Anticorrosive powder coating based on nanohybrids and process for its production

Abstract

The application discloses a kind of anticorrosive powder coating based on nanohybrid and production process thereof, and relates to the technical field of powder coating.The weight parts include: 40-50 parts of epoxy resin, 5-8 parts of curing agent, 5-10 parts of nanohybrid, 2-5 parts of synergistic component, 10-15 parts of pigment and filler, 1-3 parts of coupling agent and 2-5 parts of auxiliary agent.The epoxy resin is compounded with E12, NPES-901 and epoxy-based fluorine-containing polyaryletherketone, the curing agent is a ternary compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene and isophthalic acid dihydrazide, the nanohybrid is prepared by modifying halloysite nanotube, fluorinated graphene and organic montmorillonite with silane coupling agent and ionic liquid, and the synergistic component is a compound of nano-hydroxyapatite and nano-zirconium dioxide.The synergistic effect of each component of the application makes the coating dense, with strong adhesion, wear resistance and weather resistance, and outstanding corrosion resistance, solving the problems of traditional coating, such as difficult to balance corrosion resistance and wear resistance, poor processability, etc.

Description

Technical Field

[0001] This invention relates to the field of powder coating technology, and in particular to an anti-corrosion powder coating based on nano-hybrids and its production process. Background Technology

[0002] Anti-corrosion coatings are an important means of protecting metal materials from environmental corrosion and extending their service life. Traditional solvent-based anti-corrosion coatings contain a large amount of volatile organic compounds, which pose hazards to the environment and human health. With increasingly stringent environmental regulations, powder coatings, due to their solvent-free, pollution-free, and excellent film performance, are gradually becoming the development direction in the field of corrosion protection. However, traditional epoxy powder coatings have drawbacks such as high brittleness, insufficient weather resistance, and high energy consumption for high-temperature curing. They also have poor coverage of complex areas such as corners and welds, making it difficult to meet the long-term protection requirements in harsh corrosive environments.

[0003] To improve the corrosion resistance of powder coatings, nanotechnology has been introduced into coating systems. Inorganic nanomaterials such as nano-silica and nano-zinc oxide, due to their small size and surface effects, can effectively fill coating pores and extend the penetration path of corrosive media. However, nanomaterials have large specific surface areas and high surface energies, making them prone to agglomeration during the melt extrusion process of powder coatings, leading to uneven dispersion. Simultaneously, the poor interfacial compatibility between nanomaterials and organic resin matrices easily leads to stress concentration at the interface, which in turn becomes a channel for rapid corrosion propagation. Existing technologies often use silane coupling agents to modify the surface of nanomaterials, but a single coupling agent is insufficient to achieve multiple bonds between organic and inorganic phases, resulting in significant attenuation of interfacial bonding after long-term service. Furthermore, commercially available nano-hybrid-based anti-corrosion powder coatings also suffer from various technical defects, including insufficient impact resistance, poor adhesion, and limited corrosion resistance.

[0004] For example, invention patent document CN121086632B discloses a special nano-powder coating for ultra-long-lasting anti-corrosion of ships, its preparation method, and its application. The preparation method of the aforementioned special nano-powder coating for ultra-long-lasting anti-corrosion of ships involves: placing epoxy resin, graphene-modified epoxy resin, core-shell structured ZnO@SiO2, modified 2,5-dimercapto-1,3,4-thiadiazole, borosilicate glass powder, flake boron nitride, silane coupling agent-modified silica, phenolic amine curing agent, 2-ethyl-4-methylimidazolium, fumed silica, defoamer, ultraviolet absorber, and high-temperature pigment into a mixer and stirring for 20-30 minutes. Then, the mixture is melt-extruded through a twin-screw extruder at an extrusion temperature of 90-110℃. After grinding and sieving, the special nano-powder coating for ultra-long-lasting anti-corrosion of ships is obtained. The coating prepared by this invention has good anti-corrosion performance and can be applied in the field of anti-corrosion of ship metal surfaces. However, its impact resistance still needs further improvement.

[0005] Therefore, developing a nano-hybrid-based anti-corrosion powder coating and its production process with significant anti-corrosion effect, good impact resistance, strong adhesion and long service life has become an urgent technical problem to be solved in this field. Summary of the Invention

[0006] In view of the above, the present invention aims to provide an anti-corrosion powder coating based on nano-hybrids with significant anti-corrosion effect, good impact resistance, strong adhesion and long service life, as well as its production process.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: an anti-corrosion powder coating based on nano-hybrids, comprising the following components by weight: 40-50 parts epoxy resin, 5-8 parts curing agent, 5-10 parts nano-hybrids, 2-5 parts synergistic components, 10-15 parts pigments and fillers, 1-3 parts coupling agent, and 2-5 parts additives; wherein the epoxy resin is a compound of E12 solid epoxy resin, NPES-901 solid epoxy resin, and epoxy-based fluorinated polyarylether ketone in a mass ratio of 1:(1-2):(0.1-0.3).

