A graphene-reinforced epoxy-modified silicone resin heavy-duty powder coating

Abstract

The present application relates to heavy-duty anticorrosive coating technical field, specifically to a kind of graphene reinforced epoxy modified silicone resin heavy-duty anticorrosive powder coating, by weight parts, consisting of following components: epoxy group epoxide modified silicone resin 42-58 parts, hydroxylated graphene 0.8-2.5 parts, nano zirconium dioxide coated boron nitride 6-11 parts, lanthanum isooctanoate-titanate complex coupling agent 2.5-5.5 parts, bis (3-triethoxysilane propyl) disulfide 1.5-3.5 parts, cage silsesquioxane 4-7 parts, curing agent 5-8 parts, leveling agent 0.8-1.8 parts, defoaming agent 0.4-0.9 parts, polyether ether ketone micro powder 2.5-4.5 parts, fluorine-containing phosphate 1.2-2.8 parts.The present application is modified by chemical bridging resin, and modified graphene and nano-coated powder are used to build synergistic reinforcement system, and the interface is optimized by composite coupling agent.Adhesion, corrosion resistance and mechanical properties of the coating are excellent, processing fluidity is good, aging resistance and thermal stability are strong, traditional product performance short board is solved, and industrialization demand is adapted.

Description

Technical Field

[0001] This invention relates to the field of heavy-duty anti-corrosion coatings, specifically a graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating. Background Technology

[0002] Heavy-duty anti-corrosion powder coatings are widely used in harsh corrosive environments such as petrochemicals, marine engineering, and bridge construction due to their solvent-free evaporation and excellent coating performance. Currently, mainstream products use epoxy, polyester, and silicone resins as base materials. However, single resin systems have significant shortcomings: epoxy resins have strong adhesion but insufficient weather resistance and high-temperature resistance, and are prone to chalking after long-term exposure; silicone resins have outstanding high and low temperature resistance and weather resistance, but suffer from poor adhesion and slow curing speed, making it difficult to achieve a balance between anti-corrosion, adhesion, and mechanical properties.

[0003] To optimize performance, the industry often uses epoxy-modified silicone resins. However, traditional modification processes are mostly achieved through simple physical blending or direct copolymerization, resulting in poor resin compatibility and weak interfacial bonding, which makes the coating prone to microcracks. At the same time, existing reinforcing fillers are mainly conventional powders such as talc and mica powder, which have limited reinforcing effects. Moreover, the uneven dispersion of fillers and resin matrix further reduces the density of the coating and makes it unable to block the penetration of corrosive media such as chloride ions and water molecules.

[0004] Graphene has become a research hotspot due to its excellent mechanical and barrier properties. However, unmodified graphene has a highly inert surface, poor compatibility with resins, and is prone to agglomeration, forming defects. While nanoparticles can improve coating performance, individual nanoparticles are prone to agglomeration and lack synergistic design with graphene. Coupling agents mostly use single silane or titanate types, which are difficult to improve the interfacial bonding between inorganic fillers, organic resins, and graphene simultaneously, thus limiting the improvement of coating mechanical strength and corrosion resistance.

[0005] Furthermore, in existing powder coating preparation processes, the melt extrusion process is prone to premature resin curing due to excessively high local temperatures, and the pulverization stage easily produces uneven particle size distribution, affecting the coating's leveling properties and appearance. In harsh corrosive environments, traditional coatings often exhibit insufficient resistance to salt spray and damp heat, resulting in blistering and peeling within a short period, and a service life far shorter than expected. Therefore, developing a heavy-duty anti-corrosion powder coating that combines strong adhesion, high density, excellent corrosion resistance, and mechanical properties, while addressing technical pain points such as insufficient resin modification, poor filler dispersion, and weak interfacial bonding, has become a key issue that the industry urgently needs to overcome. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the shortcomings of existing technologies, this invention provides a graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating.

[0008] (II) Technical Solution

[0009] A graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating, by weight, comprises the following components: 42-58 parts of epoxy-modified silicone resin, 0.8-2.5 parts of hydroxylated graphene, 6-11 parts of nano-zirconia-coated boron nitride, 2.5-5.5 parts of lanthanum isooctanoate-titanium ester composite coupling agent, 1.5-3.5 parts of bis(3-triethoxysilylpropyl)disulfide, 4-7 parts of cage-like silsesquioxane, 5-8 parts of curing agent, 0.8-1.8 parts of leveling agent, 0.4-0.9 parts of defoamer, 2.5-4.5 parts of polyetheretherketone micropowder, and 1.2-2.8 parts of fluorophosphate; wherein the epoxy-modified silicone resin is produced by reacting epoxy resin and silicone resin via γ-(2,3)... The product is prepared by bridging reaction of propyltrimethoxysilane (-epoxypropoxy)propyltrimethoxysilane, with the reaction formula R-Si(OR')3+HO-R"-Ep→R-Si(OR')2-OR"-Ep+R'OH, where Ep is an epoxy group, R is methyl or ethyl, R' is methyl or ethyl, and R" is propylene or butylene. The epoxy resin used is E-51 or E-44, and the silicone resin is methylphenyl silicone resin, with a mass ratio of 3.5:1-4.5:1. The bridging reaction temperature is controlled at 80-90℃, the reaction time is 3-4 hours, the pH of the reaction system is maintained at 6.5-7.5, the epoxy value of the product is 0.25-0.35 eq / 100g, and the number average molecular weight is 8000-12000 g / mol.

[0010] Furthermore, the present invention also includes 0.2-0.9 parts of nano-graphene oxide quantum dots with a particle size of 4-9 nm, the surface of which simultaneously contains carboxyl and epoxy functional groups, with a carboxyl content of 0.8-1.5 mmol / g and an epoxy content of 0.5-1.2 mmol / g; the nano-graphene oxide quantum dots are prepared by nitric acid oxidation cutting of graphene nanosheets at an oxidation temperature of 120-140℃ for 6-8 hours, followed by dialysis purification and drying in a vacuum drying oven at 60-70℃ for 12-16 hours, resulting in a powder specific surface area of ​​300-500 m². 2 / g, dispersibility ≥90%.

[0011] Furthermore, the present invention also includes 2.5-4.5 parts of modified montmorillonite, wherein the modified montmorillonite is subjected to a composite intercalation treatment with hexadecyltrimethylammonium bromide and γ-aminopropyltriethoxysilane, wherein the amount of hexadecyltrimethylammonium bromide is 15-25% of the mass of montmorillonite, and the amount of γ-aminopropyltriethoxysilane is 5-10% of the mass of montmorillonite; the treatment process is as follows: montmorillonite is added to deionized water and stirred and dispersed at 60-70°C for 1-2 hours, then hexadecyltrimethylammonium bromide and γ-aminopropyltriethoxysilane are added sequentially, and the reaction is carried out at 80-90°C for 3-4 hours. After filtration, it is washed with deionized water until no bromide ions are detected, dried at 80-90°C for 8-10 hours, pulverized and passed through a 400-mesh sieve. The interlayer spacing after treatment is 2.5-4.5 nm, and the thermal weight loss temperature is ≥300°C.

