A high performance coating material and a method for its preparation

Abstract

This invention belongs to the field of coating technology, specifically relating to a high-performance coating material and its preparation method. The coating material comprises the following components in parts by weight: 120-140 parts of aqueous polyurethane dispersion, 8-12 parts of silica nanoparticles, 3-8 parts of micron-sized diatomaceous earth particles, 1-3 parts of graphene oxide, 0-10 parts of additives, and 0-100 parts of deionized water. This invention uses aqueous polyurethane as the matrix resin and relies on the interaction between silica nanoparticles, micron-sized diatomaceous earth particles, and graphene oxide to construct a multi-scale, multi-dimensional reinforcing network. This not only improves the density and corrosion resistance of the coating but also enables the coating to more effectively disperse stress when subjected to external forces, thus exhibiting higher hardness and scratch resistance. It has wide applications in home appliances, automobiles, construction, and oil and gas pipelines.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a high-performance coating material and its preparation method. Background Technology

[0002] Polyurethane is a polymer containing urethane characteristic groups, and its full name is polyurethane. Polyurethane is obtained by polymerizing two raw materials: di- or polyisocyanates (acting as hard segments) and polyethers or polyester glycols (acting as soft segments). These raw materials are intertwined and bonded together. Waterborne polyurethane emulsions are binary colloidal systems with water as the dispersion medium, containing little or no organic solvents. Waterborne polyurethane is a superior polymer material with many inherent properties, such as low-temperature resistance and wear resistance. It also boasts advantages such as being non-toxic, low-cost, energy-efficient, safe, and easy to store.

[0003] Waterborne polyurethane has been widely used in coatings, adhesives, rubber, and other fields. Coatings and adhesives, in particular, are widely used in the automotive, construction, industrial, timber, aerospace, military, and other sectors. In addition to these applications, the non-toxic and highly compatible properties of waterborne polyurethane make it suitable for use in the medical field. With rapid market development and continuous technological innovation, waterborne polyurethane can be applied to even more industries.

[0004] Waterborne polyurethane, as a high-performance polymer material, uses water as a solvent and is non-toxic, low-cost, safe, environmentally friendly, and has good mechanical properties, leading to its increasing application in various fields. However, it also has many drawbacks. Modifying waterborne polyurethane with nanomaterials can enhance its mechanical properties and corrosion resistance. CN121537868A discloses an environmentally friendly anti-icing coating, its preparation method, and its application, aiming to solve the problems of low efficiency, strong corrosiveness, and significant environmental pollution associated with traditional anti-icing technologies. The coating material consists of the following components: deionized water, polyvinylpyrrolidone, propylene glycol, glycerol, fumed silica, particulate silica, ethanol, potassium acetate, and waterborne polyurethane coating. This coating features good durability, environmental friendliness, and non-corrosiveness to the substrate, making it particularly suitable for equipment such as railway tracks, wind turbine blades, and cables. It will significantly improve the operation and maintenance efficiency of critical facilities and equipment, reduce maintenance costs, and has significant economic and social benefits. CN109517516A also discloses a cerium-modified bentonite-modified waterborne polyurethane coating and its preparation method, which incorporates rare earth metal ions Ce... 3+Cerium-modified bentonite is prepared by loading it onto bentonite pretreated with chitosan. The cerium-modified bentonite aqueous dispersion is then dispersed as a modified filler in anionic aliphatic waterborne polyurethane resin, with the addition of a certain amount of crosslinking agent and additives to prepare a modified coating. By mass percentage, the waterborne polyurethane resin comprises 30-60%, deionized water 20-50%, cerium-modified bentonite 1-5%, crosslinking agent 1-5%, and other additives 0.2-2%. The cerium-modified bentonite-modified waterborne polyurethane coating prepared by this invention significantly improves the adhesion of the waterborne polyurethane coating and exhibits good water resistance and corrosion resistance, making it suitable for harsh corrosive environments and showing broad application prospects in heavy-duty corrosion protection. However, the complex preparation process of the aforementioned corrosion-resistant waterborne polyurethane coating limits its industrial application. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of high cost, complicated preparation process and difficulty in industrial scale-up of waterborne polyurethane coatings in the prior art, and to propose a high-performance coating material and its preparation method. The aim is to prepare waterborne polyurethane coating materials with good corrosion resistance using a simpler process.