[0008] Preferably, the epoxy-based fluorinated polyarylether ketone is prepared according to the method in Example 1 of Chinese Patent Document CN118359805A.

[0009] Preferably, the curing agent is a compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene, and isophthalic acid dihydrazide in a mass ratio of (3-5):1:(0.8-1.2).

[0010] Preferably, the preparation method of the nano-hybrid includes the following steps: halloysite nanotubes, fluorinated graphene, and organomontmorillonite are uniformly dispersed in an organic solvent, then N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is added to the solvent, and the mixture is stirred at 60-80°C for 3-5 hours. After removing the solvent by rotary evaporation, the mixture is added to an aqueous solution of 1-ethyl-3-methylimidazolium iodide with a mass percentage concentration of 10-20%, and the mixture is stirred at 50-70°C for 8-10 hours. After centrifugation, washing, and drying, the nano-hybrid is obtained.

[0011] Preferably, the mass ratio of halloysite nanotubes, fluorinated graphene, organomontmorillonite, organic solvent, and N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is (0.1-0.3):0.5:(2-3):(15-20):(0.1-0.3).

[0012] Preferably, the molar ratio of N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt to 1-ethyl-3-methylimidazolium iodide is 1:3.

[0013] Preferably, the halloysite nanotubes have a diameter of 50-300 nm and a length of 1-10 μm; the fluorinated graphene has a fluorine content of 60%, a sheet diameter of 1-5 μm, and a thickness of 5-10 nm, and is provided by Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., item number 106790, part number XF225; the organomontmorillonite is Fenghong DK2 polymer-grade organomontmorillonite.

[0014] Preferably, the synergistic component is a mixture of nano-hydroxyapatite and nano-zirconium dioxide in a mass ratio of (1-3):1; the average particle size of the synergistic component is 20-80 nm.

[0015] Preferably, the pigment and filler are compounded from rutile titanium dioxide, precipitated barium sulfate, and mica powder in a mass ratio of (1-2):1:(0.8-1.2).

[0016] Preferably, the average particle size of the pigments and fillers is 500-1500 mesh.

[0017] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0018] Preferably, the additives are leveling agents, degassing agents, and anti-caking agents compounded in a mass ratio of (1-2):1:(0.8-1.2); the leveling agent is BYK-333; the anti-caking agent is fumed silica AEROSIL®200; and the degassing agent is benzoin.

[0019] Another objective of this invention is to provide a production process for the aforementioned anti-corrosion powder coating based on nano-hybrids, comprising the following steps: mixing the components evenly to obtain a mixture; transferring the mixture to a twin-screw extruder for extrusion granulation, followed by crushing and sieving to obtain the anti-corrosion powder coating based on nano-hybrids.

[0020] Preferably, the extrusion temperature of the twin-screw extruder is 110℃~140℃; the sieving is performed through a 100-150 mesh sieve.

[0021] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The anti-corrosion powder coating and production process based on nano-hybrids disclosed in this invention are composed of E12 solid epoxy resin, NPES-901 solid epoxy resin and epoxy-based fluorinated polyarylether ketone in a mass ratio of 1:(1-2):(0.1-0.3). E12 solid epoxy resin and NPES-901 solid epoxy resin work together to form a basic film. E12 has excellent mechanical strength and adhesion, while NPES-901 improves the melt flowability of the system and ensures the processing stability of the powder coating extrusion and film formation. Epoxy-based fluorinated polyarylether ketone is a key modifying component. The epoxy groups in its molecular structure undergo cross-linking reaction with the first two epoxy resins and curing agent to enhance the density of the coating. At the same time, the fluorinated groups can significantly improve the corrosion resistance, weather resistance and hydrophobicity of the coating. The three work together to achieve a comprehensive improvement in "processability-mechanical properties-corrosion resistance". In the prior art, epoxy-based fluorinated polyarylether ketones have not been applied to the compounding system of this type of powder coating. The present invention, through the above-mentioned compounded epoxy resin system, overcomes the technical obstacles of poor compatibility between fluorinated polymer materials and epoxy resins, high difficulty in melt processing, and inability to adapt to the extrusion process of powder coatings. At the same time, it overcomes the technical pain points of traditional powder coatings such as insufficient anti-corrosion performance, poor weather resistance, and easy aging and peeling of coatings, filling the application gap of fluorinated polyarylether ketones in the field of powder coatings.

