High-weather-resistance solvent-free coating and preparation method thereof

Abstract

The invention provides a high-weather-resistance solvent-free coating and a preparation method thereof, and belongs to the technical field of coatings. The modified graphene / aluminum oxide composite material is introduced to construct a complex three-dimensional cross-linked structure, the physical barrier effect of the coating is enhanced, the permeation path of a corrosive medium is prolonged, and therefore the weather resistance is improved. The barrier performance of the coating is further optimized through synergistic modification of resveratrol / montmorillonite, montmorillonite and graphene jointly act to form a compact barrier layer, resveratrol effectively inhibits oxidative degradation of an acrylic matrix by capturing free radicals, and the service life of the coating is prolonged. Besides, a fluorinated group and an organic silicon group are introduced into an acrylic resin chain, the fluorinated group endows the coating with excellent weather resistance, and the organic silicon group provides an additional barrier through a flexible network structure, so that invasion of a corrosive medium is further blocked. The durability and the protection performance of the coating are remarkably improved through the multi-protection mechanism, and the use requirement in a severe environment is met.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings and relates to a highly weather-resistant solvent-free coating and a preparation method thereof. Background Art

[0002] In the field of modern industry and construction, coatings are key protective materials, and their performance is directly related to the service life and safety of the substrate in complex environments. With the advancement of technology and the continuous improvement of society's requirements for environmental protection, the research and development of coatings is moving towards a more efficient, environmentally friendly and durable direction. Especially in the fields of harsh industrial equipment protection, building exterior wall decoration and marine protection, higher weather resistance, corrosion resistance and environmental adaptability requirements are put forward for coatings. Highly weather-resistant solvent-free coatings have become an important research direction of modern coatings technology due to their performance advantages.

[0003] Solvent-free coatings contain no or very little volatile organic compounds, which greatly reduces pollution to the environment and complies with increasingly stringent environmental regulations around the world. At the same time, their low odor, fast curing and excellent coating properties during construction make them an ideal choice for widespread use in industrial and architectural coatings. This type of coating not only exhibits excellent mechanical properties and chemical stability, but also has outstanding performance in corrosion resistance, aging resistance and long-term weather resistance. Therefore, it is widely used in protective coatings for industrial equipment, decorative coatings for building exteriors, and anti-corrosion coatings in marine environments.

[0004] Acrylic resin has become an indispensable base material in modern coating systems due to its excellent comprehensive properties. Its outstanding gloss retention ability and flexible molecular structure design make it occupy an important position in architectural coatings and industrial coatings. However, traditional acrylic resin coatings also face challenges in application: in an environment with high ultraviolet radiation, it is prone to photoaging, resulting in surface cracking and gloss loss. This problem seriously limits the performance of traditional acrylic resin coatings in demanding application scenarios. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a highly weather-resistant solvent-free coating and a preparation method thereof. The barrier properties of the coating are improved by composite modification of graphene and aluminum oxide nanoparticles, and the coating is also endowed with excellent mechanical strength and chemical corrosion resistance; the introduced montmorillonite is cationically modified, and the complex formed with resveratrol further enhances the coating's resistance to ultraviolet aging and oxidation resistance; perfluorooctane sulfonyl fluoride and bisaminopropyl polydimethylsiloxane are reacted to generate fluorinated organosilicon compounds, which are introduced into acrylic resins to form a large number of low-surface-energy fluorinated structures on the resin chains, and at the same time, the flexibility and adhesion of the coating are enhanced through the flexible network of organosilicon groups. The introduction of fluorinated groups also significantly improves the hydrophobicity, chemical corrosion resistance and anti-pollution properties of the coating, making it exhibit excellent weather resistance in harsh environments.