[0006] To achieve the above objectives, the present invention provides a high-performance coating material comprising the following components in parts by weight: The composition includes 120-140 parts of waterborne polyurethane dispersion, 8-12 parts of silica nanoparticles, 3-8 parts of micron-sized diatomaceous earth particles, 1-3 parts of graphene oxide, 0-10 parts of additives, and 0-100 parts of deionized water.

[0007] Nano-silica itself possesses high hardness and, when uniformly dispersed in polyurethane coatings, forms a rigid nanoscale framework that restricts the movement of polymer molecular chains, thereby improving the coating's resistance to deformation. However, due to the nano-size effect, the surface of nano-silica is rich in silanol groups, exhibiting extremely strong hydrophilicity and very high surface energy. In waterborne polyurethane systems, it readily aggregates through hydrogen bonding. Once aggregation occurs, the nanoparticles lose their nano-effect, and the aggregates instead become stress concentration points and preferential channels for corrosive media penetration within the coating, leading to a decrease in the coating's hardness, adhesion, and salt spray resistance.

[0008] The addition of micron-sized diatomaceous earth and graphene oxide solves the problem of easy agglomeration of nano-silica. Micron-sized diatomaceous earth has a unique nanoporous structure, while nano-silica particles have a size on the order of tens of nanometers, a difference of two orders of magnitude. This size difference allows diatomaceous earth particles to act as a micron-sized dispersion carrier; their rough surface and porous structure promote the dispersion of nano-silica, effectively preventing direct contact and agglomeration between nano-silica particles. Graphene oxide has a two-dimensional sheet structure with a lateral size generally between 1-10 μm. Its surface is rich in oxygen-containing functional groups such as hydroxyl, carboxyl, and epoxy groups, which can form hydrogen bonds with the silanol groups on the surface of nano-silica. When the three are blended, the graphene oxide sheets can be inserted between the nano-silica particles, preventing agglomeration through steric hindrance. At the same time, graphene oxide itself is prone to sheet stacking, while nano-silica particles can act as nanospacers, attaching to the surface of graphene oxide sheets and preventing them from recombinizing. This mutually anchored and spaced relationship allows the three components to form a stable hybrid structure, with a dispersion effect far superior to that of any one component used alone.

[0009] Meanwhile, as rigid nanoparticles, nano-silica, when uniformly dispersed, can form nanoscale hard points in the polyurethane matrix, effectively restricting the movement of polymer molecular chains and thus improving the surface hardness of the coating. Although diatomaceous earth particles are relatively large, their rigid porous framework structure itself possesses high mechanical strength, serving as micron-scale rigid support points and forming a "nano-micro" multi-level reinforcement structure with nano-silica. Graphene oxide, with its two-dimensional sheet structure, forms a "flexible reinforcement network" in the coating, contributing a certain degree of rigidity and connecting the dispersed nano-silica and diatomaceous earth particles into a continuous three-dimensional reinforcement framework through its sheet bridging effect. This multi-scale, multi-dimensional reinforcement network not only improves the coating's density and enhances its corrosion resistance but also allows the coating to more effectively disperse stress when subjected to external forces, thus exhibiting higher hardness and scratch resistance. Furthermore, the uniform dispersion of inorganic fillers in the coating also increases the contact area between the coating and the substrate, resulting in excellent adhesion performance in peel tests.

[0010] Preferably, the solid content of the aqueous polyurethane dispersion is 40-70%. Specifically, it can be 40%, 45%, 50%, 55%, 60%, 65%, or 70%.

