Water-based two-component polyurethane coating and preparation method thereof
By combining modified hydroxy polyacrylate with phosphorus-containing polyisocyanate, the adhesion and water resistance of polyurethane coatings are enhanced by using silicone groups, and the flame retardant performance is improved by phosphorus-containing polyisocyanate, which solves the adhesion of water-based polyurethane coatings and The problem of insufficient flame retardant performance has achieved better mechanical properties and application range.
Patent Information
- Application Number
- CN202411397713.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-09
- Publication Date
- 2024-12-06
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
During use, water-based polyurethane coatings are susceptible to rainwater erosion, their adhesion is reduced, and their ultimate oxygen index is low and flammable. They need to improve their adhesion and flame retardant properties to expand their application range.
Modified hydroxy polyacrylate dispersion is used to combine with phosphorus-containing polyisocyanate, and combine with the substrate surface through silicone groups to enhance cross-linking, improve adhesion and water resistance, and pass the flame retardant element of phosphorus-containing polyisocyanate. Improve flame retardant performance.
It significantly improves the adhesion, water resistance and flame retardant properties of polyurethane coatings, enhances its mechanical properties, and expands its application range.
Smart Images
Figure CN119081526A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of coatings, in particular to a water-based two-component polyurethane coating and a preparation method thereof. Background Art
[0002] Waterborne polyurethane coatings are widely used in surface coatings of wood, plastics, etc. due to their good environmental performance, decorative properties, wear resistance, and anti-corrosion properties. However, polyurethane coatings are mainly combined with the substrate by hydrogen bonds and van der Waals forces. However, as they are used, they will be eroded by rainwater, so the adhesion of the coating will decrease significantly. In addition, the limiting oxygen index of polyurethane coatings is low, which makes them flammable. Therefore, it is necessary to modify the adhesion and flame retardant properties of polyurethane coatings to expand their application range.
[0003] For example, the patent with application publication number CN 104046224 A discloses a method for preparing a flame-retardant waterborne polyurethane coating. The invention uses 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphophananthrene-10-oxide, hexamethylene diisocyanate, etc. as raw materials to prepare a polyurethane prepolymer, and further prepare a polyurethane coating. The prepared polyurethane coating has good flame retardant effect and mechanical properties, but does not improve the adhesion of the polyurethane coating. Summary of the invention
[0004] The object of the present invention is to provide a water-based two-component polyurethane coating and a preparation method thereof, which has the advantages of good flame retardant effect and strong adhesion.
[0005] To achieve the above object, the present invention provides the following technical solution: a water-based two-component polyurethane coating, the water-based two-component polyurethane coating is composed of the following components in percentage by mass: 40-55% of a modified hydroxy polyacrylate dispersion, 10-20% of a phosphorus-containing polyisocyanate, 0.4-0.6% of a defoamer, 0.6-1% of a leveling agent, 1.5-3% of a film-forming aid, and the balance is deionized water, and the sum of the percentages of the above components is 100%;
[0006] The preparation method of the water-based two-component polyurethane coating is as follows:
[0007] Add the modified hydroxy polyacrylate dispersion into the paint mixing tank, add defoamer, leveling agent, film-forming aid, deionized water, stir and disperse for 20-50 minutes, then add phosphorus-containing polyisocyanate, continue stirring for 20-40 minutes, filter, and obtain a water-based two-component polyurethane coating.
[0008] Furthermore, the preparation method of the modified hydroxy polyacrylate dispersion is:
[0009] (1) Under nitrogen conditions, diallylamine and 3-isocyanatepropyltriethoxysilane are added to a flask containing tetrahydrofuran solvent, stirred and dispersed, heated to 45-60°C, and reacted for 2-5 hours. After the reaction is completed, the solvent is evaporated under reduced pressure, washed with deionized water, and dried to obtain bis-vinyl silane;
[0010] (2) Add an emulsifier and sodium bicarbonate to a flask filled with deionized water, stir and mix evenly, add methyl methacrylate, hydroxyethyl methacrylate and bis(vinylsilane) thereto, stir and mix evenly, add potassium persulfate thereto, heat to 80°C, react for 20-40 minutes, add dimethylethanolamine as a neutralizer, control the pH to 7-8, heat to 85°C, mature for 2-3 hours, cool and discharge, filter, and obtain a modified hydroxy polyacrylate dispersion.
