High performance hydroxyl silicone oil modified waterborne polyurethane coating and preparation method thereof

Abstract

The application belongs to the technical field of water-based polymer materials, and particularly relates to a high-performance hydroxyl silicone oil modified water-based polyurethane coating and a preparation method thereof. The coating comprises the following components in parts by weight: 100 parts of water-based polyurethane emulsion, 20-30 parts of modified hydroxyl silicone oil hybrid component, 0.6-1.2 parts of dispersant, 8-18 parts of pigment and filler, 0.2-0.5 parts of defoaming agent, 0.3-0.8 parts of thickening agent, and 5-15 parts of deionized water. The coating is prepared through pre-mixing, pigment and filler dispersion, blending, degassing and filtration. The prepared water-based polyurethane coating has significant improvements in adhesion, hardness, water resistance, flame resistance, impact resistance and self-repairing rate.

Description

Technical Field

[0001] This invention belongs to the field of waterborne polymer materials technology, specifically relating to a high-performance hydroxyl silicone oil modified waterborne polyurethane coating and its preparation method. Background Technology

[0002] Waterborne polyurethane (WPU) coatings are gradually replacing traditional solvent-based polyurethane coatings due to their environmental friendliness, low VOC emissions, and non-toxicity and non-flammability, and are receiving increasing attention in the coatings industry. Waterborne polyurethane has a unique molecular structure and aggregation state, and its films exhibit excellent mechanical properties, abrasion resistance, and adhesion, leading to its widespread application in clothing, footwear, furniture, automotive, textile auxiliaries, coatings, and adhesives.

[0003] However, existing waterborne polyurethane coatings still face some technical bottlenecks in practical applications. First, the presence of hydrophilic groups in the molecular chain of waterborne polyurethane results in significantly lower water resistance compared to solvent-based polyurethane coatings. In humid environments or under prolonged immersion conditions, whitening, blistering, and even peeling are common. Second, traditional waterborne polyurethane coatings suffer from insufficient heat resistance and flame retardancy, making them prone to thermal degradation at high temperatures. Furthermore, their flame retardancy typically relies on additives of inorganic flame retardants (such as aluminum hydroxide and magnesium hydroxide). While these additives can improve flame retardancy, they can impair the transparency and mechanical properties of the coating, increasing its brittleness and reducing its impact resistance. In addition, waterborne polyurethane coatings inevitably experience microcracks due to external impacts during use. Crack propagation leads to the failure of the coating's protective function, shortening its service life.

[0004] To address the aforementioned shortcomings of waterborne polyurethane, researchers have attempted to modify it by introducing organosilicon components. Hydroxyl silicone oil (hydroxyl-terminated polydimethylsiloxane, HO-PDMS) has become an ideal modifier due to its low surface tension, excellent hydrophobicity, and heat resistance. Studies have shown that the introduction of hydroxyl silicone oil can reduce the surface energy of waterborne polyurethane films, eliminate surface stickiness, and significantly improve the film's flexibility and water resistance. Simultaneously, due to the high bond energy of the silicon-oxygen bond (Si-O), the hydrogen bonding between molecular chains is enhanced, significantly increasing the tensile strength of the film. However, ordinary silicone oil has poor compatibility with waterborne polyurethane and is prone to migration; physical blending alone is insufficient to achieve a durable and stable modification effect. Therefore, it is necessary to introduce the silicone oil component into the polyurethane molecular chain through chemical bonding.

[0005] On the other hand, self-healing is a cutting-edge technology for extending the service life of coatings. In recent years, intrinsic self-healing polyurethanes based on Diels-Alder reversible covalent bonds have become a research hotspot. Diels-Alder bonds are thermally reversible under certain temperature conditions. When the coating is damaged, heating can induce a reverse reaction of the DA bonds, causing the broken bonds to recombine and thus repairing microcracks. However, existing self-healing polyurethanes containing DA bonds mainly rely on a single self-healing mechanism and face the dilemma of balancing repair efficiency and mechanical strength. If they can be synergistically designed with crosslinking toughening systems, it is expected to simultaneously improve the impact resistance and self-healing ability of the coating.