[0011] Preferably, the volume average particle size (D50) of the silica nanoparticles is 20-100 nm. Specifically, the volume average particle size of the silica nanoparticles can be 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm. In particular, the volume average particle size of the silica nanoparticles is 40-70 nm. Silica nanoparticles of suitable size can both fully form a reinforced dense network and avoid agglomeration problems caused by excessively small particle sizes.

[0012] Preferably, the volume average particle size (D50) of the micron-sized diatomaceous earth particles is 1-10 µm. Specifically, the volume average particle size of the micron-sized diatomaceous earth particles can be 1 µm, 2 µm, 3 µm, 4 µm, 5 µm, 6 µm, 7 µm, 8 µm, 9 µm, or 10 µm. Particularly, the volume average particle size of the micron-sized diatomaceous earth particles is 3-7 µm. Diatomaceous earth of suitable particle size can form a scale complementarity with nano-silica and graphene oxide, constituting a multi-scale distributed reinforcing network—micron-sized diatomaceous earth particles can act as a framework providing surface roughness and mechanical anchoring points, nano-sized silica fills the voids between diatomaceous earth particles and around graphene oxide sheets, and graphene oxide, with its two-dimensional flexible structure, bridges fillers of different scales. This multi-scale distribution allows the coating to more effectively disperse stress when subjected to external forces, while simultaneously forming a complex barrier network to delay the penetration of corrosive media. Furthermore, two different particle sizes of diatomaceous earth can be blended to better leverage its size effect.

[0013] Preferably, the additive is one or more of the following: anti-settling agent, defoamer, wetting and dispersing agent, leveling agent, preservative, and antibacterial agent.

[0014] Preferably, the anti-settling agent is one or more of BYK420, BYK425, BYK430, BYK3455, and BYK190.

[0015] Preferably, the defoamer is one or more of the following: silicone defoamer, mineral oil defoamer, and polyether defoamer.

[0016] Preferably, the wetting and dispersing agent is one or more of sodium polyacrylate, ammonium polyacrylate, polyphosphate, sulfonate, polyether-modified polycarboxylate, and dodecyl sulfate.

[0017] Preferably, the high-performance coating material comprises the following components in parts by weight: The composition includes 120-140 parts of waterborne polyurethane dispersion, 9-12 parts of silica nanoparticles, 4-6 parts of micron-sized diatomaceous earth particles, 1.5-2.5 parts of graphene oxide, 1-6 parts of additives, and 50-90 parts of deionized water.

[0018] On the other hand, the present invention also provides a method for preparing a high-performance coating material, comprising the following steps: A high-performance coating material is prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, adding an aqueous polyurethane dispersion, stirring and dispersing, then adding additives and mixing uniformly again.

[0019] Beneficial effects: This invention uses waterborne polyurethane as the matrix resin, eliminating the need for coupling agent modification of fillers such as silica. It relies solely on the interaction between silica nanoparticles, micron-sized diatomaceous earth particles, and graphene oxide to prepare a high-performance anti-corrosion coating material. The addition of micron-sized diatomaceous earth and graphene oxide solves the problem of easy agglomeration of nano-silica. As rigid nanoparticles, nano-silica, after uniform dispersion, can form nanoscale hard points in the polyurethane matrix, effectively restricting the movement of polymer molecular chains and thus improving the surface hardness of the coating. Although diatomaceous earth particles are relatively large, their rigid porous framework structure itself has high mechanical strength, serving as micron-sized rigid support points and forming a "nano-micro" multi-level reinforcement structure with nano-silica. Graphene oxide, with its two-dimensional sheet structure, forms a "flexible reinforcement network" in the coating, contributing a certain degree of rigidity and connecting the dispersed nano-silica and diatomaceous earth particles into a continuous three-dimensional reinforcement framework through its sheet bridging effect. This multi-scale, multi-dimensional reinforcement network not only improves the coating's density and enhances its corrosion resistance, but also enables the coating to more effectively disperse stress when subjected to external forces, thus exhibiting higher hardness and scratch resistance. Furthermore, the uniform dispersion of inorganic fillers in the coating increases the contact area between the coating and the substrate, resulting in excellent adhesion performance in peel tests. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0021] Performance testing: Parallel experiments were conducted to test the hardness (refer to GB / T 6739-2006), film adhesion (refer to GB / T 5210-2006), and salt spray resistance (refer to GB / T 1771-2007) of the high-performance coating materials prepared in the examples and comparative examples.