[0011] Furthermore, in (1), the usage ratio of diallylamine and 3-isocyanatepropyltriethoxysilane is 100g:(250-300)g.
[0012] Furthermore, in (2), the usage ratio of methyl methacrylate, hydroxyethyl methacrylate and bis(vinyl)silane is 100 g:(50-150) g:(30-60) g.
[0013] Furthermore, in (2), the emulsifier is sodium dodecyl benzene diphenyl oxide disulfonate, and the amount of the emulsifier is 3-6% of the total mass of methyl methacrylate, hydroxyethyl methacrylate, and bis-alkenyl silane; the amount of potassium persulfate is 2-5% of the total mass of methyl methacrylate, hydroxyethyl methacrylate, and bis-alkenyl silane; the amount of sodium bicarbonate is 1-3% of the total mass of methyl methacrylate, hydroxyethyl methacrylate, and bis-alkenyl silane.
[0014] Furthermore, the preparation method of the phosphorus-containing polyisocyanate is:
[0015] S1. Add pentaerythritol diphosphate diphosphoryl chloride to a 30% acetone aqueous solution, stir and mix evenly, add tris(hydroxymethyl)aminomethane and triethylamine at 0-10° C., stir and react for 2-5 hours, continue to heat to 50-60° C., react for 6-12 hours, and after the reaction is completed, cool to room temperature, rotary evaporate, wash with chloroform, and dry to obtain a phosphorus-containing hexahydric alcohol;
[0016] S2. Under nitrogen conditions, add the phosphorus-containing hexavalent alcohol and isophorone diisocyanate into a flask filled with tetrahydrofuran solvent, stir and disperse, then add dibutyltin dilaurate thereto, react at 40-50°C for 3-6h, after the reaction is completed, rotary evaporate, wash with deionized water, and dry to obtain the phosphorus-containing polyisocyanate.
[0017] Furthermore, in S1, the usage ratio of pentaerythritol diphosphate diphosphoryl chloride, tris(hydroxymethyl)aminomethane and triethylamine is 100 g:(80-120) g:(200-240) g.
[0018] Furthermore, in S2, the usage ratio of phosphorus-containing hexahydric alcohol and isophorone diisocyanate is 100g:(280-340)g.
[0019] Furthermore, in S2, the amount of dibutyltin dilaurate used is 0.02-0.1% of the total mass of the phosphorus-containing hexahydric alcohol and isophorone diisocyanate.
[0020] Reaction mechanism: The present invention uses diallylamine and 3-isocyanatopropyltriethoxysilane as raw materials to synthesize bis-alkenyl silane, which is then copolymerized with methyl methacrylate and the like under the initiation of potassium persulfate to form a modified hydroxy polyacrylate dispersion. The present invention uses pentaerythritol diphosphate diphosphoryl chloride, trishydroxymethylaminomethane, isophorone diisocyanate and the like as raw materials to synthesize phosphorus-containing polyisocyanate. Finally, a defoamer, deionized water and the like are added to the modified hydroxy polyacrylate dispersion, stirred and mixed evenly, and then the phosphorus-containing polyisocyanate is added thereto, stirred and dispersed to obtain a water-based two-component polyurethane coating.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] The modified hydroxy polyacrylate dispersion prepared by a series of reactions contains a large number of siloxane groups, and the -Si-OH groups generated after hydrolysis can be combined with the surface of the substrate, significantly improving the adhesion of the coating on the surface of the substrate. In addition, the siloxane groups can be hydrolyzed and condensed into Si-O-Si structures, generating a strengthened cross-linking effect and increasing the water resistance of the coating.