[0006] To achieve this object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for preparing a highly weather-resistant solvent-free coating, the method for preparing the highly weather-resistant solvent-free coating comprising: S1: adding graphite and sodium nitrate to sulfuric acid in an ice water bath, then adding potassium permanganate to obtain reaction solution A, reacting at a constant temperature to obtain reaction solution B, adding hydrogen peroxide, washing, and freeze-drying to obtain graphene; adding graphene and imidazole to deionized water, then adding alumina nanoparticles to obtain reaction solution C, ultrasonicating and reacting to obtain reaction solution D, filtering, washing, and drying to obtain modified graphene / alumina; S2: adding montmorillonite to a dimethyldiallyl ammonium chloride solution to obtain a dispersion, filtering, washing, and drying after the reaction to obtain a modified montmorillonite; preparing a resveratrol ethanol solution, adding the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, stirring the mixture to obtain a reaction solution E, centrifuging, washing, and freeze-drying to obtain resveratrol / montmorillonite; S3: adding triethylamine to toluene, adding bisaminopropyl polydimethylsiloxane and perfluorooctane sulfonyl fluoride to obtain a reaction solution F, reacting at a constant temperature to obtain a pre-treated reaction solution, washing with a saturated sodium chloride solution and vacuum drying to obtain a modified liquid, adding acrylic resin to the mixture to obtain a fluorinated acrylic resin; S4: Mix the fluorinated acrylic resin with the curing agent, then add the modified graphene / alumina, resveratrol / montmorillonite, and the additive, stir evenly, and obtain a highly weather-resistant solvent-free coating.