[0022] Example 1 A high-performance coating material comprising the following components in parts by weight: 120 parts of waterborne polyurethane dispersion (60% solid content), 8 parts of silica nanoparticles (average particle size 40nm), 7 parts of micron-sized diatomaceous earth particles (average particle size 2µm), 3 parts of graphene oxide (lateral dimension 2μm), 0.5 parts of anti-settling agent BYK420, 2 parts of defoamer polydimethylsiloxane, 0.5 parts of wetting and dispersing agent sodium polyacrylate, and 70 parts of deionized water.

[0023] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 3H, a film adhesion of 4.3 MPa, and a salt spray resistance of 930 hours.

[0024] Example 2 A high-performance coating material comprising the following components in parts by weight: 140 parts of aqueous polyurethane dispersion (60% solid content), 12 parts of silica nanoparticles (average particle size 70nm), 3 parts of micron-sized diatomaceous earth particles (average particle size 8µm), 1 part of graphene oxide (lateral dimension 2μm), 2 parts of anti-settling agent BYK425, 0.5 parts of defoamer polydimethylsiloxane, 2 parts of wetting and dispersing agent sodium polyacrylate, and 90 parts of deionized water.

[0025] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 2H, a film adhesion of 4.8 MPa, and a salt spray resistance of 840 hours.

[0026] Example 3 A high-performance coating material comprising the following components in parts by weight: 130 parts of aqueous polyurethane dispersion (60% solid content), 10 parts of silica nanoparticles (average particle size 50nm), 8 parts of micron-sized diatomaceous earth particles (composed of two types of diatomaceous earth with average particle sizes of 3µm and 6µm respectively in a mass ratio of 1:1), 2 parts of graphene oxide (lateral dimension 2μm), 1.5 parts of anti-settling agent BYK420, 1.5 parts of defoamer polydimethylsiloxane, 1.5 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0027] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 3H, a film adhesion of 4.5 MPa, and a salt spray resistance of 910 hours.

[0028] Example 4 A high-performance coating material comprising the following components in parts by weight: 120 parts of aqueous polyurethane dispersion (60% solid content), 8.5 parts of silica nanoparticles (average particle size 50nm), 7.5 parts of micron-sized diatomaceous earth particles (average particle size 2µm), 1.2 parts of graphene oxide (lateral dimension 2μm), 0.8 parts of anti-settling agent BYK430, 0.8 parts of defoamer polydimethylsiloxane, 1.7 parts of wetting and dispersing agent sodium polyacrylate, and 75 parts of deionized water.

[0029] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 2H, a film adhesion of 4.7 MPa, and a salt spray resistance of 900 hours.

[0030] Example 5 A high-performance coating material comprising the following components in parts by weight: 130 parts of aqueous polyurethane dispersion (60% solid content), 10 parts of silica nanoparticles (average particle size 50nm), 6 parts of micron-sized diatomaceous earth particles (composed of two types of diatomaceous earth with average particle sizes of 3µm and 6µm respectively in a mass ratio of 1:1), 2 parts of graphene oxide (lateral dimension 2μm), 1.5 parts of anti-settling agent BYK420, 1.5 parts of defoamer polydimethylsiloxane, 1.5 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0031] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 3H, a film adhesion of 5.1 MPa, and a salt spray resistance of 960 hours.

[0032] Example 6 A high-performance coating material comprising the following components in parts by weight: 125 parts of aqueous polyurethane dispersion (60% solid content), 9 parts of silica nanoparticles (average particle size 80nm), 4 parts of micron-sized diatomaceous earth particles (average particle size 4µm), 1.5 parts of graphene oxide (lateral dimension 2μm), 1 part of anti-settling agent BYK430, 1 part of defoamer polydimethylsiloxane, 1 part of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0033] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 2H, a film adhesion of 5.2 MPa, and a salt spray resistance of 850 hours.