[0023] The phosphorus-containing polyisocyanate prepared by the present invention has a novel structure and a simple preparation method. It contains flame retardant elements and is combined with a silicon-containing modified hydroxy polyacrylate dispersion to prepare a polyurethane coating having good flame retardant properties. In addition, since the phosphorus-containing polyisocyanate contains a hexaisocyanate structure, when combined with the modified hydroxy polyacrylate dispersion, more chemical and physical crosslinking sites can be generated, further enhancing the mechanical properties of the polyurethane coating. The polyurethane coating prepared by the present invention has good flame retardant properties, adhesion and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is the reaction route of phosphorus-containing polyisocyanates;
[0025] Figure 2 This is the reaction route of bis-vinyl silane. DETAILED DESCRIPTION
[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] Preparation method of pentaerythritol diphosphate diphosphoryl chloride: add 68g of pentaerythritol and 226.7mL of phosphorus oxychloride into a flask, stir and disperse, heat to 80°C, react for 12h, and after the reaction is completed, cool to room temperature, filter, wash with ethanol, and dry to obtain pentaerythritol diphosphate diphosphoryl chloride.
[0028] The defoamer is defoamer BYK025;
[0029] The leveling agent is BYK381;
[0030] The film-forming aid is diethylene glycol ethyl ether.
[0031] Example 1
[0032] (1) Under nitrogen conditions, add 10 g of diallylamine and 25 g of 3-isocyanatepropyltriethoxysilane into a flask filled with tetrahydrofuran solvent, stir and disperse, heat to 50°C, and react for 5 hours. After the reaction is completed, evaporate the solvent under reduced pressure, wash with deionized water, and dry to obtain bis-vinyl silane.
[0033] (2) Add 2.5 g of sodium dodecylbenzene diphenyl ether disulfonate emulsifier and 1.5 g of sodium bicarbonate to a flask filled with deionized water, stir and mix evenly, add 20 g of methyl methacrylate, 20 g of hydroxyethyl methacrylate, and 6 g of diene silane, stir and mix evenly, then add 3 g of potassium persulfate, heat to 80°C, react for 20 min, add dimethylethanolamine as a neutralizer, control the pH to 7, heat to 85°C, mature for 3 h, cool and discharge, filter, and obtain a modified hydroxy polyacrylate dispersion.
[0034] (3) Add 10 g of pentaerythritol diphosphate diphosphoryl chloride to a 30% acetone aqueous solution, stir and mix evenly, add 12 g of tris(hydroxymethyl)aminomethane and 20 g of triethylamine at 0°C, stir and react for 4 h, continue to heat to 60°C, react for 10 h, and after the reaction is completed, cool to room temperature, rotary evaporate, wash with chloroform, and dry to obtain a phosphorus-containing hexahydric alcohol.
[0035] (4) Under nitrogen conditions, 15 g of phosphorus-containing hexavalent alcohol and 45 g of isophorone diisocyanate were added to a flask filled with tetrahydrofuran solvent, stirred and dispersed, and then 0.04 g of dibutyltin dilaurate was added thereto. The mixture was reacted at 45° C. for 4 h. After the reaction was completed, the mixture was rotary evaporated, washed with deionized water, and dried to obtain a phosphorus-containing polyisocyanate.
[0036] (5) Add 40 g of modified hydroxy polyacrylate dispersion into a paint mixing tank, add 0.6 g of defoamer, 0.8 g of leveling agent, 2 g of film-forming aid, and 46.6 g of deionized water, stir and disperse for 20 minutes, then add 10 g of phosphorus-containing polyisocyanate, continue stirring for 40 minutes, filter, and obtain a water-based two-component polyurethane coating.
[0037] Example 2
[0038] (1) Under nitrogen conditions, add 10 g of diallylamine and 30 g of 3-isocyanatepropyltriethoxysilane into a flask filled with tetrahydrofuran solvent, stir and disperse, heat to 45°C, and react for 5 hours. After the reaction is completed, evaporate the solvent under reduced pressure, wash with deionized water, and dry to obtain bis-vinyl silane.
