and corrosion-resistant polyurea coating of the present invention can provide long-term protection for outdoor steel structures (e.g., for the outer wall protection of oil and gas pipelines and petrochemical storage tanks). The coating film has a long service life, saves resources, reduces environmental pollution, and is suitable for large-scale industrial production and application. Attached Figure Description

[0026] Figure 1 This is a SEM image of the nano-silica from Example 1.

[0027] Figure 2 This is a SEM image of the light stabilizer-fluorocarbon chain modified nano-silica in Example 1.

[0028] Figure 3 This is an XPS image of the nano-silica in Example 1.

[0029] Figure 4 XPS image of nano-silica modified with light stabilizer-fluorocarbon chain in Example 1.

[0030] Figure 5 This is a water contact angle test diagram of the nano-silica in Example 1.

[0031] Figure 6 This is a water contact angle test diagram of the light stabilizer-fluorocarbon chain modified nano-silica in Example 1.

[0032] Figure 7 The image shows the FTIR spectrum of the nano-silica in Example 1.

[0033] Figure 8 The image shows the FTIR spectrum of the light stabilizer-fluorocarbon chain modified nano-silica in Example 1. Detailed Implementation

[0034] The present invention will be further explained and described below with reference to specific embodiments.

[0035] Example 1: A light stabilizer-fluorocarbon chain modified nano-silica, the preparation method of which is as follows: a) Isophorone diisocyanate (IPDI) and 1H,1H,2H,2H-perfluorooctanol were dehydrated under vacuum. Then, 32.3g of IPDI and 52.8g of 1H,1H,2H,2H-perfluorooctanol were added to a three-necked flask equipped with a cooling water circulation device. The flask was then evacuated and N2 was introduced using a Schlenk double-row tube for 5 minutes each, and the cycle was repeated three times. The temperature was then raised to 85℃ and reacted for 5 hours. N2 was introduced throughout the reaction to obtain fluorinated isophorone diisocyanate. b) Add 4.5g of nano-silica (particle size 20nm±5nm) to 150g of toluene, ultrasonically disperse for 1h, then add 65g of hindered amine light stabilizer HS-944, stir evenly, then add 7.5g of 3-isocyanate-propyltrimethoxysilane, heat to 100℃ and react for 4h, then cool to 50℃, then add 20.5g of fluorinated isophorone diisocyanate, continue to react for 2h, then cool to room temperature, then centrifuge at 10000rpm for 10min, take the solid, wash with anhydrous ethanol and centrifuge 3 times, then put it in an oven and bake at 60℃ for 24h to obtain light stabilizer-fluorocarbon chain modified nano-silica.

[0036] Performance testing: 1) The scanning electron microscope (SEM) image of the nano-silica in this embodiment is shown below. Figure 1 As shown, the SEM image of the light stabilizer-fluorocarbon chain modified nano-silica is as follows. Figure 2 As shown.

[0037] Depend on Figure 1 and Figure 2 It can be seen that unmodified nano-silica exhibits significant agglomeration, while the agglomeration of light stabilizer-fluorocarbon chain modified silica is significantly reduced.

[0038] 2) The X-ray photoelectron spectroscopy (XPS) pattern of the nano-silica in this embodiment is shown below. Figure 3 As shown, the XPS plot of light stabilizer-fluorocarbon chain modified nano-silica is as follows. Figure 4 As shown.

[0039] Depend on Figure 3 and Figure 4 It can be seen that peaks of F and N elements appeared on the surface of nano-silica modified by light stabilizer-fluorocarbon chain, indicating that nano-silica was successfully modified by light stabilizer-fluorocarbon chain.

[0040] 3) The water contact angle test diagram of the nano-silica in this embodiment is shown below. Figure 5 As shown in the figure, the water contact angle test diagram of light stabilizer-fluorocarbon chain modified nano-silica is as follows. Figure 6 As shown.

[0041] Depend on Figure 5 and Figure 6 It can be seen that the water contact angle of unmodified nano-silica is much less than 90°, indicating strong hydrophilicity, while the water contact angle of nano-silica modified by light stabilizer-fluorocarbon chain is 142°, indicating strong hydrophobicity. This shows that nano-silica was successfully modified by light stabilizer-fluorocarbon chain.

[0042] 4) The Fourier transform infrared (FTIR) spectrum of the nano-silica in this embodiment is shown below. Figure 7As shown, the FTIR spectrum of light stabilizer-fluorocarbon chain modified nano-silica is as follows. Figure 8 As shown.