[0022] (2) The anti-corrosion powder coating and production process based on nano-hybrids disclosed in this invention, wherein the curing agent is a compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene, and isophthalic acid dihydrazide in a mass ratio of (3-5):1:(0.8-1.2); the compound system achieves complementary and optimized performance through the synergistic effect of the three. Dicyandiamide, as the main curing agent, undertakes the core cross-linking and curing function. Its reactivity with the epoxy resin system is moderate, which can match the extrusion process of this invention, avoid pre-curing leading to extrusion difficulties, and at the same time ensure the basic cross-linking density and adhesion of the coating. It is the foundation of the curing system. Without it, the coating cannot be effectively cured, resulting in the coating failing to form a film. 9,9-bis(4-aminophenyl)fluorene, as a modified curing agent, can significantly improve the mechanical strength, temperature resistance, and aging resistance of the cured coating by introducing the rigid aromatic ring in its molecular structure, solving the problem of brittleness and easy cracking of the coating after curing with traditional curing agents. Without it, the coating cannot be effectively cured. The coating's mechanical properties are insufficient, making it unsuitable for complex working conditions. Diazyl isophthalate, as an auxiliary curing agent, can regulate the reaction rate of the entire curing system. It synergistically regulates the crosslinking reaction process with dicyandiamide and 9,9-bis(4-aminophenyl)fluorene, avoiding both excessively fast curing rates that lead to defects such as bubbles and pinholes, and excessively slow curing rates that affect production efficiency. Simultaneously, its own hydrazine group can synergistically interact with epoxy resin and nano-hybrids, further enhancing coating density and improving corrosion resistance. Without this group, the curing reaction is difficult to control stably, leading to increased coating defects and a significant decrease in corrosion resistance. Existing technologies often use single curing agents or simple binary compound curing agents, failing to achieve simultaneous improvement in "processing compatibility, mechanical properties, and corrosion resistance." This invention constructs a highly efficient and synergistic curing system through a specific ratio of these three components, specifically addressing the technical pain points of poor compatibility and uneven coating performance caused by single curing agents.

[0023] (3) The anti-corrosion powder coating and production process based on nano-hybrids disclosed in this invention, wherein the preparation method of the nano-hybrids includes the following steps: halloysite nanotubes, fluorinated graphene and organomontmorillonite are uniformly dispersed in an organic solvent, then N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is added to it, and the mixture is stirred and reacted at 60-80℃ for 3-5h. After removing the solvent by rotary evaporation, the mixture is added to an aqueous solution of 1-ethyl-3-methylimidazolium iodide with a mass percentage concentration of 10-20%, and the mixture is stirred and reacted at 50-70℃ for 8-10h. After centrifugation, washing and drying, the nano-hybrids are obtained. This nanohybrid uses halloysite nanotubes, fluorinated graphene, and organomontmorillonite as its core components. Through modification with sodium N-(trimethoxysilylpropyl)ethylenediaminetriacetate and further functionalization with 1-ethyl-3-methylimidazolium iodide, it not only solves the technical problems of poor dispersibility, insufficient compatibility with epoxy resin systems, and easy agglomeration of single nanomaterials, but also achieves synergistic effects of the three nanomaterials. Its performance far exceeds that of single nanomaterials or simple mixed systems. Specifically, the tubular structure of halloysite nanotubes can construct a "physical barrier" within the coating, hindering the penetration of corrosive media. The high fluorine content of fluorinated graphene further enhances the hydrophobicity and corrosion resistance of the coating. Organomontmorillonite can improve the compatibility of the hybrid with the resin and the density of the coating. After specific process modification, the three components synergistically form a multi-layered anti-corrosion system of "physical barrier - hydrophobic protection - improved compatibility." Compared with the addition of a single nanomaterial, this hybrid can significantly extend the salt spray test pass time of the coating, while significantly improving the adhesion, wear resistance, and weather resistance of the coating, effectively solving the technical pain points of traditional powder coatings that are easily penetrated by corrosive media and have a short service life. In addition, the preparation process is simple and controllable. The modified nano-hybrid can stably adapt to the melt extrusion process of this invention, without problems such as extrusion difficulties and coating defects caused by agglomeration. It takes into account the simultaneous improvement of processing performance and anti-corrosion performance, and its comprehensive technical effect far exceeds that of conventional nano-modified materials in the prior art.

[0024] (4) The anti-corrosion powder coating and production process based on nano-hybrids disclosed in this invention, wherein the synergistic component is composed of nano-hydroxyapatite and nano-zirconia in a mass ratio of (1-3):1; the synergistic component is compounded with two nano-inorganic functional materials in a specific ratio to form a multi-level complementary reinforcement with epoxy resin, curing agent and nano-hybrids in the system. A three-dimensional synergistic structure of "interface strengthening-bulk strengthening-corrosion barrier" is formed inside the coating, which significantly improves the mechanical strength of the coating and further extends the penetration path of corrosive media, so that the salt spray resistance, weather resistance and service life of the coating are improved simultaneously. It effectively overcomes the technical problems of conventional anti-corrosion coatings that are difficult to balance wear resistance and corrosion resistance, easy wear and peeling of coatings and poor long-term stability, and provides a synergistic gain that traditional single filler cannot achieve for the improvement of the overall performance of coatings. Detailed Implementation

[0025] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0026] Example 1: An anti-corrosion powder coating based on nano-hybrids, comprising the following components by weight: 40 parts epoxy resin, 5 parts curing agent, 5 parts nano-hybrids, 2 parts synergistic components, 10 parts pigments and fillers, 1 part coupling agent, and 2 parts additives; wherein the epoxy resin is a compound of E12 solid epoxy resin, NPES-901 solid epoxy resin, and epoxy-based fluorinated polyarylether ketone in a mass ratio of 1:1:0.1.