[0039] (2) Add 2 g of sodium dodecylbenzene diphenyl ether disulfonate emulsifier and 1.2 g of sodium bicarbonate to a flask filled with deionized water, stir and mix evenly, add 20 g of methyl methacrylate, 15 g of hydroxyethyl methacrylate, and 8 g of diene silane, stir and mix evenly, then add 2 g of potassium persulfate, heat to 80°C, react for 40 minutes, add dimethylethanolamine as a neutralizer, control the pH to 8, heat to 85°C, mature for 1.5 hours, cool and discharge, filter, and obtain a modified hydroxy polyacrylate dispersion.
[0040] (3) Add 10 g of pentaerythritol diphosphate diphosphoryl chloride to a 30% acetone aqueous solution, stir and mix evenly, add 10 g of tris(hydroxymethyl)aminomethane and 22 g of triethylamine at 10° C., stir and react for 5 h, continue to heat to 50° C., react for 12 h, and after the reaction is completed, cool to room temperature, rotary evaporate, wash with chloroform, and dry to obtain a phosphorus-containing hexahydric alcohol.
[0041] (4) Under nitrogen conditions, 15 g of phosphorus-containing hexahydric alcohol and 45 g of isophorone diisocyanate were added to a flask filled with tetrahydrofuran solvent, stirred and dispersed, and then 0.04 g of dibutyltin dilaurate was added thereto. The mixture was reacted at 50° C. for 3 h. After the reaction was completed, the mixture was rotary evaporated, washed with deionized water, and dried to obtain a phosphorus-containing polyisocyanate.
[0042] (5) Add 42 g of modified hydroxy polyacrylate dispersion into a paint mixing tank, add 0.4 g of defoamer, 0.6 g of leveling agent, 3 g of film-forming aid, and 42 g of deionized water, stir and disperse for 40 minutes, then add 12 g of phosphorus-containing polyisocyanate, continue stirring for 20 minutes, filter, and obtain a water-based two-component polyurethane coating.
[0043] Example 3
[0044] (1) Under nitrogen conditions, add 10 g of diallylamine and 28 g of 3-isocyanatepropyltriethoxysilane into a flask filled with tetrahydrofuran solvent, stir and disperse, heat to 60°C, and react for 2 hours. After the reaction is completed, evaporate the solvent under reduced pressure, wash with deionized water, and dry to obtain bis-vinyl silane.
[0045] (2) Add 1 g of sodium dodecylbenzene diphenyl ether disulfonate emulsifier and 1.8 g of sodium bicarbonate to a flask filled with deionized water, stir and mix evenly, add 20 g of methyl methacrylate, 20 g of hydroxyethyl methacrylate, and 10 g of bis(vinylsilane), stir and mix evenly, then add 1 g of potassium persulfate, heat to 80°C, react for 40 min, add dimethylethanolamine as a neutralizer, control the pH to 7, heat to 85°C, mature for 3 h, cool and discharge, filter, and obtain a modified hydroxy polyacrylate dispersion.
[0046] (3) Add 10 g of pentaerythritol diphosphate diphosphoryl chloride to a 30% acetone aqueous solution, stir and mix evenly, add 8 g of tris(hydroxymethyl)aminomethane and 24 g of triethylamine at 5°C, stir and react for 2 h, continue to heat to 55°C, react for 6 h, and after the reaction is completed, cool to room temperature, rotary evaporate, wash with chloroform, and dry to obtain a phosphorus-containing hexahydric alcohol.
[0047] (4) Under nitrogen conditions, 15 g of phosphorus-containing hexavalent alcohol and 45 g of isophorone diisocyanate were added to a flask filled with tetrahydrofuran solvent, stirred and dispersed, and then 0.06 g of dibutyltin dilaurate was added thereto. The mixture was reacted at 45° C. for 6 h. After the reaction was completed, the mixture was rotary evaporated, washed with deionized water, and dried to obtain a phosphorus-containing polyisocyanate.
[0048] (5) Add 45 g of modified hydroxy polyacrylate dispersion into a paint mixing tank, add 0.5 g of defoamer, 1 g of leveling agent, 1.5 g of film-forming aid, and 37 g of deionized water, stir and disperse for 50 minutes, then add 15 g of phosphorus-containing polyisocyanate, continue stirring for 30 minutes, filter, and obtain a water-based two-component polyurethane coating.