[0043] Depend on Figure 7 and Figure 8 It can be seen that in the infrared spectrum of nano-silica, 3466 cm⁻¹ -1 The absorption peak at 3632.0 cm⁻¹ is the stretching vibration peak of Si-OH. -1 and 1637.6cm -1 The absorption peak at 1107 cm⁻¹ represents the symmetric stretching and asymmetric vibrations of water molecules (surface adsorbed water and structural water), as well as the bending vibrations of adsorbed water. -1 and 472cm -1 The absorption peaks at 806 cm⁻¹ correspond to the tensile and bending vibrations of Si-O-Si, respectively. -1 The absorption peak at 2900 cm⁻¹ is attributed to the vibration of Si-O; in the infrared spectrum of light stabilizer-fluorocarbon chain modified nano-silica, the peak at 2900 cm⁻¹ is... -1 The nearby absorption peak is the stretching vibration peak of -CH2 and -CH3 in the system, at 1735.9 cm⁻¹. -1 The peak at 1641.4 cm⁻¹ represents the stretching vibration of the C=O group in the ester group. -1 The peak at 1570.1 cm⁻¹ represents the stretching vibration of the C=O group of the urea group. -1 and 1533.4cm -1 The absorption peak at 1483.3 cm⁻¹ represents the C atom of the triazine ring and the N atom of the piperazine ring. -1 and 1427.3cm -1 The peak at this point represents the skeletal vibration peak of C=N on the triazine ring; it is evident that nano-silica was successfully modified by the light stabilizer-fluorocarbon chain.

[0044] In summary, this embodiment has indeed successfully prepared light stabilizer-fluorocarbon chain modified nano-silica.

[0045] A weather-resistant and corrosion-resistant polyurea coating, the preparation method of which is as follows: 1) Preparation of components A and B: Preparation of component A: 26.5g of polyaspartic acid ester resin F520 (Shenzhen Feiyang Junyan New Material Co., Ltd.), 5g of the light stabilizer-fluorocarbon chain modified nano silica in this example, and 7g of butyl acetate were mixed and ultrasonically dispersed for 1.5h to obtain component A. Preparation of component B: Weigh 17.5g of hexamethylene diisocyanate isocyanurate trimer (Asahi Kasei TLA-100) according to an NCO index of 1.06 to obtain component B; 2) Mix component A and component B evenly to obtain a weather-resistant and corrosion-resistant polyurea coating.

[0046] Example 2: A light stabilizer-fluorocarbon chain modified nano-silica, the preparation method of which is as follows: a) IPDI and 3-perfluorooctylpropanol were dehydrated under vacuum. Then, 32.3 g of IPDI and 69.4 g of 3-perfluorooctylpropanol were added to a three-necked flask equipped with a cooling water circulation device. The flask was then evacuated and purged with N2 using a Schlenk double-row tube for 5 min each, and the cycle was repeated three times. The temperature was then raised to 85 °C and reacted for 5 h. N2 was purged throughout the reaction to obtain fluorinated isophorone diisocyanate. b) Add 4.5g of nano-silica (particle size 20nm±5nm) to 150g of toluene, ultrasonically disperse for 1h, then add 65g of hindered amine light stabilizer HS-944, stir evenly, then add 7.5g of 3-isocyanate-propyltrimethoxysilane, heat to 100℃ and react for 4h, then cool to 50℃, then add 24.5g of fluorinated isophorone diisocyanate, continue to react for 2h, then cool to room temperature, then centrifuge at 10000rpm for 10min, take the solid, wash with anhydrous ethanol and centrifuge 3 times, then put it in an oven and bake at 60℃ for 24h to obtain light stabilizer-fluorocarbon chain modified nano-silica.

[0047] Tests (using the same method as in Example 1) confirmed that this example successfully prepared light stabilizer-fluorocarbon chain modified nano-silica.

[0048] A weather-resistant and corrosion-resistant polyurea coating, the preparation method of which is as follows: 1) Preparation of components A and B: Preparation of component A: 26.5g of polyaspartic acid ester resin F520 (Shenzhen Feiyang Junyan New Material Co., Ltd.), 5g of the light stabilizer-fluorocarbon chain modified nano silica in this example, and 7g of butyl acetate were mixed and ultrasonically dispersed for 1h to obtain component A. Preparation of Component B: Weigh 25g of hexamethylene diisocyanate isocyanurate trimer (Asahi Kasei TUL-100) according to an NCO index of 1.07 to obtain Component B; 2) Mix component A and component B evenly to obtain a weather-resistant and corrosion-resistant polyurea coating.