[0006] Therefore, developing a high-performance waterborne polyurethane coating that combines excellent water resistance, flame retardancy, impact resistance, and self-healing properties has significant industrial application value and practical significance. Summary of the Invention

[0007] To address the technical challenges of insufficient water resistance, poor flame retardancy, unsatisfactory impact resistance, and lack of self-healing ability in existing waterborne polyurethane coatings, this invention provides a high-performance hydroxyl silicone oil-modified waterborne polyurethane coating and its preparation method.

[0008] The present invention adopts the following technical solution: A high-performance hydroxyl silicone oil modified waterborne polyurethane coating comprises the following components in parts by weight: 100 parts of waterborne polyurethane emulsion, 20-30 parts of modified hydroxyl silicone oil hybrid component, 0.6-1.2 parts of dispersant, 8-18 parts of pigments and fillers, 0.2-0.5 parts of defoamer, 0.3-0.8 parts of thickener, and 5-15 parts of deionized water; The modified hydroxyl silicone oil hybrid component is prepared by pre-reaction of hydroxyl silicone oil, self-healing polymer and crosslinking agent phosphonic isocyanate, with the mass ratio of the three being hydroxyl silicone oil: self-healing polymer: phosphonic isocyanate = 10:(4~6):(1.5~2.5); the self-healing polymer is prepared by Diels-Alder reaction of cis-1,3-butadiene and maleic anhydride.

[0009] In some embodiments, the aqueous polyurethane emulsion is a sulfonic acid-based aqueous polyurethane emulsion.

[0010] In some embodiments, the hydroxyl silicone oil is α,ω-dihydroxypolydimethylsiloxane.

[0011] In some embodiments, the dispersant is sodium polyacrylate or potassium polyacrylate; the pigments and fillers are at least one of titanium dioxide, talc, quartz powder or calcium carbonate, preferably titanium dioxide and talc in a mass ratio of 2:1.

[0012] In some embodiments, the defoamer is a silicone defoamer or a polyether-modified defoamer; the thickener is an associative polyurethane thickener.

[0013] In some embodiments, the self-healing polymer is prepared by the following method: (1) Under inert gas protection, an organic solvent is added to a reaction vessel, and then cis-1,3-butadiene and maleic anhydride are added to the reaction vessel at a molar ratio of 1.05:1, mixed evenly, and then triethylamine, an amino catalyst, is added. The amount of the amino catalyst is 0.2~0.5% of the total mass of cis-1,3-butadiene and maleic anhydride; (2) The reaction vessel is heated to 65~80°C, and the reaction is continuously stirred for 2~3 hours. After the reaction is completed, the solvent is removed to obtain the self-healing polymer. In some embodiments, the modified hydroxyl silicone oil hybrid component is prepared by the following method: (1) Under inert gas protection, hydroxyl silicone oil, phosphonic diethoxyisocyanate and dibutyltin dilaurate catalyst are added to the reaction vessel. The amount of catalyst is 0.03~0.08% of the mass of hydroxyl silicone oil. The temperature is raised to 75~85℃ and reacted for 1~2 hours to obtain a phosphorus-containing silicone oil prepolymer. (2) After the phosphorus-containing silicone oil prepolymer obtained in step (1) is cooled to 55~65℃, a self-healing polymer is added and the reaction is continued to be stirred for 1~2 hours to obtain a homogeneous hybrid resin, which is the modified hydroxyl silicone oil hybrid component.

[0014] Another objective of this invention is to provide a method for preparing the above-mentioned high-performance hydroxyl silicone oil modified waterborne polyurethane coating, comprising the following steps: (1) Premixing: The waterborne polyurethane emulsion and the modified hydroxyl silicone oil hybrid components are added to a dispersion tank according to the metering, and stirred at 400~600 rpm for 15~20 minutes to mix evenly; (2) Pigment and filler dispersion: Dispersant, pigments and fillers and 1 / 2 of the formulation amount of deionized water are added to the mixture obtained in step (1), and dispersed at 1000~1200 rpm for 30~40 minutes until the fineness is ≤25μm; (3) Blending: The mixture is cooled to room temperature, and defoamer, thickener and the remaining 1 / 2 of the formulation amount of deionized water are added to adjust the viscosity to 40~60 seconds for a Forecast-4 cup; (4) Degassing and filtration: Vacuum degassing, and filtration through a 200-mesh filter to obtain the finished product.