[0027] The epoxy-based fluorinated polyarylether ketone is prepared according to the method in Example 1 of the invention patent document CN118359805A; the curing agent is a compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene, and isophthalic acid dihydrazide in a mass ratio of 3:1:0.8.

[0028] The preparation method of the nano-hybrid includes the following steps: halloysite nanotubes, fluorinated graphene, and organomontmorillonite are uniformly dispersed in an organic solvent; then, N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is added; the mixture is stirred at 60°C for 3 hours; after removing the solvent by rotary evaporation, the mixture is added to a 10% (w / w) aqueous solution of 1-ethyl-3-methylimidazolium iodide; the mixture is stirred at 50°C for 8 hours; after centrifugation, washing, and drying, the nano-hybrid is obtained. The halloysite nanotubes, fluorinated graphene, organomontmorillonite, organic solvent, and N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt are used. The mass ratio of sodium triacetate is 0.1:0.5:2:15:0.1; the molar ratio of N-(trimethoxysilylpropyl)ethylenediaminetriacetate sodium salt to 1-ethyl-3-methylimidazolium iodide is 1:3; the halloysite nanotubes have a diameter of 50-300 nm and a length of 1-10 μm; the fluorinated graphene has a fluorine content of 60%, a sheet diameter of 1-5 μm, and a thickness of 5-10 nm, and is provided by Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., item number 106790, part number XF225; the organomontmorillonite is Fenghong DK2 polymer-grade organomontmorillonite.

[0029] The synergistic component is composed of nano-hydroxyapatite and nano-zirconium dioxide in a mass ratio of 1:1; the average particle size of the synergistic component is 20 nm; the pigment and filler are composed of rutile titanium dioxide, precipitated barium sulfate, and mica powder in a mass ratio of 1:1:0.8; the average particle size of the pigment and filler is 500 mesh; the coupling agent is silane coupling agent KH550; the additives are composed of leveling agent, degassing agent, and anti-caking agent in a mass ratio of 1:1:0.8; the leveling agent is BYK-333; the anti-caking agent is fumed silica AEROSIL®200; and the degassing agent is benzoin.

[0030] A production process for the anti-corrosion powder coating based on nano-hybrids includes the following steps: mixing the components evenly to obtain a mixture; transferring the mixture to a twin-screw extruder for extrusion granulation, followed by crushing and sieving to obtain the anti-corrosion powder coating based on nano-hybrids; the extrusion temperature of the twin-screw extruder is 110°C; and the sieving is performed through a 100-mesh sieve.

[0031] Example 2: An anti-corrosion powder coating based on nano-hybrids, comprising the following components by weight: 43 parts epoxy resin, 6 parts curing agent, 6 parts nano-hybrids, 3 parts synergistic components, 12 parts pigments and fillers, 1.5 parts coupling agent, and 3 parts additives; wherein the epoxy resin is a compound of E12 solid epoxy resin, NPES-901 solid epoxy resin, and epoxy-based fluorinated polyarylether ketone in a mass ratio of 1:1.3:0.15.

[0032] The epoxy-based fluorinated polyarylether ketone is prepared according to the method in Example 1 of the invention patent document CN118359805A; the curing agent is a compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene, and isophthalic acid dihydrazide in a mass ratio of 3.5:1:0.9.

[0033] The preparation method of the nano-hybrid includes the following steps: halloysite nanotubes, fluorinated graphene, and organomontmorillonite are uniformly dispersed in an organic solvent; then, N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is added; the mixture is stirred at 65°C for 3.5 h; after removing the solvent by rotary evaporation, the mixture is added to an aqueous solution of 13% (w / w) 1-ethyl-3-methylimidazolium iodide; the mixture is stirred at 55°C for 8.5 h; after centrifugation, washing, and drying, the nano-hybrid is obtained. The halloysite nanotubes, fluorinated graphene, organomontmorillonite, organic solvent, and N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt are present. The mass ratio of sodium triacetate is 0.15:0.5:2.3:17:0.15; the molar ratio of N-(trimethoxysilylpropyl)ethylenediaminetriacetate sodium salt to 1-ethyl-3-methylimidazolium iodide is 1:3; the halloysite nanotubes have a diameter of 50-300 nm and a length of 1-10 μm; the fluorinated graphene has a fluorine content of 60%, a sheet diameter of 1-5 μm, and a thickness of 5-10 nm, and is provided by Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., item number 106790, part number XF225; the organomontmorillonite is Fenghong DK2 polymer-grade organomontmorillonite.