[0012] Furthermore, the hydroxylated graphene of the present invention is prepared by the Hummers method and then reduced by hydroxylamine hydrochloride. In the Hummers method, the mass ratio of graphite to potassium permanganate is 1:3-1:5, the reaction temperature is 30-40℃, and the reaction time is 2-3 hours. During the reduction treatment, the amount of hydroxylamine hydrochloride is 30-50% of the mass of graphene oxide, the reduction temperature is 60-70℃, and the reduction time is 2-3 hours. After reduction, it is washed with deionized water until neutral, and then freeze-dried to obtain hydroxylated graphene. The obtained hydroxylated graphene has a hydroxyl content of 1.5-2.2 mmol / g, a sheet diameter of 1.2-2.8 μm, a thickness of 0.7-0.9 nm, an electrical conductivity of 500-800 S / m, and a carbon-oxygen ratio of 8-12:1.

[0013] Furthermore, the nano-zirconia-coated boron nitride of this invention is prepared by a sol-gel method, with zirconium oxychloride as the zirconium dioxide precursor and a mixture of ethanol and water in a volume ratio of 3:1-4:1 as the solvent. The boron nitride powder has a particle size of 30-50 nm. The preparation process involves dispersing boron nitride in the solvent, ultrasonically treating it for 30-40 minutes, adding zirconium oxychloride solution and ammonia, adjusting the pH to 9-10, stirring and reacting at 50-60°C for 2-3 hours, filtering and washing until no chloride ions are present, drying at 100-110°C for 6-8 hours, and calcining at 500-600°C for 2-3 hours. The coating amount is 12-18 wt%, the final product has a particle size of 60-90 nm, a thermal conductivity of 22-28 W / (m·K), a water contact angle of 85-95°, and a Mohs hardness of 5-6.

[0014] Furthermore, in the lanthanum isooctanoate-titanium ester composite coupling agent of the present invention, the mass ratio of lanthanum isooctanoate to titanate is 1:3.5-1:4.5, and the titanate is isopropyltris(dioctylpyrophosphoryloxy) titanate; the composite coupling agent is prepared by stirring and reacting lanthanum isooctanoate and titanate at 60-70°C for 1-2 hours, with nitrogen gas purging during the reaction, stirring speed of 300-400 r / min, and cooling to room temperature after the reaction is completed. The product viscosity is 200-300 mPa·s (25°C), the content of effective ingredients is ≥98%, and the pH value is 6-7.

[0015] Furthermore, the cage-like silsesquioxane described in this invention is an octaaminophenyl cage-like silsesquioxane, prepared by hydrolysis and condensation of phenyltrichlorosilane in a toluene and ammonia mixture. The volume ratio of toluene to ammonia is 5:1-6:1, the concentration of phenyltrichlorosilane is 0.1-0.2 mol / L, the reaction temperature is 0-5℃, and the reaction time is 4-6 hours. After the reaction, the mixture is filtered, washed successively with toluene and ethanol, and dried under vacuum at 60-70℃ for 8-10 hours. The product has a particle size of 60-90 nm, an amino content of 3.8-4.2 mmol / g, a thermal decomposition temperature ≥450℃, and a carbon residue rate ≥50% at 800℃ under a nitrogen atmosphere.

[0016] Furthermore, this invention also proposes a method for preparing graphene-reinforced epoxy-modified organosilicon resin heavy-duty anti-corrosion powder coating, comprising the following steps: S1. Graphene modification: Hydroxylated graphene is added to deionized water at a solid-liquid ratio of 1:50-1:80, ultrasonically dispersed for 45-75 minutes, and bis(3-triethoxysilylpropyl) disulfide is added at an amount of 10-20% of the graphene mass. The mixture is stirred at 62-68°C for 3.5-4.5 hours at a stirring speed of 400-500 r / min. After the reaction is completed, it is freeze-dried to obtain silane-modified graphene; S2. Premixing: Epoxy-modified epoxy organosilicon resin, silane-modified graphene, nano-zirconia-coated boron nitride, cage-like silsesquioxane, and polyetheretherketone micropowder are added to a high-speed mixer according to the specified ratio, and stirred in a planetary mixer at 2200 rpm. - Stir at 2800 r / min for 16-19 minutes, controlling the material temperature to not exceed 40℃ during stirring; S3. Melting reaction: Add lanthanum isooctanoate-titanium ester composite coupling agent, fluorinated phosphate, curing agent, leveling agent, and defoamer to the mixture, mix evenly, and then feed it into a twin-screw extruder. Control the temperature of zone 1 to 90-100℃, zone 2 to 115-125℃, zone 3 to 115-125℃, and zone 4 to 100-110℃, with a screw speed of 380-420 r / min. Maintain a nitrogen atmosphere during extrusion; S4. Post-treatment: Cool the extrudate to room temperature using cooling rollers, crush it into particles with a diameter of 5-10 mm, and then pulverize it in an ultra-fine pulverizer. After pulverization, pass it through a 220-280 mesh sieve. After sieving, vacuum dry the material at 40-50℃ for 2-3 hours to obtain a heavy-duty anti-corrosion powder coating.

[0017] Furthermore, in S1 of this invention, the ultrasonic power is 450-550W, the ultrasonic frequency is 25-30kHz; the freeze-drying temperature is -45 to -48℃, the vacuum degree is 5-8Pa, the time is 15-21 hours, and the moisture content of the dried material is ≤0.1%; the modified graphene has a dispersion stability in xylene ≥72 hours and a sedimentation rate ≤5%.

[0018] Furthermore, in S3 of this invention, the nitrogen flow rate is 0.6-0.9 L / min, the oxygen content is controlled below 0.5%, and the material residence time in the extruder is 30-60 seconds; in S4, the ultrafine pulverizer uses liquid nitrogen cryogenic pulverization, the pulverization temperature is -85 to -95℃, the pulverization pressure is 0.7-0.8 MPa, the particle size distribution D50 of the pulverized material is 30-50 μm, the particle size distribution span is ≤1.5, and the powder loose density is 0.4-0.6 g / cm³. 3 Flowability ≤30s / 100g.

[0019] (III) Beneficial Technical Effects

[0020] Compared with existing technologies, the beneficial effects of this invention are:

[0021] Regarding the performance of the resin matrix, an innovative approach is adopted to prepare epoxy-modified silicone resin by bridging with γ-(2,3-epoxypropoxy)propyltrimethoxysilane. This approach strengthens the interfacial bonding between the epoxy resin and the silicone resin through chemical bonding, retaining the strong adhesion of the epoxy resin while also possessing the high and low temperature resistance and weather resistance of the silicone resin. This solves the problems of poor compatibility and performance imbalance of traditional modified resins, providing a stable and reliable matrix support for the coating.

[0022] The filler synergistic reinforcement effect is significant. After modification with sulfide silane, the compatibility of hydroxylated graphene with the resin matrix is ​​greatly improved, and the sheet-like structure can form a dense barrier network. Nano-zirconia coated boron nitride has both thermal conductivity and wear resistance properties, forming a synergistic reinforcement system with graphene to effectively block the penetration of corrosive media. The addition of cage-like silsesquioxane further improves the crosslinking density and thermal stability of the coating. The composite use of modified montmorillonite and nano-graphene oxide quantum dots fills the gaps caused by graphene agglomeration, significantly improving the density and mechanical strength of the coating.

[0023] Interfacial bonding and process compatibility optimization: Lanthanum isooctanoate-titanium ester composite coupling agent can simultaneously improve the interfacial bonding between inorganic fillers, graphene, and organic resins, enhance interfacial forces, and reduce interfacial defects. Nitrogen-protected melt extrusion and liquid nitrogen cryogenic pulverization processes during preparation prevent premature resin curing, ensure uniform powder particle size distribution, and improve coating leveling and appearance quality.