[0015] In some embodiments, the vacuum degassing conditions in step (4) are a vacuum degree below -0.095 MPa and a degassing time of 10 to 15 minutes.

[0016] In some embodiments, the curing conditions of the coating are: surface drying at room temperature for 2 hours after application, followed by baking at 80°C for 3-4 hours.

[0017] Compared with existing technologies, the high-performance hydroxyl silicone oil modified waterborne polyurethane coating provided by this invention has the following advantages: (1) In this invention, hydroxyl silicone oil (HO-PDMS) is covalently integrated into the polyurethane molecular network, overcoming the defects of easy migration and poor compatibility of physically blended silicone oil. The low surface tension of hydroxyl silicone oil endows the coating with excellent hydrophobicity, and the high bond energy of silicon-oxygen bonds (Si-O) and the synergistic effect of hydrogen bonds between molecular chains significantly improve the tensile strength and flexibility of the film; (2) The self-healing polymer prepared by the present invention from cis-1,3-butadiene and maleic anhydride via a DA reaction has high thermal reversibility. When the coating is subjected to impact and microcracks are generated, heating to above 80°C can trigger a reverse DA reaction, which recombines the broken chemical bonds, repairs the cracks, prevents their propagation, and can significantly extend the service life of the coating; (3) The present invention uses phosphonic diethoxyisocyanate, whose phosphate ester group reacts with the active groups of hydroxy silicone oil and DA polymer to form a stable cross-linked network structure, which improves the thermal stability, mechanical strength and wear resistance of the coating film; secondly, DOPI decomposes at high temperature to produce non-flammable phosphoric acid substances, forming a dense protective carbon layer to inhibit flame propagation; at the same time, phosphorus can capture gaseous free radicals, inhibit the generation of pyrolysis gases, and reduce the flammability of the material. Detailed Implementation

[0018] The present invention will be further described below through specific embodiments, but this is not a limitation of the present invention. Those skilled in the art can make various modifications or improvements based on the basic idea of ​​the present invention, but as long as they do not depart from the basic idea of ​​the present invention, they are all within the protection scope of the present invention.

[0019] Unless otherwise specified, the methods used in the following examples and comparative examples are all prior art; reagents not specifically mentioned are conventional reagents, all of which can be purchased from conventional reagent manufacturers and distributors. Some raw material information is as follows: Waterborne polyurethane emulsion: sulfonic acid type WPU, solid content 35±2%, acid value <20 mg KOH / g; Hydroxysilicone oil (HO-PDMS): hydroxyl value 35~45 mg KOH / g, number average molecular weight approximately 2000; Diethoxyphosphonic isocyanate (DOPI): CAS No. 20039-33-2; cis-1,3-Butadiene: CAS No. 106-99-0; Maleic anhydride: CAS No. 108-31-6; Triethylamine: CAS No. 121-44-8; Dibutyltin dilaurate (DBTDL): CAS No. 77-58-7.

[0020] Example 1

[0021] Preparation method of self-healing polymer: Under nitrogen protection, 300 mL of dichloromethane was added to the reactor. Then, cis-1,3-butadiene and maleic anhydride were added to the reactor at a molar ratio of 1.05:1 (maleic anhydride feed amount was fixed at 98 g, 1.0 mol; cis-1,3-butadiene feed amount was 56.8 g, 1.05 mol). After mixing thoroughly, 0.5 g of triethylamine, an amino catalyst, was added. The reactor was heated to 70 °C and the reaction was continuously stirred for 2.5 hours. After the reaction was completed, dichloromethane was removed by vacuum distillation to obtain a pale yellow viscous self-healing polymer (DA polymer). The product was sealed and stored for later use.