[0034] The synergistic component is a mixture of nano-hydroxyapatite and nano-zirconium dioxide in a mass ratio of 1.5:1; the average particle size of the synergistic component is 40 nm; the pigment and filler are a mixture of rutile titanium dioxide, precipitated barium sulfate, and muscovite powder in a mass ratio of 1.3:1:0.9; the average particle size of the pigment and filler is 700 mesh; the coupling agent is silane coupling agent KH560; the additives are a mixture of leveling agent, degassing agent, and anti-caking agent in a mass ratio of 1.3:1:0.9; the leveling agent is BYK-333; the anti-caking agent is fumed silica AEROSIL®200; and the degassing agent is benzoin.

[0035] A production process for the anti-corrosion powder coating based on nano-hybrids includes the following steps: mixing the components evenly to obtain a mixture; transferring the mixture to a twin-screw extruder for extrusion granulation, followed by crushing and sieving to obtain the anti-corrosion powder coating based on nano-hybrids; the extrusion temperature of the twin-screw extruder is 120°C; and the sieving is through a 120-mesh sieve.

[0036] Example 3: An anti-corrosion powder coating based on nano-hybrids, comprising the following components by weight: 45 parts epoxy resin, 6.5 parts curing agent, 7 parts nano-hybrids, 3.5 parts synergistic components, 13 parts pigments and fillers, 2 parts coupling agent, and 3.5 parts additives; wherein the epoxy resin is a compound of E12 solid epoxy resin, NPES-901 solid epoxy resin, and epoxy-based fluorinated polyarylether ketone in a mass ratio of 1:1.5:0.2.

[0037] The epoxy-based fluorinated polyarylether ketone is prepared according to the method in Example 1 of the invention patent document CN118359805A; the curing agent is a compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene, and isophthalic acid dihydrazide in a mass ratio of 4:1:1.

[0038] The preparation method of the nano-hybrid includes the following steps: halloysite nanotubes, fluorinated graphene, and organomontmorillonite are uniformly dispersed in an organic solvent; then, N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is added; the mixture is stirred at 70°C for 4 hours; after removing the solvent by rotary evaporation, the mixture is added to a 15% (w / w) aqueous solution of 1-ethyl-3-methylimidazolium iodide; the mixture is stirred at 60°C for 9 hours; after centrifugation, washing, and drying, the nano-hybrid is obtained; wherein the halloysite nanotubes, fluorinated graphene, organomontmorillonite, organic solvent, and N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt are present. The mass ratio of sodium triacetate is 0.2:0.5:2.5:18:0.2; the molar ratio of N-(trimethoxysilylpropyl)ethylenediaminetriacetate sodium salt to 1-ethyl-3-methylimidazolium iodide is 1:3; the halloysite nanotubes have a diameter of 50-300 nm and a length of 1-10 μm; the fluorinated graphene has a fluorine content of 60%, a sheet diameter of 1-5 μm, and a thickness of 5-10 nm, and is provided by Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., item number 106790, part number XF225; the organomontmorillonite is Fenghong DK2 polymer-grade organomontmorillonite.

[0039] The synergistic component is composed of nano-hydroxyapatite and nano-zirconium dioxide in a mass ratio of 2:1; the average particle size of the synergistic component is 50 nm; the pigment and filler are composed of rutile titanium dioxide, precipitated barium sulfate, and mica powder in a mass ratio of 1.5:1:1; the average particle size of the pigment and filler is 1000 mesh; the coupling agent is silane coupling agent KH570; the auxiliary agent is composed of leveling agent, degassing agent, and anti-caking agent in a mass ratio of 1.5:1:1; the leveling agent is BYK-333; the anti-caking agent is fumed silica AEROSIL®200; and the degassing agent is benzoin.

[0040] A production process for the anti-corrosion powder coating based on nano-hybrids includes the following steps: mixing the components evenly to obtain a mixture; transferring the mixture to a twin-screw extruder for extrusion granulation, followed by crushing and sieving to obtain the anti-corrosion powder coating based on nano-hybrids; the extrusion temperature of the twin-screw extruder is 130°C; and the sieving is through a 140-mesh sieve.

[0041] Example 4: An anti-corrosion powder coating based on nano-hybrids, comprising the following components by weight: 48 parts epoxy resin, 7.5 parts curing agent, 9 parts nano-hybrids, 4.5 parts synergistic components, 14 parts pigments and fillers, 2.5 parts coupling agent, and 4.5 parts additives; wherein the epoxy resin is a compound of E12 solid epoxy resin, NPES-901 solid epoxy resin, and epoxy-based fluorinated polyarylether ketone in a mass ratio of 1:1.8:0.25.

[0042] The epoxy-based fluorinated polyarylether ketone is prepared according to the method in Example 1 of the invention patent document CN118359805A; the curing agent is a compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene, and isophthalic acid dihydrazide in a mass ratio of 4.5:1:1.1.