[0049] Example 4
[0050] (1) Under nitrogen conditions, add 10 g of diallylamine and 25 g of 3-isocyanatepropyltriethoxysilane into a flask filled with tetrahydrofuran solvent, stir and disperse, heat to 50°C, and react for 4 hours. After the reaction is completed, evaporate the solvent under reduced pressure, wash with deionized water, and dry to obtain bis-vinyl silane.
[0051] (2) Add 2 g of sodium dodecylbenzene diphenyl ether disulfonate emulsifier and 1 g of sodium bicarbonate to a flask filled with deionized water, stir and mix evenly, add 20 g of methyl methacrylate, 30 g of hydroxyethyl methacrylate, and 11 g of diene silane, stir and mix evenly, then add 2 g of potassium persulfate, heat to 80°C, react for 30 minutes, add dimethylethanolamine as a neutralizer, control the pH to 8, heat to 85°C, mature for 2 hours, cool and discharge, filter, and obtain a modified hydroxy polyacrylate dispersion.
[0052] (3) Add 10 g of pentaerythritol diphosphate diphosphoryl chloride to a 30% acetone aqueous solution, stir and mix evenly, add 10 g of tris(hydroxymethyl)aminomethane and 22 g of triethylamine at 0°C, stir and react for 4 h, continue to heat to 55°C, react for 12 h, and after the reaction is completed, cool to room temperature, rotary evaporate, wash with chloroform, and dry to obtain a phosphorus-containing hexahydric alcohol.
[0053] (4) Under nitrogen conditions, 15 g of phosphorus-containing hexavalent alcohol and 42 g of isophorone diisocyanate were added to a flask filled with tetrahydrofuran solvent, stirred and dispersed, and then 0.05 g of dibutyltin dilaurate was added thereto. The mixture was reacted at 40° C. for 6 h. After the reaction was completed, the mixture was rotary evaporated, washed with deionized water, and dried to obtain a phosphorus-containing polyisocyanate.
[0054] (5) Add 50 g of modified hydroxy polyacrylate dispersion into a paint mixing tank, add 0.6 g of defoamer, 0.8 g of leveling agent, 2.5 g of film-forming aid, and 28.1 g of deionized water, stir and disperse for 20 minutes, then add 18 g of phosphorus-containing polyisocyanate, continue stirring for 40 minutes, filter, and obtain a water-based two-component polyurethane coating.
[0055] Example 5
[0056] (1) Under nitrogen conditions, add 10 g of diallylamine and 25 g of 3-isocyanatepropyltriethoxysilane into a flask filled with tetrahydrofuran solvent, stir and disperse, heat to 50°C, and react for 4 hours. After the reaction is completed, evaporate the solvent under reduced pressure, wash with deionized water, and dry to obtain bis-vinyl silane.
[0057] (2) Add 3.7 g of sodium dodecylbenzene diphenyl ether disulfonate emulsifier and 0.35 g of sodium bicarbonate to a flask filled with deionized water, stir and mix evenly, add 20 g of methyl methacrylate, 10 g of hydroxyethyl methacrylate, and 12 g of bis-vinyl silane, stir and mix evenly, add 0.7 g of potassium persulfate, heat to 80°C, react for 20 minutes, add dimethylethanolamine as a neutralizer, control the pH to 8, heat to 85°C, mature for 3 hours, cool and discharge, filter, and obtain a modified hydroxy polyacrylate dispersion.
[0058] (3) Add 10 g of pentaerythritol diphosphate diphosphoryl chloride to a 30% acetone aqueous solution, stir and mix evenly, add 10 g of tris(hydroxymethyl)aminomethane and 22 g of triethylamine at 0°C, stir and react for 4 h, continue to heat to 55°C, react for 12 h, and after the reaction is completed, cool to room temperature, rotary evaporate, wash with chloroform, and dry to obtain a phosphorus-containing hexahydric alcohol.