[0024] Overall, this patented coating possesses excellent adhesion, mechanical strength, resistance to high and low temperatures, and corrosion resistance, effectively resisting corrosive media in harsh environments and extending the coating's service life. Furthermore, its scientifically designed process is well-suited to the needs of industrial production, providing a superior coating solution for high-end heavy-duty anti-corrosion applications, demonstrating significant practical value and market potential. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the preparation process of the graphene-reinforced epoxy-modified organosilicon resin heavy-duty anti-corrosion powder coating proposed in this invention.

[0026] Figure 2 This is a bar chart showing the corrosion resistance of the coating;

[0027] Appendix Figure 3 Line graph of coating mechanical properties;

[0028] Appendix Figure 4 : Bar chart showing the combination of coating processing and durability performance. Detailed Implementation

[0029] according to Figures 1 to 4 The specific embodiments of the present invention are as follows:

[0030] A graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating, by weight, comprises the following components: 42-58 parts of epoxy-modified silicone resin, 0.8-2.5 parts of hydroxylated graphene, 6-11 parts of nano-zirconia-coated boron nitride, 2.5-5.5 parts of lanthanum isooctanoate-titanium ester composite coupling agent, 1.5-3.5 parts of bis(3-triethoxysilylpropyl)disulfide, 4-7 parts of cage-like silsesquioxane, 5-8 parts of curing agent, 0.8-1.8 parts of leveling agent, 0.4-0.9 parts of defoamer, 2.5-4.5 parts of polyetheretherketone micropowder, and 1.2-2.8 parts of fluorophosphate; wherein the epoxy-modified silicone resin is produced by reacting epoxy resin and silicone resin via γ-(2,3)... The product is prepared by bridging reaction of propyltrimethoxysilane (-epoxypropoxy)propyltrimethoxysilane, with the reaction formula R-Si(OR')3+HO-R"-Ep→R-Si(OR')2-OR"-Ep+R'OH, where Ep is an epoxy group, R is methyl or ethyl, R' is methyl or ethyl, and R" is propylene or butylene. The epoxy resin used is E-51 or E-44, and the silicone resin is methylphenyl silicone resin, with a mass ratio of 3.5:1-4.5:1. The bridging reaction temperature is controlled at 80-90℃, the reaction time is 3-4 hours, the pH of the reaction system is maintained at 6.5-7.5, the epoxy value of the product is 0.25-0.35 eq / 100g, and the number average molecular weight is 8000-12000 g / mol.

[0031] This invention also includes 0.2-0.9 parts of nano-graphene oxide quantum dots with a particle size of 4-9 nm, the surface of which simultaneously contains carboxyl and epoxy functional groups, with a carboxyl content of 0.8-1.5 mmol / g and an epoxy content of 0.5-1.2 mmol / g; the nano-graphene oxide quantum dots are prepared by nitric acid oxidation cutting of graphene nanosheets at an oxidation temperature of 120-140℃ for 6-8 hours, followed by dialysis purification and drying in a vacuum drying oven at 60-70℃ for 12-16 hours, resulting in a powder with a specific surface area of ​​300-500 m². 2 / g, dispersibility ≥90%.

[0032] The present invention also includes 2.5-4.5 parts of modified montmorillonite, wherein the modified montmorillonite is subjected to a composite intercalation treatment with hexadecyltrimethylammonium bromide and γ-aminopropyltriethoxysilane. The amount of hexadecyltrimethylammonium bromide is 15-25% of the mass of montmorillonite, and the amount of γ-aminopropyltriethoxysilane is 5-10% of the mass of montmorillonite. The treatment process is as follows: montmorillonite is added to deionized water and stirred and dispersed at 60-70°C for 1-2 hours. Hexadecyltrimethylammonium bromide and γ-aminopropyltriethoxysilane are added sequentially and reacted at 80-90°C for 3-4 hours. After filtration, it is washed with deionized water until no bromide ions are detected. It is dried at 80-90°C for 8-10 hours, pulverized, and passed through a 400-mesh sieve. The interlayer spacing after treatment is 2.5-4.5 nm, and the thermal weight loss temperature is ≥300°C.

[0033] The hydroxylated graphene of this invention is prepared by the Hummers method and then reduced by hydroxylamine hydrochloride. In the Hummers method, the mass ratio of graphite to potassium permanganate is 1:3-1:5, the reaction temperature is 30-40℃, and the reaction time is 2-3 hours. During the reduction treatment, the amount of hydroxylamine hydrochloride is 30-50% of the mass of graphene oxide, the reduction temperature is 60-70℃, and the reduction time is 2-3 hours. After reduction, it is washed with deionized water until neutral, and then freeze-dried to obtain hydroxylated graphene. The obtained hydroxylated graphene has a hydroxyl content of 1.5-2.2 mmol / g, a sheet diameter of 1.2-2.8 μm, a thickness of 0.7-0.9 nm, an electrical conductivity of 500-800 S / m, and a carbon-to-oxygen ratio of 8-12:1.

[0034] The present invention describes the preparation of nano-zirconia-coated boron nitride via a sol-gel method. The zirconia precursor is zirconium oxychloride, and the solvent is a mixture of ethanol and water in a volume ratio of 3:1-4:1. The boron nitride powder has a particle size of 30-50 nm. The preparation process involves dispersing boron nitride in the solvent, ultrasonically treating it for 30-40 minutes, adding zirconium oxychloride solution and ammonia, adjusting the pH to 9-10, stirring the reaction at 50-60°C for 2-3 hours, filtering, washing until no chloride ions are present, drying at 100-110°C for 6-8 hours, and calcining at 500-600°C for 2-3 hours. The coating amount is 12-18 wt%, the final product has a particle size of 60-90 nm, a thermal conductivity of 22-28 W / (m·K), a water contact angle of 85-95°, and a Mohs hardness of 5-6.

[0035] In the lanthanum isooctanoate-titanium ester composite coupling agent of the present invention, the mass ratio of lanthanum isooctanoate to titanate is 1:3.5-1:4.5, and the titanate is isopropyltris(dioctylpyrophosphoryloxy) titanate. The composite coupling agent is prepared by stirring lanthanum isooctanoate and titanate at 60-70℃ for 1-2 hours, with nitrogen gas purging during the reaction, stirring speed of 300-400 r / min, and cooling to room temperature after the reaction. The product viscosity is 200-300 mPa·s (25℃), the content of effective ingredients is ≥98%, and the pH value is 6-7.

[0036] The cage-like silsesquioxane described in this invention is an octaaminophenyl cage-like silsesquioxane, prepared by hydrolysis and condensation of phenyltrichlorosilane in a toluene and ammonia mixture. The volume ratio of toluene to ammonia is 5:1-6:1, the concentration of phenyltrichlorosilane is 0.1-0.2 mol / L, the reaction temperature is 0-5℃, and the reaction time is 4-6 hours. After the reaction, the mixture is filtered, washed successively with toluene and ethanol, and dried under vacuum at 60-70℃ for 8-10 hours. The product has a particle size of 60-90 nm, an amino content of 3.8-4.2 mmol / g, a thermal decomposition temperature ≥450℃, and a carbon residue rate ≥50% at 800℃ under a nitrogen atmosphere.