[0034] Example 7 A high-performance coating material comprising the following components in parts by weight: 130 parts of aqueous polyurethane dispersion (60% solid content), 10 parts of silica nanoparticles (average particle size 50nm), 6 parts of micron-sized diatomaceous earth particles (average particle size 3µm), 2 parts of graphene oxide (lateral dimension 2μm), 1.5 parts of anti-settling agent BYK420, 1.5 parts of defoamer polydimethylsiloxane, 1.5 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0035] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 3H, a film adhesion of 4.6 MPa, and a salt spray resistance of 890 hours.

[0036] Example 8 A high-performance coating material comprising the following components in parts by weight: The composition includes: 135 parts of aqueous polyurethane dispersion (60% solid content), 11 parts of silica nanoparticles (average particle size 40nm), 5 parts of micron-sized diatomaceous earth particles (average particle size 5µm), 2.5 parts of graphene oxide (lateral dimension 2μm), 1.7 parts of anti-settling agent BYK420, 1.1 parts of defoamer polydimethylsiloxane, 1.6 parts of wetting and dispersing agent sodium polyacrylate, and 85 parts of deionized water.

[0037] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 2H, a film adhesion of 4.4 MPa, and a salt spray resistance of 870 hours.

[0038] Example 9 A high-performance coating material comprising the following components in parts by weight: The composition includes: 135 parts of aqueous polyurethane dispersion (60% solid content), 10.5 parts of silica nanoparticles (average particle size 70 nm), 5.5 parts of micron-sized diatomaceous earth particles (average particle size 1 µm), 2.2 parts of graphene oxide (lateral dimension 2 μm), 1.3 parts of anti-settling agent BYK430, 1.3 parts of defoamer polydimethylsiloxane, 1.3 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0039] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. The coating material was tested and found to have a hardness of 2H, a film adhesion of 5.0 MPa, and a salt spray resistance of 910 hours.

[0040] Example 10 A high-performance coating material comprising the following components in parts by weight: 130 parts of aqueous polyurethane dispersion (60% solid content), 10 parts of silica nanoparticles (average particle size 50nm), 6 parts of micron-sized diatomaceous earth particles (average particle size 6µm), 2 parts of graphene oxide (lateral dimension 2μm), 1.5 parts of anti-settling agent BYK420, 1.5 parts of defoamer polydimethylsiloxane, 1.5 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0041] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 3H, a film adhesion of 4.7 MPa, and a salt spray resistance of 880 hours.

[0042] Comparative Example 1 A high-performance coating material comprising the following components in parts by weight: 130 parts of aqueous polyurethane dispersion (60% solid content), 10 parts of silica nanoparticles (average particle size 50nm), 8 parts of micron-sized diatomaceous earth particles (average particle size 6µm), 0 parts of graphene oxide (lateral dimension 2μm), 1.5 parts of anti-settling agent BYK420, 1.5 parts of defoamer polydimethylsiloxane, 1.5 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0043] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 3H, a film adhesion of 3.4 MPa, and a salt spray resistance of 680 hours.

[0044] Comparative Example 2 A high-performance coating material comprising the following components in parts by weight: 130 parts of aqueous polyurethane dispersion (60% solid content), 10 parts of silica nanoparticles (average particle size 50nm), 0 parts of micron-sized diatomaceous earth particles (average particle size 6µm), 8 parts of graphene oxide (lateral dimension 2μm), 1.5 parts of anti-settling agent BYK420, 1.5 parts of defoamer polydimethylsiloxane, 1.5 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0045] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 2H, a film adhesion of 3.6 MPa, and a salt spray resistance of 710 hours.