[0059] (4) Under nitrogen conditions, 15 g of phosphorus-containing hexavalent alcohol and 51 g of isophorone diisocyanate were added to a flask filled with tetrahydrofuran solvent, stirred and dispersed, and then 0.01 g of dibutyltin dilaurate was added thereto. The mixture was reacted at 50° C. for 3 h. After the reaction was completed, the mixture was rotary evaporated, washed with deionized water, and dried to obtain a phosphorus-containing polyisocyanate.
[0060] (5) Add 55 g of modified hydroxy polyacrylate dispersion into a paint mixing tank, add 0.4 g of defoamer, 1 g of leveling agent, 2 g of film-forming aid, and 21.6 g of deionized water, stir and disperse for 30 minutes, then add 20 g of phosphorus-containing polyisocyanate, continue stirring for 20 minutes, filter, and obtain a water-based two-component polyurethane coating.
[0061] Comparative Example 1
[0062] The difference between this comparative example and Example 1 is that in step (2), no divinyl silane is contained.
[0063] Comparative Example 2
[0064] The difference between this comparative example and Example 1 is that in step (5), isophorone diisocyanate is used instead of phosphorus-containing polyisocyanate.
[0065] The water-based two-component polyurethane coating is coated on the tinplate, dried naturally, and then placed at 80° C. and dried for 5 hours to obtain a substrate covered with the polyurethane coating.
[0066] Refer to GB / T1733-1993 to test the water resistance of the coating.
[0067] Refer to GB / T9286-1998 to test the adhesion performance of the coating. Use a scratcher to make two vertical scratches on the coating, gently brush the scratches with a soft brush, and use a pressure-sensitive tape to perform an adhesion pull test to determine the adhesion level (1-5).
[0068] Table 1:
[0069] Water resistance time / h Adhesion grade / level Example 1 20 Level 2 Example 2 24 Level 1 Example 3 33 Level 1 Example 4 42 Level 1 Example 5 48 Level 1 Comparative Example 1 12 Level 3 Comparative Example 2 15 Level 2
[0070] As can be seen from the table, the water resistance of Examples 1-5 and Comparative Example 2 is better than that of Comparative Example 1. This is because the siloxane structure contained in Examples 1-5 and Comparative Example 2 not only has a lower surface energy and can increase the water resistance and hydrophobicity of the polyurethane coating, but also hydrolyzes and condenses into a larger cross-linked network structure, which hinders water erosion and thus improves the water resistance of the polyurethane coating. The adhesion performance of Examples 1-5 and Comparative Example 2 is better than that of Comparative Example 1. This is because the siloxane structure contained in Examples 1-5 and Comparative Example 2 can produce a chemical reaction with the substrate, which acts as a bridge to tightly adhere the polyurethane coating to the substrate, thereby improving the adhesion of the polyurethane coating.
[0071] The tensile strength of the coating was tested using a universal tensile testing machine at a tensile rate of 100 mm / min.
[0072] Referring to GB / T2408-2008, a vertical burning test was conducted on the coating film, and the coating film size was 100mm×10mm×3mm.
[0073] Table 2:
[0074] Tensile strength / MPa UL-94 Example 1 32.05 V-0 Example 2 36.11 V-0 Example 3 40.85 V-0 Example 4 43.67 V-0 Example 5 42.76 V-0 Comparative Example 1 28.09 V-1 Comparative Example 2 24.85 V-2
[0075] It can be seen from the table that the polyurethane coating prepared by the present invention has good flame retardant properties and mechanical properties.
[0076] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A water-based two-component polyurethane coating, characterized in that: The water-based two-component polyurethane coating is composed of the following components in percentage by mass: 40-55% of a modified hydroxy polyacrylate dispersion, 10-20% of a phosphorus-containing polyisocyanate, 0.4-0.6% of a defoamer, 0.6-1% of a leveling agent, 1.5-3% of a film-forming aid, and the balance is deionized water, and the sum of the percentages of the above components is 100%; The preparation method of the water-based two-component polyurethane coating is as follows: Add the modified hydroxy polyacrylate dispersion into the paint mixing tank, add defoamer, leveling agent, film-forming aid, deionized water, stir and disperse for 20-50 minutes, then add phosphorus-containing polyisocyanate, continue stirring for 20-40 minutes, filter, and obtain a water-based two-component polyurethane coating.