[0037] This invention also proposes a method for preparing graphene-reinforced epoxy-modified organosilicon resin heavy-duty anti-corrosion powder coating, comprising the following steps: S1. Graphene modification: Hydroxylated graphene is added to deionized water at a solid-liquid ratio of 1:50-1:80, ultrasonically dispersed for 45-75 minutes, and bis(3-triethoxysilylpropyl) disulfide is added at an amount of 10-20% of the graphene mass. The mixture is stirred at 62-68℃ for 3.5-4.5 hours at a stirring speed of 400-500 r / min. After the reaction is completed, the mixture is freeze-dried to obtain silane-modified graphene; S2. Premixing: Epoxy-modified epoxy organosilicon resin, silane-modified graphene, nano-zirconia-coated boron nitride, cage-like silsesquioxane, and polyetheretherketone micropowder are added to a high-speed mixer according to the specified ratio, and stirred in a planetary mixer at 2200-200 rpm. Stir at 800 rpm for 16-19 minutes, controlling the material temperature to not exceed 40℃ during stirring; S3. Melting reaction: Add lanthanum isooctanoate-titanium ester composite coupling agent, fluorinated phosphate, curing agent, leveling agent, and defoamer to the mixture, mix evenly, and then feed it into a twin-screw extruder. Control the temperature of zone 1 to 90-100℃, zone 2 to 115-125℃, zone 3 to 115-125℃, and zone 4 to 100-110℃, with a screw speed of 380-420 rpm. Maintain a nitrogen atmosphere during extrusion; S4. Post-treatment: Cool the extrudate to room temperature using cooling rollers, crush it into particles with a diameter of 5-10 mm, and then pulverize it in an ultra-fine pulverizer. After pulverization, pass it through a 220-280 mesh sieve. After sieving, vacuum dry the material at 40-50℃ for 2-3 hours to obtain a heavy-duty anti-corrosion powder coating.

[0038] In this invention, S1 has an ultrasonic power of 450-550W and an ultrasonic frequency of 25-30kHz; a freeze-drying temperature of -45 to -48℃, a vacuum degree of 5-8Pa, a time of 15-21 hours, and a moisture content of the dried material of ≤0.1%; the modified graphene has a dispersion stability of ≥72 hours in xylene and a sedimentation rate of ≤5%.

[0039] In this invention, in S3, the nitrogen flow rate is 0.6-0.9 L / min, the oxygen content is controlled below 0.5%, and the material residence time in the extruder is 30-60 seconds. In S4, the ultrafine pulverizer uses liquid nitrogen cryogenic pulverization, with a pulverization temperature of -85 to -95℃ and a pulverization pressure of 0.7-0.8 MPa. The particle size distribution D50 of the pulverized material is 30-50 μm, the particle size distribution span is ≤1.5, and the loose powder density is 0.4-0.6 g / cm³. 3 Flowability ≤30s / 100g.

[0040] Example 1

[0041] Raw material preparation: Prepare the following raw materials by weight: 45 parts of epoxy-modified silicone resin, 1.2 parts of hydroxylated graphene, 8 parts of nano-zirconia-coated boron nitride, 3 parts of lanthanum isooctanoate-titanium ester composite coupling agent, 2 parts of bis(3-triethoxysilylpropyl) disulfide, 5 parts of cage-like silsesquioxane, 6 parts of curing agent, 1 part of leveling agent, 0.5 parts of defoamer, 3 parts of polyether ether ketone micro powder, 1.8 parts of fluorinated phosphate ester, 0.4 parts of nano-graphene oxide quantum dots, and 3 parts of modified montmorillonite.

[0042] Resin Preparation: E-51 epoxy resin and methylphenyl silicone resin were mixed at a mass ratio of 4:1, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added at 5% of the total resin mass. The mixture was stirred at 85°C for 3.5 hours, and the pH was adjusted to 7 with acetic acid during the reaction to obtain an epoxy-modified silicone resin with an epoxy value of 0.3 eq / 100g and a number-average molecular weight of 10000 g / mol.

[0043] Preparation of hydroxylated graphene by filler pretreatment: Using the Hummers method, graphite and potassium permanganate reacted at a mass ratio of 1:4 and stirred at 35°C for 2.5 hours. Hydroxylamine hydrochloride (40% by weight of graphene oxide) was added, and the mixture was reduced at 65°C for 2.5 hours. After washing to neutrality, it was freeze-dried to obtain hydroxylated graphene with a hydroxyl content of 1.8 mmol / g. The sheet had a diameter of 1.8 μm, a thickness of 0.8 nm, an electrical conductivity of 650 S / m, and a carbon-to-oxygen ratio of 10:1. Preparation of boron nitride coated with nano-zirconia: 30 nm of boron nitride was dispersed in an ethanol-water mixture (3.5:1 volume ratio) and sonicated for 35 minutes. Zirconium oxychloride solution and ammonia were added to adjust the pH to 9.5, and the mixture was stirred at 55°C for 2.5 hours, dried at 105°C for 7 hours, and calcined at 550°C for 2.5 hours to obtain a composite powder with a coating weight of 15 wt%. The powder has a particle size of 75 nm, a thermal conductivity of 25 W / (m·K), a water contact angle of 90°, and a Mohs hardness of 5.5. Modified montmorillonite preparation: Montmorillonite was added to deionized water and dispersed by stirring at 65°C for 1.5 hours. Then, 20% (by weight of montmorillonite) of hexadecyltrimethylammonium bromide and 8% (by weight of γ-aminopropyltriethoxysilane) were added sequentially, and the reaction was carried out at 85°C for 3.5 hours. After filtration, the mixture was washed with deionized water until no bromide ions were detected, dried at 85°C for 9 hours, pulverized, and passed through a 400-mesh sieve. The interlayer spacing after treatment was 3.5 nm, and the thermogravimetric temperature was 320°C. Preparation of nano-graphene oxide quantum dots: Graphene nanosheets were cleaved by nitric acid oxidation at 130°C for 7 hours. After dialysis purification, the nano-dots were dried in a vacuum drying oven at 65°C for 14 hours to obtain quantum dots with a particle size of 6 nm. The carboxyl content was 1.2 mmol / g, the epoxy content was 0.8 mmol / g, and the specific surface area was 400 m². 2 / g, dispersibility 92%.

[0044] Preparation of Lanthanum Isooctanoate-Titanium Ester Composite Coupling Agent: Lanthanum isooctanoate and isopropyltris(dioctylpyrophosphate)titanate were mixed at a mass ratio of 1:4 and stirred at 400 r / min for 1.5 hours under nitrogen protection at 65°C to obtain a product with a viscosity of 250 mPa·s. The active ingredient content of this product was 98.5%, and the pH value was 6.5. Cage-like Silsesquioxane: Phenyltrichlorosilane was dissolved in a toluene-ammonia water mixture (5.5:1 volume ratio), reacted at 0-5°C for 5 hours, washed, and then vacuum dried at 65°C for 9 hours to obtain an octaaminophenyl cage-like silsesquioxane with an amino content of 4 mmol / g. The particle size of this product was 75 nm, the thermal decomposition temperature was 460°C, and the char residue at 800°C under a nitrogen atmosphere was 52%.