[0046] Comparative Example 3 A high-performance coating material comprising the following components in parts by weight: 130 parts of aqueous polyurethane dispersion (60% solid content), 10 parts of silica nanoparticles (average particle size 50nm), 2 parts of micron-sized diatomaceous earth particles (average particle size 6µm), 6 parts of graphene oxide (lateral dimension 2μm), 1.5 parts of anti-settling agent BYK420, 1.5 parts of defoamer polydimethylsiloxane, 1.5 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0047] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 3H, a film adhesion of 3.8 MPa, and a salt spray resistance of 730 hours.

[0048] Comparative Example 4 A high-performance coating material comprising the following components in parts by weight: 130 parts of waterborne polyurethane dispersion (60% solid content), 10 parts of silica nanoparticles (average particle size 50nm), 6 parts of nano-sized diatomaceous earth particles (average particle size 300nm), 2 parts of graphene oxide (lateral dimension 2μm), 1.5 parts of anti-settling agent BYK420, 1.5 parts of defoamer polydimethylsiloxane, 1.5 parts of wetting and dispersing agent sodium polyacrylate, and 80 parts of deionized water.

[0049] The preparation method of high-performance coating materials includes the following steps: A high-performance coating material was prepared by uniformly mixing silica nanoparticles, nano-sized diatomaceous earth particles, graphene oxide, and deionized water, then adding an aqueous polyurethane dispersion, stirring and dispersing, adding additives, and mixing again. Testing showed that the coating material had a hardness of 3H, a film adhesion of 3.3 MPa, and a salt spray resistance of 700 hours.

[0050] As can be seen from the above embodiments and comparative examples, this invention uses waterborne polyurethane as the matrix resin, eliminating the need for complex modification of fillers such as silica. It relies solely on the interaction between silica nanoparticles, micron-sized diatomaceous earth particles, and graphene oxide to prepare a high-performance anti-corrosion coating material. The addition of micron-sized diatomaceous earth and graphene oxide solves the problem of easy agglomeration of nano-silica. As rigid nanoparticles, nano-silica, after uniform dispersion, can form nanoscale hard points in the polyurethane matrix, effectively restricting the movement of polymer molecular chains and thus improving the surface hardness of the coating. Although diatomaceous earth particles are relatively large, their rigid porous framework structure itself has high mechanical strength and can serve as micron-sized rigid support points, forming a "nano-micro" multi-level reinforcement structure with nano-silica. Graphene oxide, with its two-dimensional sheet structure, forms a "flexible reinforcement network" in the coating, contributing a certain degree of rigidity and connecting the dispersed nano-silica and diatomaceous earth particles into a continuous three-dimensional reinforcement framework through its sheet bridging effect. This multi-scale, multi-dimensional reinforcement network not only improves the coating's density and enhances its corrosion resistance, but also enables the coating to more effectively disperse stress when subjected to external forces, thus exhibiting higher hardness and scratch resistance. Furthermore, the uniform dispersion of inorganic fillers in the coating increases the contact area between the coating and the substrate, resulting in excellent adhesion performance in peel tests.

[0051] Specifically, compared to Example 10, Comparative Examples 1 and 2 lacked micron-sized diatomaceous earth particles and graphene oxide, respectively, resulting in a significant reduction in their corrosion resistance and adhesion. This is because micron-sized diatomaceous earth possesses a unique nanoporous structure, while the particle size of nano-silica is on the order of tens of nanometers, a difference of two orders of magnitude. This size difference allows diatomaceous earth particles to act as a micron-sized dispersion carrier; their rough surface and porous structure promote the dispersion of nano-silica, effectively preventing direct contact and aggregation between nano-silica particles. Graphene oxide has a two-dimensional sheet structure with a surface rich in oxygen-containing functional groups such as hydroxyl, carboxyl, and epoxy groups. When the three are blended, the graphene oxide sheets can insert between the nano-silica particles, preventing aggregation through steric hindrance. Simultaneously, graphene oxide itself is prone to sheet stacking, while nano-silica particles can act as nanospacers, adhering to the surface of the graphene oxide sheets and preventing recombination. This mutually anchored and spaced relationship allows the three components to form a stable hybrid structure, with a dispersion effect far superior to that of any one component used alone.