2. The water-based two-component polyurethane coating according to claim 1, characterized in that: The preparation method of the modified hydroxy polyacrylate dispersion is: (1) Under nitrogen conditions, diallylamine and 3-isocyanatepropyltriethoxysilane are added to a flask containing tetrahydrofuran solvent, stirred and dispersed, heated to 45-60°C, and reacted for 2-5 hours. After the reaction is completed, the solvent is evaporated under reduced pressure, washed with deionized water, and dried to obtain bis-vinyl silane; (2) Add an emulsifier and sodium bicarbonate to a flask filled with deionized water, stir and mix evenly, add methyl methacrylate, hydroxyethyl methacrylate and bis(vinylsilane) thereto, stir and mix evenly, add potassium persulfate thereto, heat to 80°C, react for 20-40 minutes, add dimethylethanolamine as a neutralizer, control the pH to 7-8, heat to 85°C, mature for 2-3 hours, cool and discharge, filter, and obtain a modified hydroxy polyacrylate dispersion.
3. The water-based two-component polyurethane coating according to claim 2, characterized in that: In the above (1), the usage ratio of diallylamine and 3-isocyanatepropyltriethoxysilane is 100g:(250-300)g.
4. The water-based two-component polyurethane coating according to claim 2, characterized in that: In the above (2), the usage ratio of methyl methacrylate, hydroxyethyl methacrylate and bis(vinyl)silane is 100 g:(50-150) g:(30-60) g.
5. The water-based two-component polyurethane coating according to claim 2, characterized in that: In the above (2), the emulsifier is sodium dodecyl benzene diphenyl oxide disulfonate, and the amount of the emulsifier used is 3-6% of the total mass of methyl methacrylate, hydroxyethyl methacrylate, and bis-alkenyl silane; the amount of potassium persulfate used is 2-5% of the total mass of methyl methacrylate, hydroxyethyl methacrylate, and bis-alkenyl silane; the amount of sodium bicarbonate used is 1-3% of the total mass of methyl methacrylate, hydroxyethyl methacrylate, and bis-alkenyl silane.
6. The water-based two-component polyurethane coating according to claim 1, characterized in that: The preparation method of the phosphorus-containing polyisocyanate is: S1. Add pentaerythritol diphosphate diphosphoryl chloride to a 30% acetone aqueous solution, stir and mix evenly, add tris(hydroxymethyl)aminomethane and triethylamine at 0-10° C., stir and react for 2-5 hours, continue to heat to 50-60° C., react for 6-12 hours, and after the reaction is completed, cool to room temperature, rotary evaporate, wash with chloroform, and dry to obtain a phosphorus-containing hexahydric alcohol; S2. Under nitrogen conditions, add the phosphorus-containing hexavalent alcohol and isophorone diisocyanate into a flask filled with tetrahydrofuran solvent, stir and disperse, then add dibutyltin dilaurate thereto, react at 40-50°C for 3-6h, after the reaction is completed, rotary evaporate, wash with deionized water, and dry to obtain the phosphorus-containing polyisocyanate.
7. The water-based two-component polyurethane coating according to claim 6, characterized in that: In the S1, the usage ratio of pentaerythritol diphosphate diphosphoryl chloride, tris(hydroxymethyl)aminomethane and triethylamine is 100 g:(80-120) g:(200-240) g.
8. The water-based two-component polyurethane coating according to claim 6, characterized in that: In the S2, the usage ratio of the phosphorus-containing hexahydric alcohol and isophorone diisocyanate is 100 g:(280-340) g.
9. The water-based two-component polyurethane coating according to claim 6, characterized in that: In the S2, the amount of dibutyltin dilaurate used is 0.02-0.1% of the total mass of the phosphorus-containing hexahydric alcohol and isophorone diisocyanate.