[0049] Example 3: A light stabilizer-fluorocarbon chain modified nano-silica, the preparation method of which is as follows: a) IPDI and nonafluoro-1-heptanol were dehydrated under vacuum. Then, 32.3 g of IPDI and 40.32 g of 4,4,5,5,6,6,7,7,7-nonafluoro-1-heptanol were added to a three-necked flask equipped with a cooling water circulation device. The flask was then evacuated and purged with N2 using a Schlenk double-row tube for 5 min each, and the cycle was repeated three times. The temperature was then raised to 85 °C and reacted for 5 h. N2 was purged throughout the reaction to obtain fluorinated isophorone diisocyanate. b) Add 4.5g of nano-silica (particle size 20nm±5nm) to 150g of toluene, ultrasonically disperse for 1h, then add 65g of hindered amine light stabilizer HS-944, stir evenly, then add 7.5g of 3-isocyanate-propyltrimethoxysilane, heat to 100℃ and react for 4h, then cool to 50℃, then add 17.5g of fluorinated isophorone diisocyanate, continue to react for 2h, then cool to room temperature, then centrifuge at 10000rpm for 10min, take the solid, wash with anhydrous ethanol and centrifuge 3 times, then put it in an oven and bake at 60℃ for 24h to obtain light stabilizer-fluorocarbon chain modified nano-silica.

[0050] Tests (using the same method as in Example 1) confirmed that this example successfully prepared light stabilizer-fluorocarbon chain modified nano-silica.

[0051] A weather-resistant and corrosion-resistant polyurea coating, the preparation method of which is as follows: 1) Preparation of components A and B: Preparation of component A: 26.5g of polyaspartic acid ester resin F520 (Shenzhen Feiyang Junyan New Material Co., Ltd.), 5g of the light stabilizer-fluorocarbon chain modified nano silica in this example, and 7g of butyl acetate were mixed and ultrasonically dispersed for 1h to obtain component A. Preparation of component B: Weigh 17.5g of hexamethylene diisocyanate isocyanurate trimer (Asahi Kasei TLA-100) according to an NCO index of 1.06 to obtain component B; 2) Mix component A and component B evenly to obtain a weather-resistant and corrosion-resistant polyurea coating.

[0052] Example 4: A light stabilizer-fluorocarbon chain modified nano-silica, the preparation method of which is as follows: a) Hexamethylene diisocyanate (HDI) and 1H,1H,2H,2H-perfluorohexane-1-ol were dehydrated under vacuum. Then, 24.3 g of HDI and 38.0 g of 3-perfluorooctylpropanol were added to a three-necked flask equipped with a condenser and water circulation system. The flask was then evacuated and purged with N2 using a Schlenk double-row tube for 5 min each, and the cycle was repeated three times. The temperature was then raised to 85 °C and reacted for 5 h. N2 was purged throughout the reaction to obtain fluorinated hexamethylene diisocyanate. b) Add 4.5g of nano-silica (particle size 20nm±5nm) to 150g of toluene and ultrasonically disperse for 1h. Then add 65g of hindered amine light stabilizer HS-944 and stir evenly. Then add 7.5g of 3-isocyanate-propyltrimethoxysilane and heat to 100℃ for 4h. Then cool to 50℃ and add 15.1g of fluorinated hexamethylene diisocyanate. Continue to react for 2h and then cool to room temperature. Centrifuge at 10000rpm for 10min. Take the solid and wash it with anhydrous ethanol and centrifuge 3 times. Then bake it in an oven at 60℃ for 24h to obtain light stabilizer-fluorocarbon chain modified nano-silica.

[0053] Tests (using the same method as in Example 1) confirmed that this example successfully prepared light stabilizer-fluorocarbon chain modified nano-silica.

[0054] A weather-resistant and corrosion-resistant polyurea coating, the preparation method of which is as follows: 1) Preparation of components A and B: Preparation of component A: 26.5g of polyaspartic acid ester resin F520 (Shenzhen Feiyang Junyan New Material Co., Ltd.), 5g of the light stabilizer-fluorocarbon chain modified nano silica in this example, and 7g of butyl acetate were mixed and ultrasonically dispersed for 1h to obtain component A. Preparation of component B: Weigh 17.5g of hexamethylene diisocyanate isocyanurate trimer (Asahi Kasei TLA-100) according to an NCO index of 1.06 to obtain component B; 2) Mix component A and component B evenly to obtain a weather-resistant and corrosion-resistant polyurea coating.

