High-strength impact-resistant polyurethane floor coating and preparation method thereof

Abstract

The invention discloses a high-strength impact-resistant polyurethane floor coating and a preparation method thereof, and belongs to the technical field of floor coatings. Deionized water, a dispersing agent, filler, impact-resistant reinforced particles, a water-based hydroxy acrylic resin dispersion, a coalescing agent, a defoaming agent, a wetting agent, a flatting agent, a thickening agent, a preservative and color paste are taken and mixed to obtain a component A; mixing a water-based isocyanate curing agent and propylene glycol methyl ether acetate to serve as a component B, and mixing the component B with the component A to obtain the high-strength impact-resistant polyurethane floor coating. The anti-impact reinforced particles are polydopamine modified graphene oxide; the water-based hydroxy acrylic resin dispersion is prepared by performing semi-continuous solution polymerization on methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate and modified acrylate and then adding water for dispersion; the modified acrylate is benzene ring-containing polysiloxane grafted tripropylene glycol diacrylate, so that the strength and the impact resistance of the polyurethane floor coating are improved.

Description

Technical Field

[0001] This invention belongs to the field of floor coating technology, specifically relating to a high-strength, impact-resistant polyurethane floor coating and its preparation method. Background Technology

[0002] Polyurethane floor coatings, with their excellent wear resistance, chemical corrosion resistance, seamless integrity, and ease of application, have become a core floor protection material for industrial workshops, logistics warehouses, parking lots, and commercial buildings. As modern industrial production intensifies and logistics turnover increases, flooring must withstand the harsh effects of forklift traffic, heavy object impacts, and equipment friction over extended periods, leading to increasingly stringent requirements for high strength and impact resistance. Simultaneously, under increasingly stringent environmental policies, solvent-based polyurethane floor coatings are strictly restricted due to volatile organic compound (VOC) emissions, making water-based and low-pollution solutions an inevitable trend in the industry.

[0003] However, existing waterborne polyurethane floor coatings still have significant performance shortcomings in practical applications, making it difficult to simultaneously meet the requirements of high strength and impact resistance: Traditional waterborne polyurethane floor coatings often rely on a simple blend of polyether or polyester soft segments and isocyanate hard segments as their resin matrix. The aggregation of hard segments leads to greater coating brittleness, making it prone to cracking and peeling under external impact, resulting in insufficient impact resistance. Inorganic fillers added to improve strength (such as calcium carbonate and talc) are prone to agglomeration and have poor interfacial compatibility with the resin matrix. This not only fails to effectively enhance impact resistance but may also exacerbate coating damage due to stress concentration. Organosilicon modification is an effective way to improve the flexibility of polyurethane floor coatings. While toughness is a common challenge, existing technologies often employ physical blending to introduce silicone components. This results in poor compatibility between silicone and the polyurethane matrix, weak interfacial bonding, limited modification effects, and issues such as coating gloss loss and reduced stain resistance. Carbon-based nanomaterials (such as graphene), as highly efficient reinforcing phases, can improve coating strength, but their strong surface inertness, tendency to agglomerate, poor dispersibility with water-based resins, and weak interfacial bonding make it difficult to fully realize their impact-enhancing effects. Therefore, developing a polyurethane floor coating with high strength, excellent impact resistance, and environmentally friendly water-based properties has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength, impact-resistant polyurethane floor coating and its preparation method, thereby improving the mechanical strength and impact resistance of the polyurethane floor coating.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for preparing a high-strength, impact-resistant polyurethane floor coating includes the following steps: S1. Take deionized water, dispersant, filler, impact-reinforcing particles, waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste and mix them evenly to obtain component A; S2. Take water-based isocyanate curing agent and propylene glycol methyl ether acetate and mix them evenly as component B. Mix component B with component A evenly to obtain the high-strength impact-resistant polyurethane floor coating. The impact-resistant reinforcing particles are polydopamine-modified graphene oxide. The aqueous hydroxyl acrylic resin dispersion is prepared by semi-continuous solution polymerization of methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate and modified acrylate, followed by dispersion with water; the modified acrylate is tripropylene glycol diacrylate grafted with benzene ring polysiloxane.