[0052] Compared to Example 10, Comparative Example 3 used too few micron-sized diatomaceous earth particles and too many graphene oxide particles, resulting in little change in coating hardness but a significant decrease in salt spray resistance and adhesion. This is because the micron-sized diatomaceous earth particles act as a micron-sized dispersion carrier—using their porous structure and rough surface to provide physical anchoring points for nano-silica and graphene oxide, preventing their aggregation. When the amount of diatomaceous earth is too small, this multi-scale synergistic dispersion mechanism cannot function effectively. Graphene oxide plays a reinforcing and dispersion-assisting role in the polyurethane matrix. When the amount of graphene oxide added is moderate, its high specific surface area and abundant oxygen-containing functional groups can form strong hydrogen bond interactions with the polyurethane molecular chains. At the same time, the graphene oxide sheets themselves act as a physical barrier, effectively extending the diffusion path of corrosive media, thereby simultaneously improving mechanical properties and corrosion resistance. However, when excessive amounts of graphene oxide are added, due to the strong van der Waals forces and π-π stacking interactions between the graphene oxide sheets, the excess graphene oxide struggles to maintain uniform dispersion within the limited polyurethane matrix. Instead, it tends to recombine and form agglomerates. These agglomerates not only fail to provide isolation and dispersion but also become micron-scale defects—voids and microcracks form around them, becoming channels for the preferential penetration of corrosive media. Similarly, as shown in Comparative Example 4, when nanoscale diatomaceous earth is used, its small particle size prevents it from achieving synergistic dispersion with nano-silica and graphene oxide in terms of size and morphology, leading to reduced product performance.

[0053] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described; these embodiments not explicitly stated should also be considered within the scope of this specification. Although the present invention has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A high-performance coating material, characterized in that, It contains the following components in parts by weight: The composition includes 120-140 parts of waterborne polyurethane dispersion, 8-12 parts of silica nanoparticles, 3-8 parts of micron-sized diatomaceous earth particles, 1-3 parts of graphene oxide, 0-10 parts of additives, and 0-100 parts of deionized water.

2. The high-performance coating material as described in claim 1, characterized in that, The waterborne polyurethane dispersion has a solid content of 40-70%.

3. The high-performance coating material as described in claim 1, characterized in that, The volume average particle size of the silica nanoparticles is 20-100 nm.

4. The high-performance coating material as described in claim 1, characterized in that, The average volumetric diameter of the micron-sized diatomite particles is 1-10µm.

5. The high-performance coating material as described in claim 1, characterized in that, The additives are one or more of the following: anti-settling agents, defoamers, wetting and dispersing agents, leveling agents, preservatives, and antibacterial agents.

6. The high-performance coating material as described in claim 5, characterized in that, The anti-settling agent is one or more of BYK420, BYK425, BYK430, BYK3455, and BYK190.

7. The high-performance coating material as described in claim 5, characterized in that, The defoamer is one or more of the following: silicone defoamer, mineral oil defoamer, and polyether defoamer.

8. The high-performance coating material as described in claim 5, characterized in that, The wetting and dispersing agent is one or more of sodium polyacrylate, ammonium polyacrylate, polyphosphate, sulfonate, polyether-modified polycarboxylate, and dodecyl sulfate.

9. The high-performance coating material as described in claim 1, characterized in that, It contains the following components in parts by weight: The composition includes 120-140 parts of waterborne polyurethane dispersion, 9-12 parts of silica nanoparticles, 4-6 parts of micron-sized diatomaceous earth particles, 1.5-2.5 parts of graphene oxide, 1-6 parts of additives, and 50-90 parts of deionized water.

10. The method for preparing a high-performance coating material as described in claim 1, characterized in that, Includes the following steps: A high-performance coating material is prepared by uniformly mixing silica nanoparticles, micron-sized diatomaceous earth particles, graphene oxide, and deionized water, adding an aqueous polyurethane dispersion, stirring and dispersing, then adding additives and mixing uniformly again.