[0055] Example 5: A light stabilizer-fluorocarbon chain modified nano-silica, the preparation method of which is as follows: a) 4,4-diisocyanate dicyclohexylmethane (HMDI) and 3-perfluorohexylpropanol were dehydrated under vacuum. Then, 37.8 g of HMDI and 54.4 g of 3-perfluorohexylpropanol were added to a three-necked flask equipped with a cooling water circulation device. The flask was then evacuated and purged with N2 using a Schlenk double-row tube for 5 min each, and the cycle was repeated three times. The temperature was then raised to 85 °C and reacted for 5 h. N2 was purged throughout the reaction to obtain fluorinated 4,4-diisocyanate dicyclohexylmethane. b) Add 4.5g of nano-silica (particle size 20nm±5nm) to 150g of toluene, ultrasonically disperse for 1h, then add 65g of hindered amine light stabilizer HS-944, stir evenly, then add 7.5g of 3-isocyanate-propyltrimethoxysilane, heat to 100℃ and react for 4h, then cool to 50℃, then add 22.4g of fluorinated 4,4-diisocyanate dicyclohexylmethane, continue to react for 2h, then cool to room temperature, then centrifuge at 10000rpm for 10min, take the solid, wash with anhydrous ethanol and centrifuge 3 times, then put it in an oven and bake at 60℃ for 24h to obtain light stabilizer-fluorocarbon chain modified nano-silica.

[0056] Tests (using the same method as in Example 1) confirmed that this example successfully prepared light stabilizer-fluorocarbon chain modified nano-silica.

[0057] A weather-resistant and corrosion-resistant polyurea coating, the preparation method of which is as follows: 1) Preparation of components A and B: Preparation of component A: 26.5g of polyaspartic acid ester resin F520 (Shenzhen Feiyang Junyan New Material Co., Ltd.), 5g of the light stabilizer-fluorocarbon chain modified nano silica in this example, and 7g of butyl acetate were mixed and ultrasonically dispersed for 1h to obtain component A. Preparation of component B: Weigh 17.5g of hexamethylene diisocyanate isocyanurate trimer (Asahi Kasei TLA-100) according to an NCO index of 1.06 to obtain component B; 2) Mix component A and component B evenly to obtain a weather-resistant and corrosion-resistant polyurea coating.

[0058] Comparative Example 1: A polyurea coating, the preparation method of which is as follows: 1) Preparation of components A and B: Preparation of component A: Mix 26.5g of polyaspartic acid ester resin F520 (Shenzhen Feiyang Junyan New Material Co., Ltd.) and 7g of butyl acetate, and stir evenly at room temperature to obtain component A; Preparation of component B: Weigh 17.5g of hexamethylene diisocyanate isocyanurate trimer (Asahi Kasei TLA-100) according to an NCO index of 1.06 to obtain component B; 2) Mix component A and component B evenly to obtain polyurea coating.

[0059] Comparative Example 2: A polyurea coating, the preparation method of which is as follows: 1) Preparation of components A and B: Preparation of component A: Mix 26.5g of polyaspartic acid ester resin F520 (Shenzhen Feiyang Junyan New Material Co., Ltd.), 5g of nano silica (particle size 20nm±5nm) and 7g of butyl acetate, and ultrasonically disperse for 1h to obtain component A. Preparation of component B: Weigh 17.5g of hexamethylene diisocyanate isocyanurate trimer (Asahi Kasei TLA-100) according to an NCO index of 1.06 to obtain component B; 2) Mix component A and component B evenly to obtain polyurea coating.

[0060] Performance testing: The weather-resistant and corrosion-resistant polyurea coatings of Examples 1-5 and the polyurea coatings of Comparative Examples 1-2 were sprayed onto steel plates, then cured to form a polyurea film. The performance of the polyurea film was then tested, and the test results are shown in the table below: Table 1 Performance test results of polyurea coating film

[0061] Note: Neutral salt spray: The test was conducted in accordance with "GB / T 1771-2007 Determination of resistance to neutral salt spray of paints and varnishes".

[0062] Ultraviolet aging: The test was conducted according to Method B of 8.2.2 in "GB / T 23987-2009 Artificial weathering exposure of paint and varnish coatings to fluorescent ultraviolet light and water".

[0063] Acid resistance: Tested according to Method A in "GB / T 9274-1988 Determination of resistance to liquid media for paints and varnishes".

[0064] Alkali resistance: Tested according to Method A in "GB / T 9274-1988 Determination of resistance to liquid media for paints and varnishes".