[0006] As a preferred embodiment of the present invention, in step S1, the mass ratio of deionized water, dispersant, filler, impact-reinforcing particles, aqueous hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste is 12-18:0.4-0.5:7-11:2-4:55-65:1-3:0.1-0.3:0.6-0.8:0.5-0.9:0.3-0.5:0.1-0.3:1-3.

[0007] As a preferred embodiment of the present invention, in step S2, the mass ratio of the aqueous isocyanate curing agent to propylene glycol methyl ether acetate is 4-5:1.

[0008] As a preferred embodiment of the present invention, in step S2, the mass ratio of component A to component B is 5-9:2-3.

[0009] As a preferred embodiment of the present invention, the method for preparing the impact-resistant reinforcing particles includes the following steps: The graphene oxide prepared by the modified Hummers method was dispersed in Tris-HCl buffer (10 mM, pH=8.5), ultrasonically stirred, dopamine hydrochloride was added, stirred in the dark, centrifuged, the solid phase was washed, and freeze-dried under vacuum to obtain the impact-enhancing particles.

[0010] As a preferred embodiment of the present invention, the mass ratio of graphene oxide to dopamine hydrochloride is 2-3:1.

[0011] As a preferred embodiment of the present invention, the method for preparing the modified acrylate includes the following steps: A1. Styrene and methyl hydrogen silicone oil are dispersed in a solvent, a catalyst is added, and a hydrosilylation reaction is carried out to obtain a polysiloxane containing a benzene ring. A2. Mix tripropylene glycol diacrylate, solvent and catalyst evenly, and slowly add it to the benzene ring-containing polysiloxane at 55-65℃. The hydrosilylation reaction is carried out to obtain the modified acrylate.

[0012] A high-strength, impact-resistant polyurethane floor coating prepared using the above-described method.

[0013] The beneficial effects of this invention are: This invention achieves improved hardness and impact resistance of polyurethane floor coatings through the synergistic effect of toughening with flexible organosilicon segments, reinforcement with rigid benzene ring groups, and interface enhancement with polydopamine-coated graphene oxide. When the coating is subjected to impact, the flexible segments can rapidly undergo conformational changes and elastic deformation, efficiently dissipating instantaneous impact energy and preventing stress concentration that could lead to coating brittleness. In addition, the organosilicon segments can significantly reduce the internal shrinkage stress of the cured coating, improving coating toughness and substrate adhesion, thus improving impact resistance at the matrix level. The simultaneous introduction of a rigid benzene ring structure into the styrene through hydrosilylation increases the cohesive strength of the resin matrix and allows it to form strong π-π interactions with subsequent impact-reinforcing particles (polydopamine-modified graphene oxide), becoming an interfacial bridge between the resin matrix and the nanofiller, enhancing interfacial bonding stability. The three components form a stable rigid-flexible interpenetrating three-dimensional network through covalent bonds and π-π conjugation, significantly improving impact resistance while ensuring high film hardness. Detailed Implementation