[0022] Preparation method of modified hydroxyl silicone oil hybrid components: Under nitrogen protection, 100g of hydroxyl silicone oil, 20g of phosphonodiesterephthalate (DOPI), and 0.06g of dibutyltin dilaurate (DBTDL) catalyst were added to a reaction vessel. The mixture was heated to 80°C and reacted for 1.5 hours to obtain a phosphorus-containing silicone oil prepolymer. After cooling to 60°C, 50g of a self-healing polymer (DA polymer) was added, and the reaction was continued with stirring for 1.5 hours to obtain 170g of a homogeneous hybrid resin, which is the modified hydroxyl silicone oil hybrid component.

[0023] A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating, comprising the following steps: (1) Premixing: Add 100g of waterborne polyurethane emulsion and 25g of modified hydroxyl silicone oil hybrid component to a dispersion tank and stir at 500rpm for 18 minutes.

[0024] (2) Pigment and filler dispersion: Add 0.8g of dispersant, 12g of pigment and filler and 5g of deionized water, disperse at 1100rpm for 35 minutes, and use a scraper fineness meter to test the fineness ≤25μm.

[0025] (3) Mixing: Let it cool naturally to room temperature, add 0.3g of defoamer, 0.5g of thickener and 5g of remaining deionized water, stir at 600rpm for 15 minutes, and measure the viscosity with a Forte 4 cup to be 50 seconds.

[0026] (4) Degassing and filtration: Degas for 12 minutes under a vacuum of -0.095MPa, and then filter through a 200-mesh filter to obtain the finished coating.

[0027] Example 2

[0028] Preparation method of self-healing polymer: Same as Example 1, but the reaction conditions were adjusted to: reaction temperature 65°C, reaction time 3 hours.

[0029] Preparation method of modified hydroxyl silicone oil hybrid components: Under nitrogen protection, 100g of hydroxyl silicone oil, 15g of phosphonodiesterate diethoxyisocyanate (DOPI) and 0.03g of catalyst dibutyltin dilaurate (DBTDL) were added to the reaction vessel and reacted at 75°C for 2 hours. The temperature was then lowered to 55°C, 40g of DA polymer was added, and the reaction was continued for 2 hours to obtain 155g of modified hydroxyl silicone oil hybrid component.

[0030] A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating, comprising the following steps: (1) Premixing: Add 100g of waterborne polyurethane emulsion and 20g of modified hydroxyl silicone oil hybrid component to a dispersion tank and stir at 400rpm for 20 minutes.

[0031] (2) Pigment and filler dispersion: Add 0.6g of dispersant, 8g of pigment and filler and 2.5g of deionized water, disperse at 1000rpm for 40 minutes, and test the fineness ≤25μm.

[0032] (3) Mixing: Let it cool naturally to room temperature, add 0.2g of defoamer, 0.3g of thickener and 2.5g of remaining deionized water, stir at 500rpm for 20 minutes, and adjust the viscosity to 40 seconds for Fort-4 cup.

[0033] (4) Degassing and filtration: Degas for 10 minutes under a vacuum of -0.095MPa, and then filter through a 200-mesh filter to obtain the finished coating.

[0034] Example 3

[0035] Preparation method of self-healing polymer: Same as Example 1, but the reaction conditions are adjusted to: reaction temperature 80°C, reaction time 2 hours.

[0036] Preparation method of modified hydroxyl silicone oil hybrid components: Under nitrogen protection, 100g of hydroxyl silicone oil, 25g of phosphonodiesterate diethoxyisocyanate (DOPI) and 0.08g of dibutyltin dilaurate catalyst (DBTDL) were added to the reaction vessel and reacted at 85°C for 2 hours; the temperature was then lowered to 65°C, 60g of DA polymer was added, and the reaction was continued for 1 hour to obtain 185g of modified hydroxyl silicone oil hybrid component.

[0037] A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating, comprising the following steps: (1) Premixing: Add 100g of waterborne polyurethane emulsion and 30g of modified hydroxyl silicone oil hybrid component to a dispersion tank and stir at 600rpm for 15 minutes.

[0038] (2) Pigment and filler dispersion: Add 1.2g of dispersant, 18g of pigment and filler and 7.5g of deionized water, disperse at 1200rpm for 30 minutes, and the fineness is ≤25μm.