[0065] As shown in Table 1: 1) The weather-resistant and corrosion-resistant polyurea coatings of Examples 1 to 5 have excellent corrosion resistance, weather resistance and media resistance, and are suitable for the protection of steel substrate surfaces, extending the service life of steel structures and saving resources; 2) The anti-corrosion, weather resistance, and media resistance of the polyurea coatings (containing light stabilizer-fluorocarbon chain modified nano-silica) formed in Examples 1-5 are significantly higher than those formed in Comparative Examples 1-2. This indicates that nano-silica containing light stabilizer-fluorocarbon chain modified nano-silica can significantly improve the anti-corrosion, weather resistance, and media resistance of polyurea coatings.

[0066] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A weather-resistant and corrosion-resistant polyurea coating, characterized in that, Includes component A and component B; Component A comprises the following components by mass percentage: Polyaspartic acid ester resin: 60%–75%; Light stabilizer - fluorocarbon chain modified nano-silica: 10%–15%; Diluent: 15%–25%; Component B includes hexamethylene diisocyanate isocyanurate trimer.

2. The weather-resistant and corrosion-resistant polyurea coating according to claim 1, characterized in that: The light stabilizer-fluorocarbon chain modified nano-silica is prepared by a method including the following steps: a) Mix aliphatic isocyanate and fluorinated monohydric alcohol, and then carry out an addition reaction under a protective atmosphere to obtain fluorinated isocyanate; b) Disperse nano-silica in a solvent, then add a hindered amine light stabilizer containing polyfunctional amino groups and a silane coupling agent containing isocyanate groups to modify the surface of nano-silica, then add fluorinated isocyanate to carry out an addition reaction, and then separate, purify and dry the product to obtain light stabilizer-fluorocarbon chain modified nano-silica.

3. The weather-resistant and corrosion-resistant polyurea coating according to claim 2, characterized in that: The molar ratio of the aliphatic isocyanate and the fluorinated monohydric alcohol in step a) is 1:0.9 to 1.0; the aliphatic isocyanate in step a) is at least one of 4,4-diisocyanate dicyclohexylmethane, isophorone diisocyanate, and hexamethylene diisocyanate; the fluorinated monohydric alcohol in step a) is at least one of 4,4,5,5,6,6,7,7,7-nonafluoro-1-heptanol, 1H,1H,2H,2H-perfluoro-1-decanol, 1H,1H,2H,2H-perfluorooctanol, 3-perfluorohexylpropanol, 3-perfluorooctylpropanol, and 1H,1H,2H,2H-perfluorohexyl-1-ol.

4. The weather-resistant and corrosion-resistant polyurea coating according to claim 2 or 3, characterized in that: The addition reaction in step a) is carried out at a temperature of 75℃ to 100℃ for a reaction time of 3h to 6h.

5. The weather-resistant and corrosion-resistant polyurea coating according to claim 2, characterized in that: The particle size of the nano-silica in step b) is 10 nm to 60 nm; the hindered amine light stabilizer containing polyfunctional amino groups in step b) is hindered amine light stabilizer HS-944; the silane coupling agent containing isocyanate groups in step b) is at least one of 3-isocyanopropyltrimethoxysilane and propyltriethoxysilane.

6. The weather-resistant and corrosion-resistant polyurea coating according to claim 2 or 5, characterized in that: The surface modification in step b) is carried out at a temperature of 80℃ to 110℃ for a reaction time of 3h to 6h.

7. The weather-resistant and corrosion-resistant polyurea coating according to claim 2 or 5, characterized in that: The addition reaction in step b) is carried out at a temperature of 40℃ to 60℃ for a reaction time of 1h to 3h.

8. The weather-resistant and corrosion-resistant polyurea coating according to claim 1 or 2, characterized in that: The diluent is at least one of tetrahydrofuran and butyl acetate.

9. A method for preparing a weather-resistant and corrosion-resistant polyurea coating as described in any one of claims 1 to 8, characterized in that, Includes the following steps: 1) Preparation of components A and B: Preparation of component A: Weigh out polyaspartic acid ester resin, light stabilizer-fluorocarbon chain modified nano silica and diluent, mix them evenly to obtain component A; Preparation of component B: Weigh out hexamethylene diisocyanate isocyanurate trimer according to an NCO index of 1.05 to 1.15 to obtain component B; 2) Mix component A and component B evenly to obtain a weather-resistant and corrosion-resistant polyurea coating.

10. The application of a weather-resistant and corrosion-resistant polyurea coating as described in any one of claims 1 to 8 for corrosion protection of steel structures.

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