[0014] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0015] A method for preparing a high-strength, impact-resistant polyurethane floor coating includes the following steps: S1. Styrene and methyl hydrogen silicone oil are dispersed in a solvent, a catalyst is added, and the reaction is carried out at 60-70℃ for 1-3 hours to obtain polysiloxane; Take tripropylene glycol diacrylate, solvent and catalyst and mix them evenly. Slowly add the mixture to the polysiloxane at 55-65℃ and keep it at the temperature for 2-4 hours. After the reaction is completed, remove the catalyst with activated carbon, filter, and take the liquid phase for vacuum distillation to obtain the modified acrylate. The mass ratio of styrene, methyl hydrogen silicone oil, the first added solvent, the first added catalyst, tripropylene glycol diacrylate, the second added solvent, and the second added catalyst is 1-1.2:2-3:15-20:0.02-0.04:1.5-3:10-20:0.01-0.02. The catalyst is a Karstedt catalyst with a platinum concentration of 2000 ppm; the methyl hydrogen-containing silicone oil has a hydrogen content of 1 wt% and a Si-H content of 0.02-0.03 mol; the solvent is isopropanol. S2. Take methyl methacrylate, butyl acrylate, acrylic acid, and hydroxyethyl methacrylate and add them to isopropanol. Then add 1 / 3 mass of azobisisobutyronitrile and 1 / 3 mass of modified acrylate. Stir at 75℃ for 30-40 min. Add the remaining azobisisobutyronitrile and modified acrylate. Cool to 50℃ and stir for 3-4 h. Then add triethylamine to adjust the pH to 7-8. Remove isopropanol by vacuum distillation. Then add deionized water under high speed stirring. Cool and discharge to obtain an aqueous hydroxyl acrylic resin dispersion. The mass ratio of methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate, isopropanol, azobisisobutyronitrile, modified acrylate, and deionized water is 18-25:10-14:10-12:8-12:50-80:1-2:6-8:76-83. S3. Add dispersant, filler and impact-reinforcing particles to deionized water, grind, disperse and stir for 5-10 minutes, while stirring, add water-based hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative and color paste, stir evenly and filter, discharge to obtain component A; The dispersant is selected from at least one of BYK163 dispersant and BYK161 dispersant; The filler is selected from at least one of silica powder, glass powder, precipitated barium sulfate, and talc. The film-forming aid is selected from at least one of dipropylene glycol methyl ether, diethylene glycol methyl ether, dipropylene glycol butyl ether, and decyl alcohol ester; The defoamer is selected from any one of polyether defoamers and polyether siloxane defoamers; The wetting agent is selected from the Tego 270 substrate wetting agent; The leveling agent is selected from either Tego Flow300 leveling agent or BYK 306 leveling agent; The thickener is selected from BYK428 thickener; The preservative is selected from at least one of methylisothiazolinone and benzisothiazolin-3-one; The colorant is selected from water-based iron yellow colorant; The mass ratio of the deionized water, dispersant, filler, impact-reinforcing particles, aqueous hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste is 12-18:0.4-0.5:7-11:2-4:55-65:1-3:0.1-0.3:0.6-0.8:0.5-0.9:0.3-0.5:0.1-0.3:1-3; S4. Take water-based isocyanate curing agent and propylene glycol methyl ether acetate and mix them evenly as component B; the mass ratio of water-based isocyanate curing agent to propylene glycol methyl ether acetate is 4-5:1; the water-based isocyanate curing agent is selected from Bayhydur XP 2547 Covestro curing agent. Mix component B and component A at a mass ratio of 5-9:2-3 until homogeneous to obtain the high-strength impact-resistant polyurethane floor coating. The method for preparing the impact-resistant reinforced particles includes the following steps: Graphene oxide prepared using the modified Hummers method was dispersed in Tris-HCl buffer (10 mM, pH=8.5), ultrasonically stirred for 20-30 min, dopamine hydrochloride was added, stirred in the dark for 24 h, centrifuged, the solid phase was washed, and freeze-dried under vacuum to obtain the impact-enhancing particles; the ratio of graphene oxide, dopamine hydrochloride, and Tris-HCl buffer was 0.2-0.3 g: 0.1 g: 200 mL.