[0043] The preparation method of the nano-hybrid includes the following steps: halloysite nanotubes, fluorinated graphene, and organomontmorillonite are uniformly dispersed in an organic solvent; then, N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is added; the mixture is stirred at 75°C for 4.5 h; after removing the solvent by rotary evaporation, an aqueous solution of 18% (w / w) 1-ethyl-3-methylimidazolium iodide is added; the mixture is stirred at 65°C for 9.5 h; after centrifugation, washing, and drying, the nano-hybrid is obtained; the halloysite nanotubes, fluorinated graphene, organomontmorillonite, organic solvent, and N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt are added. The mass ratio of sodium triamine triacetate is 0.25:0.5:2.8:19:0.25; the molar ratio of sodium N-(trimethoxysilylpropyl)ethylenediamine triacetate to 1-ethyl-3-methylimidazolium iodide is 1:3; the halloysite nanotubes have a diameter of 50-300 nm and a length of 1-10 μm; the fluorinated graphene has a fluorine content of 60%, a sheet diameter of 1-5 μm, and a thickness of 5-10 nm, and is provided by Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., item number 106790, part number XF225; the organomontmorillonite is Fenghong DK2 polymer-grade organomontmorillonite.

[0044] The synergistic component is a mixture of nano-hydroxyapatite and nano-zirconium dioxide in a mass ratio of 2.5:1; the average particle size of the synergistic component is 70 nm. The pigment and filler are a mixture of rutile titanium dioxide, precipitated barium sulfate, and mica powder in a mass ratio of 1.8:1:1.1; the average particle size of the pigment and filler is 1400 mesh. The coupling agent is a mixture of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 in a mass ratio of 1:2:1. The additives are a mixture of leveling agent, degassing agent, and anti-caking agent in a mass ratio of 1.8:1:1.1; the leveling agent is BYK-333; the anti-caking agent is fumed silica AEROSIL®200; and the degassing agent is benzoin.

[0045] A production process for the anti-corrosion powder coating based on nano-hybrids includes the following steps: mixing the components evenly to obtain a mixture; transferring the mixture to a twin-screw extruder for extrusion granulation, followed by crushing and sieving to obtain the anti-corrosion powder coating based on nano-hybrids; the extrusion temperature of the twin-screw extruder is 135°C; and the sieving is through a 140-mesh sieve.

[0046] Example 5: An anti-corrosion powder coating based on nano-hybrids, comprising the following components by weight: 50 parts epoxy resin, 8 parts curing agent, 10 parts nano-hybrids, 5 parts synergistic components, 15 parts pigments and fillers, 3 parts coupling agent, and 5 parts additives; wherein the epoxy resin is a compound of E12 solid epoxy resin, NPES-901 solid epoxy resin, and epoxy-based fluorinated polyarylether ketone in a mass ratio of 1:2:0.3.

[0047] The epoxy-based fluorinated polyarylether ketone is prepared according to the method in Example 1 of the invention patent document CN118359805A; the curing agent is a compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene, and isophthalic acid dihydrazide in a mass ratio of 5:1:1.2.

[0048] The preparation method of the nano-hybrid includes the following steps: halloysite nanotubes, fluorinated graphene, and organomontmorillonite are uniformly dispersed in an organic solvent; then, N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is added; the mixture is stirred at 80°C for 5 hours; after removing the solvent by rotary evaporation, the mixture is added to an aqueous solution of 1-ethyl-3-methylimidazolium iodide with a mass percentage concentration of 20%; the mixture is stirred at 70°C for 10 hours; after centrifugation and washing, the mixture is dried to obtain the nano-hybrid; wherein the halloysite nanotubes, fluorinated graphene, organomontmorillonite, organic solvent, and N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt are present. The mass ratio of sodium diaminetriacetate is 0.3:0.5:3:20:0.3; the molar ratio of sodium N-(trimethoxysilylpropyl)ethylenediaminetriacetate and 1-ethyl-3-methylimidazolium iodide is 1:3; the halloysite nanotubes have a diameter of 50-300 nm and a length of 1-10 μm; the fluorinated graphene has a fluorine content of 60%, a sheet diameter of 1-5 μm, and a thickness of 5-10 nm, and is provided by Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., item number 106790, part number XF225; the organomontmorillonite is Fenghong DK2 polymer-grade organomontmorillonite.

[0049] The synergistic component is composed of nano-hydroxyapatite and nano-zirconium dioxide in a mass ratio of 3:1; the average particle size of the synergistic component is 80 nm; the pigment and filler are composed of rutile titanium dioxide, precipitated barium sulfate, and mica powder in a mass ratio of 2:1:1.2; the average particle size of the pigment and filler is 1500 mesh; the coupling agent is silane coupling agent KH550; the auxiliary agent is composed of leveling agent, degassing agent, and anti-caking agent in a mass ratio of 2:1:1.2; the leveling agent is BYK-333; the anti-caking agent is fumed silica AEROSIL®200; and the degassing agent is benzoin.

[0050] A production process for the anti-corrosion powder coating based on nano-hybrids includes the following steps: mixing the components evenly to obtain a mixture; transferring the mixture to a twin-screw extruder for extrusion granulation, followed by crushing and sieving to obtain the anti-corrosion powder coating based on nano-hybrids; the extrusion temperature of the twin-screw extruder is 140°C; and the sieving is through a 150-mesh sieve.