[0039] (3) Mixing: Let it cool naturally to room temperature, add 0.5g of defoamer, 0.8g of thickener and 7.5g of remaining deionized water, stir at 700rpm for 10 minutes, and adjust the viscosity to 60 seconds for Fort-4 cup.

[0040] (4) Degassing and filtration: Degas for 15 minutes under a vacuum of -0.095MPa, and then filter through a 200-mesh filter to obtain the finished coating.

[0041] Example 4

[0042] Preparation method of self-healing polymer: Same as Example 1.

[0043] Preparation method of modified hydroxyl silicone oil hybrid components: Under nitrogen protection, 100g of hydroxyl silicone oil, 18g of phosphonium diethoxyisocyanate (DOPI) and 0.05g of dibutyltin dilaurate (DBTDL) catalyst were added to the reaction vessel, and the reaction was carried out at 78°C for 1.8 hours. The temperature was then lowered to 62°C, 45g of DA polymer was added, and the reaction was continued for another 1.8 hours to obtain 163g of modified hydroxyl silicone oil hybrid component.

[0044] A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating, comprising the following steps: (1) Premixing: Add 100g of waterborne polyurethane emulsion and 25g of modified hydroxyl silicone oil hybrid component to a dispersion tank and stir at 550rpm for 16 minutes.

[0045] (2) Pigment and filler dispersion: Add 0.8g of dispersant, 12g of pigment and filler and 5g of deionized water, disperse at 1150rpm for 32 minutes, and use a scraper fineness meter to test the fineness ≤25μm.

[0046] (3) Mixing: Let it cool naturally to room temperature, add 0.3g of defoamer, 0.5g of thickener and 5g of remaining deionized water, stir at 600rpm for 15 minutes, and measure the viscosity with a Forte 4 cup. The viscosity is 55 seconds.

[0047] (4) Degassing and filtration: Degas for 13 minutes under a vacuum of -0.095MPa, and then filter through a 200-mesh filter to obtain the finished coating.

[0048] Comparative Example 1 The difference from Example 1 is that the modified hydroxyl silicone oil hybrid component is not added to the coating formulation, but is made up with an equal amount of waterborne polyurethane emulsion.

[0049] A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating, comprising the following steps: (1) Pigment and filler dispersion: Add 125g of waterborne polyurethane emulsion to a dispersion tank, add 0.8g of dispersant, 12g of pigment and filler and 5g of deionized water respectively, disperse at 1100rpm for 35 minutes, and use a scraper fineness meter to detect fineness ≤25μm.

[0050] (2) Mixing: Let it cool naturally to room temperature, add 0.3g of defoamer, 0.5g of thickener and 5g of remaining deionized water, stir at 600rpm for 15 minutes, and measure the viscosity with a Forte 4 cup. The viscosity is 50 seconds.

[0051] (3) Degassing and filtration: Degas for 12 minutes under a vacuum of -0.095MPa, and then filter through a 200-mesh filter to obtain the finished coating.

[0052] Comparative Example 2 Preparation method of modified hydroxyl silicone oil hybrid components: Under nitrogen protection, 100g of hydroxyl silicone oil, 20g of phosphonodiesterate diethoxyisocyanate (DOPI) and 0.06g of dibutyltin dilaurate (DBTDL) catalyst were added to the reaction vessel, and the temperature was raised to 80℃ and reacted for 1.5 hours to obtain 120g of phosphorus-containing silicone oil prepolymer, which is the modified hydroxyl silicone oil hybrid component.

[0053] A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating, comprising the following steps: (1) Premixing: Add 100g of waterborne polyurethane emulsion and 25g of modified hydroxyl silicone oil hybrid component to a dispersion tank and stir at 500rpm for 18 minutes.

[0054] (2) Pigment and filler dispersion: Add 0.8g of dispersant, 12g of pigment and filler and 5g of deionized water, disperse at 1100rpm for 35 minutes, and use a scraper fineness meter to test the fineness ≤25μm.