[0016] A method for preparing a high-strength, impact-resistant polyurethane floor coating includes the following steps: S1. Styrene and methyl hydrogen silicone oil are dispersed in a solvent, a catalyst is added, and the mixture is reacted at 60°C for 3 hours to obtain polysiloxane; Tripropylene glycol diacrylate, solvent and catalyst were mixed evenly and slowly added to the polysiloxane at 55°C. The reaction was maintained at this temperature for 4 hours. After the reaction was completed, the catalyst was removed with activated carbon, filtered, and the liquid phase was distilled under reduced pressure to obtain the modified acrylate. The mass ratio of styrene, methyl hydrogen silicone oil, the first added solvent, the first added catalyst, tripropylene glycol diacrylate, the second added solvent, and the second added catalyst is 1:2:15:0.02:1.5:10:0.01. The catalyst is a Karstedt catalyst with a platinum concentration of 2000 ppm; the methyl hydrogen-containing silicone oil has a hydrogen content of 1 wt% and a Si-H content of 0.02 mol; the solvent is isopropanol. S2. Methyl methacrylate, butyl acrylate, acrylic acid, and hydroxyethyl methacrylate were added to isopropanol. Then, 1 / 3 of the mass of azobisisobutyronitrile and 1 / 3 of the mass of modified acrylate were added. The mixture was stirred at 75°C for 30 min. The remaining azobisisobutyronitrile and modified acrylate were added. The mixture was cooled to 50°C and stirred for 3 h. Then, triethylamine was added to adjust the pH to 7. Isopropanol was removed by vacuum distillation. Deionized water was added under high-speed stirring. The mixture was cooled and discharged to obtain an aqueous hydroxyl acrylic resin dispersion. The mass ratio of methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate, isopropanol, azobisisobutyronitrile, modified acrylate, and deionized water is 18:10:10:8:50:1:6:76. S3. Add dispersant, filler, and impact-reinforcing particles to deionized water, grind, disperse, and stir for 5 minutes. While stirring, add waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste. After stirring evenly, filter and discharge to obtain component A. The mass ratio of deionized water, dispersant, filler, impact-reinforcing particles, waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste is 12:0.4:7:2:55:1:0.1:0.6:0.5:0.3:0.1:1. The dispersant is BYK163 dispersant; the filler is precipitated barium sulfate; the film-forming aid is dipropylene glycol methyl ether; the defoamer is a polyether defoamer; the wetting agent is Tego 270 substrate wetting agent; the leveling agent is Tego Flow 300 leveling agent; the thickener is BYK 428 thickener; the preservative is methylisothiazolinone; and the colorant is water-based iron yellow paste. S4. Take water-based isocyanate curing agent and propylene glycol methyl ether acetate and mix them evenly as component B; the mass ratio of water-based isocyanate curing agent to propylene glycol methyl ether acetate is 4:1; the water-based isocyanate curing agent is selected from BayhydurXP 2547 Covestro curing agent; The high-strength impact-resistant polyurethane floor coating is obtained by mixing component B and component A at a mass ratio of 5:2. The method for preparing the impact-resistant reinforced particles includes the following steps: Graphene oxide prepared using the modified Hummers method was dispersed in Tris-HCl buffer (10 mM, pH=8.5), ultrasonically stirred for 20 min, dopamine hydrochloride was added, stirred in the dark for 24 h, centrifuged, the solid phase was washed, and freeze-dried under vacuum to obtain the impact-enhancing particles; the ratio of graphene oxide, dopamine hydrochloride, and Tris-HCl buffer was 0.2 g: 0.1 g: 200 mL.