[0051] Comparative Example 1: An anti-corrosion powder coating based on nano-hybrids and its production process, which is basically the same as Example 5, except that an equal amount of epoxy resin is used instead of epoxy-based fluorinated polyarylether ketone as E12 solid epoxy resin.

[0052] Comparative Example 2: An anti-corrosion powder coating based on nano-hybrids and its production process, which is basically the same as Example 5, except that an equal amount of NPES-901 solid epoxy resin is replaced with E12 solid epoxy resin.

[0053] Comparative Example 3: An anti-corrosion powder coating based on nano-hybrids and its production process, which is basically the same as Example 5, except that an equal amount of E12 solid epoxy resin is used instead of NPES-901 solid epoxy resin.

[0054] Comparative Example 4: An anti-corrosion powder coating based on nano-hybrids and its production process, which is basically the same as Example 5, except that an equal amount of 9,9-bis(4-aminophenyl)fluorene is used instead of isophthalic acid dihydrazide.

[0055] Comparative Example 5: An anti-corrosion powder coating based on nano-hybrids and its production process, which is basically the same as Example 5, except that an equal amount of isophthalic acid dihydrazide is used instead of 9,9-bis(4-aminophenyl)fluorene.

[0056] Comparative Example 6: An anti-corrosion powder coating based on nano-hybrids and its production process, which is basically the same as Example 5, except that an equal amount of halloysite nanotubes are used instead of fluorinated graphene.

[0057] Comparative Example 7: An anti-corrosion powder coating based on nano-hybrids and its production process, which is basically the same as Example 5, except that an equal amount of fluorinated graphene is used instead of halloysite nanotubes.

[0058] Comparative Example 8: An anti-corrosion powder coating based on nano-hybrids and its production process, which is basically the same as that of Example 5, except that the step of adding 1-ethyl-3-methylimidazolium iodide is not included.

[0059] The anti-corrosion powder coatings based on nano-hybrids from Examples 5 and Comparative Examples 1-8 were subjected to relevant performance tests. The test results are shown in Table 1. The test methods are as follows: Test Sample Preparation: Steel plates conforming to the requirements of GB / T 9271-2008 Standard Test Panels for Paints and Varnishes were selected as standard test panels. First, the surface of the steel plate was sanded. After sanding, the steel plate was ultrasonically cleaned in acetone and anhydrous ethanol sequentially, each cleaning time being 15 minutes. After cleaning, the steel plate was placed in a drying oven and dried at 80°C for 30 minutes for later use. Under the same spraying pressure of 0.4 MPa, the coatings prepared in Example 5 and Comparative Examples 1-8 were sprayed onto the standard test panels preheated in an oven at 180°C for 15 minutes using high-voltage electrostatic spraying. During spraying, the distance between the spray gun and the test panel was maintained at 20 cm, and the spray gun was moved at a uniform speed to ensure uniform coating coverage. The coating thickness was approximately 100 μm. After spraying, the coated test panels were quickly placed in a curing oven at 160°C for 20 minutes. After curing, the test plate was removed and allowed to cool naturally to room temperature to obtain the test sample.

[0060] The test samples were tested using the following test methods: (1) Adhesion test: Refer to GB / T 9286-1998 standard, adopt the cross-cut method, use a sharp blade to cut 100 small squares on the metal test piece coated with powder coating, then stick it with special tape and quickly tear it off, observe the coating peeling in the squares to evaluate the adhesion. The adhesion level is divided into 0-5, with 0 being the best and 5 being the worst.

[0061] (2) Salt spray resistance test: The test was conducted in accordance with GB / T 1771-2007. The concentration of sodium chloride solution was 55 g / L, and the test period was 1500 h. The test was conducted to observe whether the paint film of the sample showed blistering or peeling.

[0062] (3) Impact resistance test: The test was conducted in accordance with GB / T 1732-2020, and a 4x magnifying glass was used to observe whether there were cracks, wrinkles and peeling. The maximum height (cm) of the hammer when no cracks, wrinkles and peeling were observed in three tests is recorded in Table 1. The greater the maximum height of the hammer, the better the impact resistance of the paint film.

[0063] (4) Chemical resistance test: Refer to Method A of GB / T 9274-1988, immerse the coated samples in 5% sulfuric acid and 5% sodium hydroxide solution respectively, and record the appearance changes of the coating after 24 hours of immersion.