[0055] (3) Mixing: Let it cool naturally to room temperature, add 0.3g of defoamer, 0.5g of thickener and 5g of remaining deionized water, stir at 600rpm for 15 minutes, and measure the viscosity with a Forte 4 cup to be 50 seconds.

[0056] (4) Degassing and filtration: Degas for 12 minutes under a vacuum of -0.095MPa, and then filter through a 200-mesh filter to obtain the finished coating.

[0057] Comparative Example 3 Preparation method of modified hydroxyl silicone oil hybrid components: Under nitrogen protection, 100g of hydroxyl silicone oil and 50g of self-healing polymer (DA polymer) were added to the reaction vessel and stirred at 60°C and 300rpm for 1.5 hours to obtain 150g of physical blend, which is the modified hydroxyl silicone oil hybrid component.

[0058] A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating is the same as in Example 1.

[0059] Comparative Example 4 A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating, comprising the following steps: (1) Mix 100g of waterborne polyurethane emulsion with 14.7g of unmodified hydroxyl silicone oil and stir at 500rpm for 18 minutes; (2) Add 0.8g of dispersant, 12g of pigments and fillers and 5g of deionized water and disperse at 1100rpm for 35 minutes; (3) Add 0.3g of defoamer, 0.5g of thickener and the remaining 5g of deionized water and stir at 600rpm for 15 minutes; (4) Degas and filter as in Example 1.

[0060] Experimental Example: Performance Testing 1. Test materials: Waterborne polyurethane coatings prepared in Examples 1-4 and Comparative Examples 1-4 of this invention.

[0061] 2. Test methods: (1) Adhesion was tested according to GB / T 9286-1998, pencil hardness was tested according to GB / T 6739-2006, water resistance was tested according to GB / T 1733-1993, flame retardancy was tested according to UL 94 vertical burning test, impact resistance was tested according to GB / T 1732-1993, and flexibility was tested according to GB / T 1731-1993; (2) Self-repair rate test: Sample preparation: Make the coating into a 1mm thick film and cut it into dumbbell-shaped strips of 10cm×5mm.

[0062] Damage: Cut the strip completely in the middle with a sharp blade (cut width approximately 0.5 mm).

[0063] Repair conditions: Place the cut sample in an 80℃ oven for 4 hours for repair, and then allow it to cool naturally to room temperature.

[0064] Tensile test: Using a universal tensile testing machine (tensile rate 50 mm / min), the maximum fracture strain (ε0 and ε1) of the original (uncut) and repaired specimens were tested respectively; no less than 5 parallel specimens were tested for each group of specimens.

[0065] Calculation formula: Self-repair rate (%) = (ε1 / ε0) × 100%.

[0066] 3. The test results are shown in Table 1: Table 1 Performance Test Results

[0067] As shown in Table 1, the waterborne polyurethane coatings prepared in Examples 1-4 of this invention are significantly superior to the comparative examples in terms of adhesion, hardness, water resistance, flame retardancy, impact resistance, and self-healing rate. This demonstrates the synergistic effect between hydroxyl silicone oil, DA self-healing polymer, and DOPI crosslinking agent: hydroxyl silicone oil is introduced into the polyurethane network through chemical bonding, giving the coating excellent hydrophobicity (water resistance) and flexibility; DA self-healing polymer gives the coating thermally reversible self-healing ability and impact energy dissipation ability (impact resistance); DOPI crosslinking agent has both crosslinking network construction and phosphorus-based flame retardant functions, improving the overall mechanical properties and flame retardant safety of the coating. All three are indispensable, and the absence of any one component will lead to a significant deterioration in the overall performance.

[0068] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A high-performance hydroxyl silicone oil modified waterborne polyurethane coating, characterized in that, The product comprises the following components by weight: 100 parts of waterborne polyurethane emulsion, 20-30 parts of modified hydroxyl silicone oil hybrid component, 0.6-1.2 parts of dispersant, 8-18 parts of pigments and fillers, 0.2-0.5 parts of defoamer, 0.3-0.8 parts of thickener, and 5-15 parts of deionized water; The modified hydroxyl silicone oil hybrid component is prepared by pre-reaction of hydroxyl silicone oil, self-healing polymer and crosslinking agent phosphonic isocyanate, with the mass ratio of the three being hydroxyl silicone oil: self-healing polymer: phosphonic isocyanate = 10:(4~6):(1.5~2.5); the self-healing polymer is prepared by Diels-Alder reaction of cis-1,3-butadiene and maleic anhydride.