[0017] Example 2 A method for preparing a high-strength, impact-resistant polyurethane floor coating includes the following steps: S1. Styrene and methyl hydrogen silicone oil are dispersed in a solvent, a catalyst is added, and the mixture is reacted at 65°C for 2 hours to obtain polysiloxane. Tripropylene glycol diacrylate, solvent and catalyst were mixed evenly and slowly added to the polysiloxane at 60°C. The reaction was kept at this temperature for 3 hours. After the reaction was completed, the catalyst was removed with activated carbon, filtered, and the liquid phase was distilled under reduced pressure to obtain the modified acrylate. The mass ratio of styrene, methyl hydrogen silicone oil, the first added solvent, the first added catalyst, tripropylene glycol diacrylate, the second added solvent, and the second added catalyst is 1.1:2.5:18:0.03:2.2:15:0.015. The catalyst is a Karstedt catalyst with a platinum concentration of 2000 ppm; the methyl hydrogen-containing silicone oil has a hydrogen content of 1 wt% and a Si-H content of 0.025 mol; the solvent is isopropanol. S2. Methyl methacrylate, butyl acrylate, acrylic acid, and hydroxyethyl methacrylate were added to isopropanol. Then, 1 / 3 of the mass of azobisisobutyronitrile and 1 / 3 of the mass of modified acrylate were added. The mixture was stirred at 75°C for 35 min. The remaining azobisisobutyronitrile and modified acrylate were added. The mixture was cooled to 50°C and stirred for 3.5 h. Then, triethylamine was added to adjust the pH to 7.5. Isopropanol was removed by vacuum distillation. Deionized water was added under high-speed stirring. The mixture was cooled and discharged to obtain an aqueous hydroxyl acrylic resin dispersion. The mass ratio of methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate, isopropanol, azobisisobutyronitrile, modified acrylate, and deionized water is 22:12:11:10:65:1.5:7:80. S3. Add dispersant, filler, and impact-reinforcing particles to deionized water, grind, disperse, and stir for 8 minutes. While stirring, add waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste. After stirring evenly, filter and discharge to obtain component A. The mass ratio of deionized water, dispersant, filler, impact-reinforcing particles, waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste is 15:0.45:9:3:60:2:0.2:0.7:0.7:0.4:0.2:2. The dispersant is BYK163 dispersant; the filler is precipitated barium sulfate; the film-forming aid is dipropylene glycol methyl ether; the defoamer is a polyether defoamer; the wetting agent is Tego 270 substrate wetting agent; the leveling agent is Tego Flow 300 leveling agent; the thickener is BYK 428 thickener; the preservative is methylisothiazolinone; and the colorant is water-based iron yellow paste. S4. Take water-based isocyanate curing agent and propylene glycol methyl ether acetate and mix them evenly as component B; the mass ratio of water-based isocyanate curing agent to propylene glycol methyl ether acetate is 4.5:1; the water-based isocyanate curing agent is selected from Bayhydur XP 2547 Covestro curing agent; The high-strength impact-resistant polyurethane floor coating is obtained by mixing component B and component A at a mass ratio of 7:2.5. The method for preparing the impact-resistant reinforced particles includes the following steps: Graphene oxide prepared using the modified Hummers method was dispersed in Tris-HCl buffer (10 mM, pH=8.5), ultrasonically stirred for 25 min, dopamine hydrochloride was added, stirred in the dark for 24 h, centrifuged, the solid phase was washed, and freeze-dried under vacuum to obtain the impact-enhancing particles; the ratio of graphene oxide, dopamine hydrochloride, and Tris-HCl buffer was 0.25 g: 0.1 g: 200 mL.

[0018] Example 3 A method for preparing a high-strength, impact-resistant polyurethane floor coating includes the following steps: S1. Styrene and methyl hydrogen silicone oil are dispersed in a solvent, a catalyst is added, and the mixture is reacted at 70°C for 1 hour to obtain polysiloxane. Tripropylene glycol diacrylate, solvent and catalyst were mixed evenly and slowly added to the polysiloxane at 65°C. The reaction was kept at this temperature for 2 hours. After the reaction was completed, the catalyst was removed with activated carbon, filtered, and the liquid phase was distilled under reduced pressure to obtain the modified acrylate. The mass ratio of styrene, methyl hydrogen silicone oil, the first added solvent, the first added catalyst, tripropylene glycol diacrylate, the second added solvent, and the second added catalyst is 1.2:3:20:0.04:3:20:0.02. The catalyst is a Karstedt catalyst with a platinum concentration of 2000 ppm; the methyl hydrogen-containing silicone oil has a hydrogen content of 1 wt% and a Si-H content of 0.03 mol; the solvent is isopropanol. S2. Methyl methacrylate, butyl acrylate, acrylic acid, and hydroxyethyl methacrylate were added to isopropanol. Then, 1 / 3 of the mass of azobisisobutyronitrile and 1 / 3 of the mass of modified acrylate were added. The mixture was stirred at 75°C for 40 min. The remaining azobisisobutyronitrile and modified acrylate were added. The mixture was cooled to 50°C and stirred for 4 h. Then, triethylamine was added to adjust the pH to 8. Isopropanol was removed by vacuum distillation. Deionized water was added under high-speed stirring. The mixture was cooled and discharged to obtain an aqueous hydroxyl acrylic resin dispersion. The mass ratio of methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate, isopropanol, azobisisobutyronitrile, modified acrylate, and deionized water is 25:14:12:12:80:2:8:83. S3. Add dispersant, filler, and impact-reinforcing particles to deionized water, grind, disperse, and stir for 10 minutes. While stirring, add waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste. After stirring evenly, filter and discharge to obtain component A. The mass ratio of deionized water, dispersant, filler, impact-reinforcing particles, waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste is 18:0.5:11:4:65:3:0.3:0.8:0.9:0.5:0.3:3. The dispersant is BYK163 dispersant; the filler is precipitated barium sulfate; the film-forming aid is dipropylene glycol methyl ether; the defoamer is a polyether defoamer; the wetting agent is Tego 270 substrate wetting agent; the leveling agent is Tego Flow 300 leveling agent; the thickener is BYK 428 thickener; the preservative is methylisothiazolinone; and the colorant is water-based iron yellow paste. S4. Take water-based isocyanate curing agent and propylene glycol methyl ether acetate and mix them evenly as component B; the mass ratio of water-based isocyanate curing agent to propylene glycol methyl ether acetate is 5:1; the water-based isocyanate curing agent is selected from BayhydurXP 2547 Covestro curing agent; The high-strength impact-resistant polyurethane floor coating is obtained by mixing component B and component A at a mass ratio of 9:3. The method for preparing the impact-resistant reinforced particles includes the following steps: Graphene oxide prepared using the modified Hummers method was dispersed in Tris-HCl buffer (10 mM, pH=8.5), ultrasonically stirred for 30 min, dopamine hydrochloride was added, stirred in the dark for 24 h, centrifuged, the solid phase was washed, and freeze-dried under vacuum to obtain the impact-enhancing particles; the ratio of graphene oxide, dopamine hydrochloride, and Tris-HCl buffer was 0.3 g: 0.1 g: 200 mL.