[0045] Coating Preparation S1. Graphene Modification: Hydroxylated graphene was added to deionized water at a solid-liquid ratio of 1:60, and ultrasonicated at 500W for 60 minutes at a frequency of 28kHz. 15% (by weight of graphene) of bis(3-triethoxysilylpropyl) disulfide was added, and the mixture was stirred at 500r / min for 4 hours at 65℃, followed by vacuum freeze-drying at -46℃ and 6Pa for 18 hours. After drying, the material had a moisture content of 0.08%, a dispersion stability in xylene of 75 hours, and a sedimentation rate of 4%. S2. Premixing: Epoxylated modified silicone resin, sulfide-modified graphene, nano-zirconia-coated boron nitride, cage-like silsesquioxane, polyetheretherketone micropowder, nano-graphene oxide quantum dots, and modified montmorillonite were added to a planetary mixer and stirred at 2500r / min for 17 minutes, controlling the material temperature to not exceed 40℃ during stirring. S3. Melting Reaction: Add lanthanum isooctanoate-titanium ester composite coupling agent, fluorophosphate, curing agent, leveling agent, and defoamer to the mixture, mix thoroughly, and then feed it into a twin-screw extruder. Control the temperatures in zones 1 (95℃), 2 (120℃), 3 (120℃), and 4 (105℃), with a screw speed of 400 r / min, nitrogen flow rate of 0.7 L / min, oxygen content controlled at 0.4%, and material residence time in the extruder of 45 seconds. S4. Post-treatment: Cool the extrudate to room temperature using cooling rollers, crush it into 8mm particles, and feed it into an ultrafine pulverizer for cryogenic pulverization using liquid nitrogen at a pulverization temperature of -90℃ and a pulverization pressure of 0.75 MPa. After pulverization, pass it through a 250-mesh sieve. The sieved material is then vacuum dried at 45℃ for 2.5 hours to obtain a heavy-duty anti-corrosion powder coating. The powder has a particle size distribution (D50) of 40 μm, a particle size distribution span of 1.2, and a loose packing density of 0.5 g / cm³. 3 Flowability 25s / 100g.

[0046] Example 2

[0047] Raw material preparation: Prepare the following raw materials by weight: 50 parts of epoxy-modified silicone resin, 2 parts of hydroxylated graphene, 10 parts of nano-zirconia-coated boron nitride, 4 parts of lanthanum isooctanoate-titanium ester composite coupling agent, 3 parts of bis(3-triethoxysilylpropyl) disulfide, 6 parts of cage-like silsesquioxane, 7 parts of curing agent, 1.5 parts of leveling agent, 0.8 parts of defoamer, 4 parts of polyether ether ketone micro powder, 2.5 parts of fluorinated phosphate ester, 0.7 parts of nano-graphene oxide quantum dots, and 4 parts of modified montmorillonite.

[0048] Resin Preparation: E-44 epoxy resin and methylphenyl silicone resin were mixed at a mass ratio of 4.5:1, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added at 6% of the total resin mass. The mixture was stirred at 88°C for 3.8 hours, and the pH was adjusted to 6.8 with acetic acid during the reaction to obtain an epoxy-modified silicone resin with an epoxy value of 0.32 eq / 100g and a number-average molecular weight of 11000 g / mol.

[0049] Preparation of hydroxylated graphene by filler pretreatment: Using the Hummers method, graphite and potassium permanganate reacted at a mass ratio of 1:4.5, stirred at 38℃ for 2.8 hours. Hydroxylamine hydrochloride (45% by weight of graphene oxide) was added, and reduction was carried out at 68℃ for 2.8 hours. After washing to neutrality, it was freeze-dried to obtain hydroxylated graphene with a hydroxyl content of 2 mmol / g. The sheet had a diameter of 2.2 μm, a thickness of 0.85 nm, an electrical conductivity of 720 S / m, and a carbon-to-oxygen ratio of 11:1. Preparation of boron nitride coated with nano-zirconia: 40 nm boron nitride was dispersed in an ethanol-water mixture (4:1 volume ratio) and sonicated for 38 minutes. Zirconium oxychloride solution and ammonia were added to adjust the pH to 9.8, stirred at 58℃ for 2.8 hours, dried at 108℃ for 7.5 hours, and calcined at 580℃ for 2.8 hours to obtain a composite powder with a coating weight of 17 wt%. The powder has a particle size of 85 nm, a thermal conductivity of 27 W / (m·K), a water contact angle of 92°, and a Mohs hardness of 5.8. Modified montmorillonite preparation: Montmorillonite was added to deionized water and dispersed by stirring at 68°C for 1.8 hours. Then, 23% (by weight of montmorillonite) of hexadecyltrimethylammonium bromide and 9% (by weight of γ-aminopropyltriethoxysilane) were added sequentially, and the reaction was carried out at 88°C for 3.8 hours. After filtration, the mixture was washed with deionized water until no bromide ions were detected, dried at 88°C for 9.5 hours, pulverized, and passed through a 400-mesh sieve. The interlayer spacing after treatment was 4 nm, and the thermogravimetric temperature was 330°C. Preparation of nano-graphene oxide quantum dots: Graphene nanosheets were cleaved by nitric acid oxidation at 135°C for 7.5 hours. After dialysis purification, the nano-dots were dried in a vacuum drying oven at 68°C for 15 hours to obtain quantum dots with a particle size of 7 nm. The carboxyl content was 1.4 mmol / g, the epoxy content was 1 mmol / g, and the specific surface area was 450 m². 2 / g, dispersibility 93%.

[0050] Preparation of Lanthanum Isooctanoate-Titanium Ester Composite Coupling Agent: Lanthanum isooctanoate and isopropyltris(dioctylpyrophosphate)titanate were mixed at a mass ratio of 1:4.5 and stirred at 400 r / min for 1.8 hours under nitrogen protection at 68℃ to obtain a product with a viscosity of 280 mPa·s. The active ingredient content of this product was 99%, and the pH value was 6.8. Cage-like Silsesquioxane: Phenyltrichlorosilane was dissolved in a toluene-ammonia water mixture (5.8:1 volume ratio), reacted at 0-5℃ for 5.5 hours, washed, and then vacuum dried at 68℃ for 9.5 hours to obtain an octaaminophenyl cage-like silsesquioxane with an amino content of 4.1 mmol / g. The particle size of this product was 85 nm, the thermal decomposition temperature was 470℃, and the char residue at 800℃ under a nitrogen atmosphere was 53%.

[0051] Coating Preparation S1. Graphene Modification: Hydroxylated graphene was added to deionized water at a solid-liquid ratio of 1:70, and ultrasonicated at 550W for 70 minutes at an ultrasonic frequency of 29kHz. 18% (by weight of graphene) of bis(3-triethoxysilylpropyl) disulfide was added, and the mixture was stirred at 500r / min for 4.2 hours at 67℃, followed by vacuum freeze-drying at -47℃ and 7Pa for 20 hours. After drying, the material had a moisture content of 0.07%, a dispersion stability in xylene of 78 hours, and a sedimentation rate of 3.5%. S2. Premixing: Epoxylated modified silicone resin, sulfide-modified graphene, nano-zirconia-coated boron nitride, cage-like silsesquioxane, polyetheretherketone micropowder, nano-graphene oxide quantum dots, and modified montmorillonite were added to a planetary mixer and stirred at 2700r / min for 18 minutes, controlling the material temperature to not exceed 40℃ during stirring. S3. Melting Reaction: Add lanthanum isooctanoate-titanium ester composite coupling agent, fluorophosphate, curing agent, leveling agent, and defoamer to the mixture, mix thoroughly, and then feed it into a twin-screw extruder. Control the temperatures in zones 1 (98℃), 2 (123℃), 3 (123℃), and 4 (108℃), screw speed (410 r / min), nitrogen flow rate (0.8 L / min), oxygen content (0.3%), and material residence time in the extruder (50 seconds). S4. Post-treatment: Cool the extrudate to room temperature using cooling rollers, crush it into 9mm particles, and feed it into an ultrafine pulverizer for cryogenic pulverization with liquid nitrogen at a temperature of -92℃ and a pressure of 0.78 MPa. After pulverization, pass the material through a 270-mesh sieve. After sieving, vacuum dry the material at 48℃ for 2.8 hours to obtain a heavy-duty anti-corrosion powder coating. The powder has a particle size distribution (D50) of 45 μm, a particle size distribution span of 1.3, and a loose packing density of 0.55 g / cm³. 3 Flowability 27s / 100g.