[0064] As shown in Table 1, the anti-corrosion powder coating based on nano-hybrids described in Example 5, through the use of an epoxy resin system composed of E12 solid epoxy resin, NPES-901 solid epoxy resin and epoxy-based fluorinated polyarylether ketone in a specific ratio, a curing agent system composed of dicyandiamide, 9,9-bis(4-ylphenyl)fluorene and isophthalic acid dihydrazide in a specific ratio, and a nano-hybrid composed of halloysite nanotubes, fluorinated graphene and organomontmorillonite in a specific ratio and modified with 1-ethyl-3-methylimidazolium iodide, demonstrates the synergistic effect and complementary advantages of each component, resulting in a coating with excellent adhesion (0. The coating exhibits excellent performance in terms of adhesion, impact resistance (80cm), salt spray resistance (the coating film remains intact and bubble-free after 1500h test), and acid and alkali resistance (no visible changes after immersion in 5% sulfuric acid and 5% sodium hydroxide solutions for 24h). In contrast, comparative examples 1-8, due to the absence of the aforementioned key components or modification steps, all showed varying degrees of decreased adhesion, reduced impact resistance, worsened salt spray resistance, and decreased acid and alkali resistance. This fully verifies the rationality of the formulation composition and preparation process of this application, as well as the synergistic effect among the key components, which can effectively improve the comprehensive anti-corrosion and mechanical properties of the anti-corrosion powder coating.

[0065] Table 1 Performance test results of anti-corrosion powder coatings based on nano-hybrids

[0066] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A corrosion-resistant powder coating based on nano-hybrids, characterized in that, The product comprises the following components by weight: 40-50 parts epoxy resin, 5-8 parts curing agent, 5-10 parts nano-hybrids, 2-5 parts synergistic components, 10-15 parts pigments and fillers, 1-3 parts coupling agent, and 2-5 parts additives; wherein the epoxy resin is a compound of E12 solid epoxy resin, NPES-901 solid epoxy resin, and epoxy-based fluorinated polyarylether ketone in a mass ratio of 1:(1-2):(0.1-0.3).

2. The anti-corrosion powder coating based on nano-hybrids according to claim 1, characterized in that, The curing agent is a compound of dicyandiamide, 9,9-bis(4-aminophenyl)fluorene, and isophthalic acid dihydrazide in a mass ratio of (3-5):1:(0.8-1.2).

3. The anti-corrosion powder coating based on nano-hybrids according to claim 1, characterized in that, The preparation method of the nano-hybrid includes the following steps: halloysite nanotubes, fluorinated graphene, and organomontmorillonite are uniformly dispersed in an organic solvent, then N-(trimethoxysilylpropyl)ethylenediaminetriacetic acid sodium salt is added to the solvent, and the mixture is stirred at 60-80℃ for 3-5 hours. After removing the solvent by rotary evaporation, the mixture is added to an aqueous solution of 1-ethyl-3-methylimidazolium iodide with a mass percentage concentration of 10-20%, and the mixture is stirred at 50-70℃ for 8-10 hours. After centrifugation, washing, and drying, the nano-hybrid is obtained.

4. The anti-corrosion powder coating based on nano-hybrids according to claim 3, characterized in that, The mass ratio of halloysite nanotubes, fluorinated graphene, organomontmorillonite, organic solvent, and N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt is (0.1-0.3):0.5:(2-3):(15-20):(0.1-0.3).

5. The anti-corrosion powder coating based on nano-hybrids according to claim 3, characterized in that, The molar ratio of N-(trimethoxysilylpropyl)ethylenediamine triacetate sodium salt to 1-ethyl-3-methylimidazolium iodide is 1:

3.

6. The anti-corrosion powder coating based on nano-hybrids according to claim 3, characterized in that, The halloysite nanotubes have a diameter of 50-300 nm and a length of 1-10 μm; the fluorinated graphene has a fluorine content of 60%, a sheet diameter of 1-5 μm, and a thickness of 5-10 nm; the organomontmorillonite is Fenghong DK2 polymer-grade organomontmorillonite.

7. The anti-corrosion powder coating based on nano-hybrids according to claim 1, characterized in that, The synergistic component is composed of nano-hydroxyapatite and nano-zirconia in a mass ratio of (1-3):1; the average particle size of the synergistic component is 20-80 nm; the pigment and filler are composed of rutile titanium dioxide, precipitated barium sulfate, and mica powder in a mass ratio of (1-2):1:(0.8-1.2); the average particle size of the pigment and filler is 500-1500 mesh.

8. The anti-corrosion powder coating based on nano-hybrids according to claim 1, characterized in that, The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the additives are leveling agents, degassing agents, and anti-caking agents compounded in a mass ratio of (1-2):1:(0.8-1.2); the leveling agent is BYK-333; the anti-caking agent is fumed silica AEROSIL®200; and the degassing agent is benzoin.

9. A production process for an anti-corrosion powder coating based on nano-hybrids according to any one of claims 1-8, characterized in that, The process includes the following steps: mixing the components evenly to obtain a mixture; transferring the mixture to a twin-screw extruder for extrusion granulation, followed by crushing and sieving to obtain an anti-corrosion powder coating based on nano-hybrids.

10. The production process of the anti-corrosion powder coating based on nano-hybrids according to claim 9, characterized in that, The extrusion temperature of the twin-screw extruder is 110℃~140℃; the sieving is performed through a 100-150 mesh sieve.

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