[0019] Comparative Example 1 The difference from Example 2 is that the impact-reinforcing particles in the polyurethane floor coating are only graphene oxide, while the amounts and operations of the other components remain unchanged.

[0020] Comparative Example 2 The difference from Example 2 is that the styrene in step S1 is replaced with methyl methacrylate, while the other amounts and operations remain unchanged.

[0021] Comparative Example 3 The difference from Example 2 is that the preparation method of this polyurethane floor coating includes the following steps: S1. Methyl methacrylate, butyl acrylate, acrylic acid, and hydroxyethyl methacrylate were added to isopropanol, and then 1 / 3 of the mass of azobisisobutyronitrile was added. The mixture was stirred at 75°C for 35 min, and the remaining azobisisobutyronitrile was added. The mixture was cooled to 50°C and stirred for 3.5 h. Then triethylamine was added to adjust the pH to 7.5. Isopropanol was removed by vacuum distillation. Deionized water was added under high-speed stirring, the mixture was cooled, and the product was discharged to obtain an aqueous hydroxyl acrylic resin dispersion. The mass ratio of methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate, isopropanol, azobisisobutyronitrile, and deionized water is 22:12:11:10:65:1.5:80. S2. Add dispersant, filler, and impact-reinforcing particles to deionized water, grind, disperse, and stir for 8 minutes. While stirring, add waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste. After stirring evenly, filter and discharge to obtain component A. The mass ratio of deionized water, dispersant, filler, impact-reinforcing particles, waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste is 15:0.45:9:3:60:2:0.2:0.7:0.7:0.4:0.2:2. The dispersant is BYK163 dispersant; the filler is precipitated barium sulfate; the film-forming aid is dipropylene glycol methyl ether; the defoamer is a polyether defoamer; the wetting agent is Tego 270 substrate wetting agent; the leveling agent is Tego Flow 300 leveling agent; the thickener is BYK 428 thickener; the preservative is methylisothiazolinone; and the colorant is water-based iron yellow paste. S3. Take water-based isocyanate curing agent and propylene glycol methyl ether acetate and mix them evenly as component B; the mass ratio of water-based isocyanate curing agent to propylene glycol methyl ether acetate is 4.5:1; the water-based isocyanate curing agent is selected from Bayhydur XP 2547 Covestro curing agent; The high-strength impact-resistant polyurethane floor coating is obtained by mixing component B and component A at a mass ratio of 7:2.5. The method for preparing the impact-resistant reinforced particles includes the following steps: Graphene oxide prepared using the modified Hummers method was dispersed in Tris-HCl buffer (10 mM, pH=8.5), ultrasonically stirred for 25 min, dopamine hydrochloride was added, stirred in the dark for 24 h, centrifuged, the solid phase was washed, and freeze-dried under vacuum to obtain the impact-enhancing particles; the ratio of graphene oxide, dopamine hydrochloride, and Tris-HCl buffer was 0.25 g: 0.1 g: 200 mL.