[0052] Example 3

[0053] Raw material preparation: Prepare the following raw materials by weight: 43 parts of epoxy-modified silicone resin, 1 part of hydroxylated graphene, 7 parts of nano-zirconia-coated boron nitride, 2.8 parts of lanthanum isooctanoate-titanium ester composite coupling agent, 1.8 parts of bis(3-triethoxysilylpropyl) disulfide, 4.5 parts of cage-like silsesquioxane, 5.5 parts of curing agent, 0.9 parts of leveling agent, 0.6 parts of defoamer, 3.2 parts of polyetheretherketone micro powder, 1.5 parts of fluorinated phosphate ester, 0.3 parts of nano-graphene oxide quantum dots, and 3.2 parts of modified montmorillonite.

[0054] Resin Preparation: E-51 epoxy resin and methylphenyl silicone resin were mixed at a mass ratio of 3.8:1, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added at a mass ratio of 4.5% of the total resin mass. The mixture was stirred at 82°C for 3.2 hours, and the pH was adjusted to 7.2 with acetic acid during the reaction to obtain an epoxy-modified silicone resin with an epoxy value of 0.28 eq / 100g and a number-average molecular weight of 9000 g / mol.

[0055] Preparation of hydroxylated graphene by filler pretreatment: Using the Hummers method, graphite and potassium permanganate reacted at a mass ratio of 1:3.5, stirred at 32℃ for 2.2 hours. Hydroxylamine hydrochloride (35% by weight of graphene oxide) was added, and reduction was carried out at 62℃ for 2.2 hours. After washing to neutrality, it was freeze-dried to obtain hydroxylated graphene with a hydroxyl content of 1.6 mmol / g. The sheet had a diameter of 1.5 μm, a thickness of 0.75 nm, an electrical conductivity of 580 S / m, and a carbon-to-oxygen ratio of 9:1. Preparation of boron nitride coated with nano-zirconia: 35 nm boron nitride was dispersed in an ethanol-water mixture (3.2:1 volume ratio) and sonicated for 32 minutes. Zirconium oxychloride solution and ammonia were added to adjust the pH to 9.2, stirred at 52℃ for 2.2 hours, dried at 102℃ for 6.5 hours, and calcined at 520℃ for 2.2 hours to obtain a composite powder with a coating weight of 13 wt%. The powder has a particle size of 65 nm, a thermal conductivity of 23 W / (m·K), a water contact angle of 88°, and a Mohs hardness of 5.2. Modified montmorillonite preparation: Montmorillonite was added to deionized water and dispersed by stirring at 62°C for 1.2 hours. Then, 18% (by weight of montmorillonite) of hexadecyltrimethylammonium bromide and 7% (by weight of γ-aminopropyltriethoxysilane) were added sequentially, and the reaction was carried out at 82°C for 3.2 hours. After filtration, the mixture was washed with deionized water until no bromide ions were detected, dried at 82°C for 8.5 hours, pulverized, and passed through a 400-mesh sieve. The interlayer spacing after treatment was 3 nm, and the thermogravimetric temperature was 310°C. Preparation of nano-graphene oxide quantum dots: Graphene nanosheets were cleaved by nitric acid oxidation at 125°C for 6.5 hours. After dialysis purification, the nano-dots were dried in a vacuum drying oven at 62°C for 13 hours to obtain quantum dots with a particle size of 5 nm. The carboxyl content was 1 mmol / g, the epoxy content was 0.7 mmol / g, and the specific surface area was 350 m². 2 / g, dispersibility 91%.

[0056] Preparation of Lanthanum Isooctanoate-Titanium Ester Composite Coupling Agent: Lanthanum isooctanoate and isopropyltris(dioctylpyrophosphate)titanate were mixed at a mass ratio of 1:3.5 and stirred at 400 r / min for 1.2 hours under nitrogen protection at 62℃ to obtain a product with a viscosity of 220 mPa·s. The active ingredient content of this product was 98%, and the pH value was 6.2. Cage-like Silsesquioxane: Phenyltrichlorosilane was dissolved in a toluene-ammonia water mixture (5.2:1 volume ratio), reacted at 0-5℃ for 4.5 hours, washed, and then vacuum dried at 62℃ for 8.5 hours to obtain an octaaminophenyl cage-like silsesquioxane with an amino content of 3.9 mmol / g. The particle size of this product was 65 nm, the thermal decomposition temperature was 450℃, and the char residue at 800℃ under a nitrogen atmosphere was 51%.

[0057] Coating Preparation S1. Graphene Modification: Hydroxylated graphene was added to deionized water at a solid-liquid ratio of 1:55 and sonicated at 480W for 50 minutes at a frequency of 26kHz. 12% (by weight of graphene) of bis(3-triethoxysilylpropyl) disulfide was added, and the mixture was stirred at 500r / min for 3.8 hours at 63℃, followed by vacuum freeze-drying at -45℃ and 5Pa for 16 hours. The moisture content of the dried material was 0.09%, its dispersion stability in xylene was 70 hours, and its sedimentation rate was 4.5%. S2. Premixing: Epoxy-modified silicone resin, silane-modified graphene, nano-zirconia-coated boron nitride, cage-like silsesquioxane, polyetheretherketone micropowder, nano-graphene oxide quantum dots, and modified montmorillonite were added to a planetary mixer and stirred at 2300r / min for 16 minutes, controlling the material temperature to not exceed 40℃ during stirring. S3. Melting Reaction: Add lanthanum isooctanoate-titanium ester composite coupling agent, fluorophosphate, curing agent, leveling agent, and defoamer to the mixture, mix thoroughly, and then feed it into a twin-screw extruder. Control the temperatures in zones 1 (92℃), 2 (118℃), 3 (118℃), and 4 (102℃), with a screw speed of 390 r / min, nitrogen flow rate of 0.65 L / min, oxygen content controlled at 0.45%, and material residence time in the extruder of 40 seconds. S4. Post-treatment: Cool the extrudate to room temperature using cooling rollers, crush it into 7mm particles, and feed it into an ultrafine pulverizer for cryogenic pulverization using liquid nitrogen at a pulverization temperature of -88℃ and a pulverization pressure of 0.72 MPa. After pulverization, pass it through a 230-mesh sieve. The sieved material is then vacuum dried at 42℃ for 2.2 hours to obtain a heavy-duty anti-corrosion powder coating. The powder has a particle size distribution (D50) of 35 μm, a particle size distribution span of 1.1, and a loose packing density of 0.45 g / cm³. 3 Flowability 23s / 100g.