2. The high-performance hydroxyl silicone oil modified waterborne polyurethane coating according to claim 1, characterized in that, The aqueous polyurethane emulsion is a sulfonic acid type aqueous polyurethane emulsion.

3. The high-performance hydroxyl silicone oil modified waterborne polyurethane coating according to claim 1, characterized in that, The hydroxyl silicone oil is α,ω-dihydroxypolydimethylsiloxane.

4. The high-performance hydroxyl silicone oil modified waterborne polyurethane coating according to claim 1, characterized in that, The dispersant is sodium polyacrylate or potassium polyacrylate; the pigments and fillers are at least one of titanium dioxide, talc, quartz powder or calcium carbonate, preferably titanium dioxide and talc in a mass ratio of 2:

1.

5. The high-performance hydroxyl silicone oil modified waterborne polyurethane coating according to claim 1, characterized in that, The defoamer is an organosilicon defoamer or a polyether-modified defoamer; the thickener is an associative polyurethane thickener.

6. The high-performance hydroxyl silicone oil modified waterborne polyurethane coating according to claim 1, characterized in that, The self-healing polymer is prepared by the following method: (1) Under the protection of an inert gas, an organic solvent is added to the reactor, and then cis-1,3-butadiene and maleic anhydride are added to the reactor at a molar ratio of 1.05:1 and mixed evenly. Then, the amino catalyst triethylamine is added, and the amount of the amino catalyst is 0.2~0.5% of the total mass of cis-1,3-butadiene and maleic anhydride; (2) The reactor is heated to 65~80℃ and stirred continuously for 2~3 hours. After the reaction is completed, the solvent is removed to obtain the self-healing polymer.

7. The high-performance hydroxyl silicone oil modified waterborne polyurethane coating according to claim 1, characterized in that, The modified hydroxyl silicone oil hybrid component is prepared by the following method: (1) Under inert gas protection, hydroxyl silicone oil, phosphonic diethoxyisocyanate and dibutyltin dilaurate catalyst are added to the reaction vessel. The amount of catalyst is 0.03~0.08% of the mass of hydroxyl silicone oil. The temperature is raised to 75~85℃ and reacted for 1~2 hours to obtain a phosphorus-containing silicone oil prepolymer. (2) After the phosphorus-containing silicone oil prepolymer obtained in step (1) is cooled to 55~65℃, a self-healing polymer is added and the reaction is continued to be stirred for 1~2 hours to obtain a homogeneous hybrid resin, which is the modified hydroxyl silicone oil hybrid component.

8. A method for preparing a high-performance hydroxyl silicone oil modified waterborne polyurethane coating as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Premixing: Add the waterborne polyurethane emulsion and the modified hydroxyl silicone oil hybrid component to the dispersion tank according to the metering, and stir at 400~600 rpm for 15~20 minutes to mix evenly; (2) Pigment and filler dispersion: Add the dispersant, pigments and fillers and 1 / 2 of the formula amount of deionized water to the mixture obtained in step (1), and disperse at 1000~1200 rpm for 30~40 minutes until the fineness is ≤25μm; (3) Blending: Cool to room temperature, add defoamer, thickener and the remaining 1 / 2 of the formula amount of deionized water, and adjust the viscosity to 40~60 seconds for a Fore-4 cup; (4) Degassing and filtration: Degas under vacuum, and filter through a 200 mesh filter to obtain the finished product.

9. The preparation method according to claim 8, characterized in that, The vacuum degassing conditions described in step (4) are a vacuum degree below -0.095 MPa and a degassing time of 10 to 15 minutes.

10. The high-performance hydroxyl silicone oil modified waterborne polyurethane coating according to any one of claims 1-7, characterized in that, The curing conditions for the coating are: after application, surface dry at room temperature for 2 hours, then bake at 80°C for 3-4 hours.

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