[0022] Performance testing The hardness and impact resistance of the floor coatings obtained in Examples 1-3 and Comparative Examples 1-3 were tested in accordance with the standard GB / T 22374-2018 "Floor Coating Materials". The results are shown in Table 1.

[0023] Table 1 As shown in Table 1, the polyurethane floor coatings prepared in Examples 1-3 of this invention have better hardness and impact resistance compared to the comparative examples.

[0024] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a high-strength, impact-resistant polyurethane floor coating, characterized in that, Includes the following steps: S1. Take deionized water, dispersant, filler, impact-reinforcing particles, waterborne hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste and mix them evenly to obtain component A; S2. Take water-based isocyanate curing agent and propylene glycol methyl ether acetate and mix them evenly as component B. Mix component B with component A evenly to obtain the high-strength impact-resistant polyurethane floor coating. The impact-resistant reinforcing particles are polydopamine-modified graphene oxide. The aqueous hydroxyl acrylic resin dispersion is prepared by semi-continuous solution polymerization of methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate and modified acrylate, followed by dispersion with water; the modified acrylate is tripropylene glycol diacrylate grafted with benzene ring polysiloxane.

2. The method for preparing a high-strength impact-resistant polyurethane floor coating according to claim 1, characterized in that, In step S1, the mass ratio of deionized water, dispersant, filler, impact-reinforcing particles, aqueous hydroxyl acrylic resin dispersion, film-forming aid, defoamer, wetting agent, leveling agent, thickener, preservative, and color paste is 12-18:0.4-0.5:7-11:2-4:55-65:1-3:0.1-0.3:0.6-0.8:0.5-0.9:0.3-0.5:0.1-0.3:1-3.

3. The method for preparing a high-strength impact-resistant polyurethane floor coating according to claim 1, characterized in that, In step S2, the mass ratio of the aqueous isocyanate curing agent to propylene glycol methyl ether acetate is 4-5:

1.

4. The method for preparing a high-strength impact-resistant polyurethane floor coating according to claim 1, characterized in that, In step S2, the mass ratio of component A to component B is 5-9:2-3.

5. The method for preparing a high-strength impact-resistant polyurethane floor coating according to claim 1, characterized in that, The method for preparing the impact-resistant reinforced particles includes the following steps: The graphene oxide prepared by the modified Hummers method was dispersed in Tris-HCl buffer (10 mM, pH=8.5), ultrasonically stirred, dopamine hydrochloride was added, stirred in the dark, centrifuged, the solid phase was washed, and freeze-dried under vacuum to obtain the impact-enhancing particles.

6. The method for preparing a high-strength impact-resistant polyurethane floor coating according to claim 5, characterized in that, The mass ratio of graphene oxide to dopamine hydrochloride is 2-3:

1.

7. The method for preparing a high-strength impact-resistant polyurethane floor coating according to claim 1, characterized in that, The method for preparing the modified acrylate includes the following steps: A1. Styrene and methyl hydrogen silicone oil are dispersed in a solvent, a catalyst is added, and a hydrosilylation reaction is carried out to obtain a polysiloxane containing a benzene ring. A2. Mix tripropylene glycol diacrylate, solvent and catalyst evenly, and slowly add it to the benzene ring-containing polysiloxane at 55-65℃. The hydrosilylation reaction is carried out to obtain the modified acrylate.

8. A high-strength, impact-resistant polyurethane floor coating prepared by the preparation method according to any one of claims 1-7.

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