[0058] Comparative Example

[0059] Raw material preparation: Prepare the following raw materials by weight: 45 parts of ordinary epoxy modified silicone resin (physical blend of E-51 epoxy resin and methyl phenyl silicone resin, mass ratio 4:1), 1.2 parts of unmodified graphene, 8 parts of boron nitride, 3 parts of silane coupling agent KH-550, 6 parts of dicyandiamide curing agent, 1 part of leveling agent, 0.5 parts of defoamer, and 3 parts of polytetrafluoroethylene micro powder.

[0060] Resin preparation: E-51 epoxy resin and methylphenyl silicone resin were directly mixed at a mass ratio of 4:1 and mechanically stirred for 30 minutes to obtain ordinary epoxy-modified organosilicon resin.

[0061] The pretreated unmodified graphene was used directly, with a sheet diameter of 1.8 μm and a thickness of 0.8 nm. Boron nitride was used directly, with a particle size of 30 nm.

[0062] Coating Preparation S1. Mixing: Add all raw materials to a mixer and mix at 1500 rpm for 15 minutes. S2. Melt Extrusion: Feed the mixture into a twin-screw extruder, control the temperature at 110-120℃, and the screw speed at 300 rpm, extruding under air atmosphere. S3. Post-treatment: After the extrudate cools, crush it using a conventional pulverizer, pass it through a 200-mesh sieve, and air dry it naturally to obtain the final product.

[0063] Performance test results table:

[0064]

[0065]

[0066] This table presents the advantages of the patented technical solution. Regarding adhesion, Examples 1-3 all achieve adhesion exceeding 8.3 MPa, as the epoxy-based resin strengthens the substrate bond through chemical bridging, and the composite coupling agent further enhances the interfacial interaction force; the comparative example's physically blended resin has weak bonding with the substrate, with an adhesion of only 5.2 MPa. In terms of salt spray resistance, the graphene-nano-coated powder barrier network constructed in the examples effectively blocks chloride ion penetration, achieving a salt spray resistance time exceeding 4800 hours; the comparative example's unmodified graphene agglomerates and forms defects, resulting in a salt spray resistance of only 1500 hours. Regarding mechanical properties and thermal stability, the cage-like silsesquioxane and modified montmorillonite in the examples enhance the crosslinking density, achieving an impact strength exceeding 5 kJ / m². 2 The thermal decomposition temperature exceeds 415℃; the comparative example lacks a synergistic reinforcement system, and the impact strength is 3.1 kJ / m. 2 The thermal decomposition temperature is only 350℃. The difference in coating appearance stems from the precise process control in the example, which avoids pinhole defects caused by poor powder dispersion in the comparative example.

[0067] Comparison table of process parameters:

[0068]

[0069]

[0070] This table reveals the root causes of performance differences through variations in process details, highlighting the scientific nature of the patent's process design. Regarding resin modification, the example demonstrates how chemical bridging enables stable chemical bonds between epoxy and silicone resins, resulting in superior compatibility and mechanical properties; the comparative example shows that physical blending easily leads to phase separation. In the graphene treatment stage, the example demonstrates how dual treatment with hydroxylation and silane modification improves dispersibility and ensures tight bonding with the resin; the comparative example shows severe agglomeration of untreated graphene, creating a performance bottleneck. Regarding nanoparticles, the example demonstrates how zirconium dioxide coated with boron nitride provides both barrier and wear-resistant properties; the comparative example shows that ordinary boron nitride has a single function. In the coupling agent system, the example demonstrates how a composite coupling agent is adapted to optimize the interfaces of multiple components; the comparative example shows that a single silane has limited effectiveness. In the extrusion and pulverization processes, the example demonstrates how nitrogen protection prevents resin oxidation, and liquid nitrogen cryogenic pulverization ensures uniform particle size; the comparative example shows that air atmosphere and room temperature pulverization result in poor powder quality, ultimately affecting coating performance.

[0071] Comparison table of coating resistance to media and durability:

[0072] Performance indicators Example 1 Example 2 Example 3 Comparative Example Resistant to 5% hydrochloric acid (1000h) Non-corrosive Non-corrosive Non-corrosive Surface pitting Resistant to 5% sodium hydroxide (1000h) Non-corrosive Non-corrosive Non-corrosive Edge bubbling Resistant to damp heat (5000h) No change No change Slight loss of light Large-scale peeling Resistant to accelerated aging (3000h) Loss rate 5% Loss rate 4% Loss rate 6% Loss rate 45% Coating hardness (pencil hardness) 3H 3H 2H H

[0073] This table verifies the practical value of the patented coating under corrosive and aging environments. Regarding acid and alkali resistance, the coating in the example, due to the hydrophobic modification of the fluorophosphate ester and its dense filler network, showed no corrosion after 1000 hours of acid and alkali immersion; the coating in the comparative example lacked density, resulting in pitting corrosion in acid and blistering at the edges in alkali. In terms of humid heat resistance, the cage-like silsesquioxane in the example increased the crosslinking density, preventing water molecule penetration, and showed no significant change after 5000 hours; the resin in the comparative example had poor hydrolysis resistance, leading to coating peeling from the substrate under humid heat conditions and large-area delamination. Regarding aging resistance, the silicone resin and nano-quantum dots in the example synergistically resisted ultraviolet radiation, with a gloss loss rate of only 4%-6% after 3000 hours; the comparative example lacked anti-aging design, and resin degradation resulted in a gloss loss rate of 45%. The difference in pencil hardness stemmed from the reinforcing effect of the nano-zirconia-coated boron nitride in the example, achieving a hardness of 2H-3H, far exceeding the H grade of the comparative example, making it more resistant to scratches and wear.

[0074] Comparison table of coating processing and application performance:

[0075] Performance indicators Example 1 Example 2 Example 3 Comparative Example Melt flowability (mm / 20min) 28 29 27 20 Curing time (180℃) 15min 14min 16min 20min Powder storage stability (6 months) No clumps No clumps No clumps Slight caking Coating thickness uniformity (deviation) ±2μm ±2μm ±3μm ±5μm Construction utilization rate 95％ 96％ 94％ 85％

[0076] This table demonstrates the industrial adaptability of this patented technology from a production and construction perspective. Regarding melt flowability, the leveling agent and optimized powder particle size distribution in the examples improve resin flowability by 27-29 mm; in the comparative example, unmodified powder agglomerates, hindering flow (only 20 mm), affecting coating levelability. Regarding curing time, the composite coupling agent in the examples also has a catalytic effect, curing in 14-16 minutes at 180℃; the comparative example's single curing system has low reactivity, requiring 20 minutes, reducing production efficiency. Regarding storage stability, the powder in the examples has uniform particle size and low moisture content (≤0.1%), showing no clumping after 6 months; the comparative example's coarse pulverization process results in a wide particle size distribution, making it prone to moisture absorption and clumping. Regarding coating thickness uniformity and application utilization, the powder in the examples has good flowability and a narrow particle size distribution, easily adhering evenly during application with a deviation of only ±2-3 μm and a utilization rate of 94%-96%; the comparative example's powder performance is unstable, with a thickness deviation of ±5 μm and a utilization rate of only 85%, increasing construction costs.

[0077] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating, characterized in that, By weight, it is composed of the following components: 42-58 parts of epoxy-modified silicone resin, 0.8-2.5 parts of hydroxylated graphene, 6-11 parts of nano-zirconia-coated boron nitride, 2.5-5.5 parts of lanthanum isooctanoate-titanium ester composite coupling agent, 1.5-3.5 parts of bis(3-triethoxysilylpropyl) disulfide, 4-7 parts of cage-like silsesquioxane, 5-8 parts of curing agent, 0.8-1.8 parts of leveling agent, 0.4-0.9 parts of defoamer, 2.5-4.5 parts of polyetheretherketone micro powder, and 1.2-2.8 parts of fluorinated phosphate ester; The epoxy-modified silicone resin is prepared by bridging epoxy resin and silicone resin with γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

2. The graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating according to claim 1, characterized in that, It also includes 0.2-0.9 parts of nano-graphene oxide quantum dots with a particle size of 4-9 nm, the surface of which contains both carboxyl and epoxy functional groups, with a carboxyl content of 0.8-1.5 mmol / g and an epoxy content of 0.5-1.2 mmol / g; the nano-graphene oxide quantum dots are prepared by nitric acid oxidation cutting of graphene nanosheets at an oxidation temperature of 120-140℃ for 6-8 hours, followed by dialysis purification and drying in a vacuum drying oven at 60-70℃ for 12-16 hours, resulting in a powder specific surface area of ​​300-500 m². 2 / g.

3. The graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating according to claim 1, characterized in that, It also includes 2.5-4.5 parts of modified montmorillonite, wherein the modified montmorillonite is subjected to composite intercalation treatment with hexadecyltrimethylammonium bromide and γ-aminopropyltriethoxysilane. The amount of hexadecyltrimethylammonium bromide is 15-25% of the mass of montmorillonite, and the amount of γ-aminopropyltriethoxysilane is 5-10% of the mass of montmorillonite. The treatment process is as follows: montmorillonite is added to deionized water, and hexadecyltrimethylammonium bromide and γ-aminopropyltriethoxysilane are added sequentially. The mixture is reacted at 80-90℃ for 3-4 hours, filtered, washed with deionized water until no bromide ions are detected, dried at 80-90℃ for 8-10 hours, pulverized, and passed through a 400-mesh sieve. The interlayer spacing after treatment is 2.5-4.5 nm.

4. The graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating according to claim 1, characterized in that, The hydroxylated graphene was prepared by the Hummers method and then reduced by hydroxylamine hydrochloride. In the Hummers method, the mass ratio of graphite to potassium permanganate was 1:3-1:5, the reaction temperature was 30-40℃, and the reaction time was 2-3 hours. During the reduction treatment, the amount of hydroxylamine hydrochloride was 30-50% of the mass of graphene oxide, the reduction temperature was 60-70℃, and the reduction time was 2-3 hours. After reduction, the graphene was washed with deionized water until neutral and then freeze-dried to obtain hydroxylated graphene.

5. The graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating according to claim 1, characterized in that, The nano-zirconia-coated boron nitride was prepared by a sol-gel method. The zirconia precursor was zirconium oxychloride, and the solvent was a mixture of ethanol and water with a volume ratio of 3:1-4:

1. The boron nitride powder had a particle size of 30-50 nm. The preparation process involved dispersing boron nitride in the solvent, ultrasonicating for 30-40 minutes, adding zirconium oxychloride solution and ammonia, adjusting the pH to 9-10, stirring at 50-60℃ for 2-3 hours, filtering, and washing until no chloride ions were found.

6. The graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating according to claim 1, characterized in that, In the lanthanum isooctanoate-titanium ester composite coupling agent, the mass ratio of lanthanum isooctanoate to titanate is 1:3.5-1:4.5, and the titanate is isopropyltris(dioctylpyrophosphoryloxy) titanate. The composite coupling agent is prepared by stirring lanthanum isooctanoate and titanate at 60-70℃ for 1-2 hours, with nitrogen gas purging during the reaction for protection, and cooling to room temperature after the reaction is completed.

7. The graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating according to claim 1, characterized in that, The cage-like silsesquioxane is an octaaminophenyl cage-like silsesquioxane, which is prepared by hydrolysis and condensation of phenyltrichlorosilane in a toluene and ammonia mixture. The volume ratio of toluene to ammonia is 5:1-6:1, the concentration of phenyltrichlorosilane is 0.1-0.2 mol / L, the reaction temperature is 0-5℃, and the reaction time is 4-6 hours. After the reaction, the mixture is filtered, washed successively with toluene and ethanol, and dried under vacuum at 60-70℃ for 8-10 hours.

8. The graphene-reinforced epoxy-modified organosilicon resin heavy-duty anti-corrosion powder coating according to claim 1, characterized in that, A method for preparing graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating includes the following steps: S1. Graphene modification: Hydroxylated graphene is added to deionized water at a solid-liquid ratio of 1:50-1:80 and ultrasonically dispersed for 45-75 minutes. Bis(3-triethoxysilylpropyl) disulfide is added at an amount of 10-20% of the graphene mass. The mixture is stirred at 62-68℃ for 3.5-4.5 hours at a stirring speed of 400-500 r / min. After the reaction is completed, the mixture is freeze-dried to obtain silane-modified graphene. S2. Premixing: Add epoxy-modified silicone resin, sulfide-modified graphene, nano-zirconia-coated boron nitride, cage-shaped silsesquioxane, and polyether ether ketone micro powder to a high-speed mixer according to the formula, and stir at 2200-2800 r / min for 16-19 minutes in a planetary mixer. During the stirring process, control the material temperature to not exceed 40℃. S3. Melting reaction: Add lanthanum isooctanoate-titanium ester composite coupling agent, fluorinated phosphate, curing agent, leveling agent, and defoamer to the mixture. After mixing evenly, feed it into a twin-screw extruder. Control the temperature of zone 1 to 90-100℃, zone 2 to 115-125℃, zone 3 to 115-125℃, and zone 4 to 100-110℃. The screw speed is 380-420 r / min. Maintain a nitrogen atmosphere during extrusion. S4. Post-treatment: Cool the extrudate to room temperature with cooling rollers, crush it into particles with a particle size of 5-10 mm, and feed it into an ultra-fine pulverizer for further pulverization. After pulverization, pass it through a 220-280 mesh sieve. After sieving, vacuum dry the material at 40-50℃ for 2-3 hours to obtain a heavy-duty anti-corrosion powder coating.

9. A graphene-reinforced epoxy-modified silicone resin heavy-duty anti-corrosion powder coating according to claim 8, characterized in that, The ultrasonic power in S1 is 450-550W, the ultrasonic frequency is 25-30kHz; the freeze-drying temperature is -45 to -48℃, the vacuum degree is 5-8Pa, the time is 15-21 hours, and the moisture content of the dried material is ≤0.1%; the dispersion stability of the modified graphene in xylene is ≥72 hours.

10. A graphene-reinforced epoxy-modified organosilicon resin heavy-duty anti-corrosion powder coating according to claim 8, characterized in that, In S3, the nitrogen flow rate is 0.6-0.9 L / min, the oxygen content is controlled below 0.5%, and the material residence time in the extruder is 30-60 seconds; in S4, the ultrafine pulverizer uses liquid nitrogen cryogenic pulverization, the pulverization temperature is -85 to -95℃, and the pulverization pressure is 0.7-0.8 MPa.

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