[0007] As a preferred technical solution of the present invention, in step S1, the mass ratio of graphite to sodium nitrate is 1:(0.5-1), for example, it can be 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95 or 1:1.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0008] In some optional examples, the feeding ratio of graphite to sulfuric acid is 1g / 35-45mL, for example, it can be 1g:35mL, 1g:36mL, 1g:37mL, 1g:38mL, 1g:39mL, 1g:40mL, 1g:41mL, 1g:42mL, 1g:43mL, 1g:44mL or 1g:45mL, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0009] In some optional examples, the mass ratio of graphite to potassium permanganate is 1:(4-5), for example, it can be 1:4.0, 1:4.1, 1:4.2, 1:4.3, 1:4.4, 1:4.5, 1:4.6, 1:4.7, 1:4.8, 1:4.9 or 1:5.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0010] In some optional examples, the temperature of the constant temperature reaction of the reaction liquid A is 80-90°C, for example, it can be 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C or 90°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0011] In some optional examples, the isothermal reaction time of the reaction liquid A is 1-2 h, for example, 1.0 h, 1.1 h, 1.2 h, 1.3 h, 1.4 h, 1.5 h, 1.6 h, 1.7 h, 1.8 h, 1.9 h or 2.0 h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0012] In some optional examples, the molar ratio of potassium permanganate to hydrogen peroxide is 1:(1-1.5), for example, it can be 1:1.0, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45 or 1:1.5, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0013] In some optional examples, the concentration of graphene is 0.5-1 mg / mL, for example, it can be 0.5 mg / mL, 0.55 mg / mL, 0.6 mg / mL, 0.65 mg / mL, 0.7 mg / mL, 0.75 mg / mL, 0.8 mg / mL, 0.85 mg / mL, 0.9 mg / mL, 0.95 mg / mL or 1.0 mg / mL, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] In some optional examples, the mass ratio of graphene to imidazole is 1:(5-10), for example, it can be 1:5.0, 1:5.5, 1:6.0, 1:6.5, 1:7.0, 1:7.5, 1:8.0, 1:8.5, 1:9.0, 1:9.5 or 1:10.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] In some optional examples, the mass ratio of the graphene to the aluminum oxide nanoparticles is 1:(0.5-1), for example, it can be 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95 or 1:1.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] As a preferred technical solution of the present invention, in step S2, the mass ratio of montmorillonite to dimethyldiallylammonium chloride is 1:(0.5-1), for example, it can be 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95 or 1:1.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] In some optional examples, the mass fraction of the dimethyldiallylammonium chloride solution is 5-10wt.%, for example, it can be 5.0wt.%, 5.5wt.%, 6.0wt.%, 6.5wt.%, 7.0wt.%, 7.5wt.%, 8.0wt.%, 8.5wt.%, 9.0wt.%, 9.5wt.% or 10.0wt.%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In some optional examples, the dispersion reaction temperature is 60-70°C, for example, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] In some optional examples, the reaction time of the dispersion is 1-2h, for example, 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In some optional examples, the mass fraction of the resveratrol ethanol solution is 1-5wt.%, for example, it can be 1.0wt.%, 1.5wt.%, 2.0wt.%, 2.5wt.%, 3.0wt.%, 3.5wt.%, 4.0wt.%, 4.5wt.% or 5.0wt.%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] In some optional examples, the mass ratio of resveratrol to modified montmorillonite is 1:(1-5), for example, it can be 1:1.0, 1:1.5, 1:2.0, 1:2.5, 1:3.0, 1:3.5, 1:4.0, 1:4.5 or 1:5.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] In some optional examples, the rotation speed of the stirring reaction of the composite solution is 500-600rpm, for example, it can be 500rpm, 510rpm, 520rpm, 530rpm, 540rpm, 550rpm, 560rpm, 570rpm, 580rpm, 590rpm or 600rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] In some optional examples, the stirring reaction time of the composite solution is 2-4h, for example, it can be 2.0h, 2.2h, 2.4h, 2.6h, 2.8h, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h or 4.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] As a preferred technical solution of the present invention, in step S3, the concentration of triethylamine in toluene is 2-3 mol / L, for example, it can be 2.0 mol / L, 2.1 mol / L, 2.2 mol / L, 2.3 mol / L, 2.4 mol / L, 2.5 mol / L, 2.6 mol / L, 2.7 mol / L, 2.8 mol / L, 2.9 mol / L or 3.0 mol / L, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] In some optional examples, the molar ratio of the bisaminopropyl polydimethylsiloxane to triethylamine is 1:(1-3), for example, it can be 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, 1:2.2, 1:2.4, 1:2.6, 1:2.8 or 1:3.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] In some optional examples, the molar ratio of perfluorooctane sulfonyl fluoride to bisaminopropyl polydimethylsiloxane is 1:(1-2), for example, it can be 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] In some optional examples, the temperature of the constant temperature reaction of the reaction liquid F is 50-60°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] In some optional examples, the constant temperature reaction time of the reaction liquid F is 2-4h, for example, it can be 2.0h, 2.2h, 2.4h, 2.6h, 2.8h, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h or 4.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] In some optional examples, the mass ratio of the bisaminopropyl polydimethylsiloxane to the acrylic resin is 1:(10-20), for example, it can be 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] In some optional examples, the curing agent is hexamethylene diisocyanate trimer or isophorone diisocyanate trimer; The auxiliary agent includes an emulsifier, a leveling agent and a defoamer; wherein the emulsifier is OP-100 or PEG-400; The leveling agent is Byk-306 or perfluoroalkyl ester FC430; the defoaming agent is silicone defoaming agent or FoamStar SI2210.

[0031] In a second aspect, the present invention provides a highly weather-resistant solvent-free coating, wherein the highly weather-resistant solvent-free coating comprises the following components in parts by weight: 50-80 parts of fluorinated acrylic resin; Modified graphene / aluminum oxide 5-15 parts; Resveratrol / montmorillonite 3-10 parts; 10-20 parts of curing agent; 2-5 parts of additives; The auxiliary agents include emulsifier, leveling agent and defoamer, wherein the emulsifier is 1-3 parts, the leveling agent is 0.5-1 parts and the defoamer is 0.5-1 parts.

[0032] In some optional examples, the mass parts of the fluorinated acrylic resin is 50-80 parts, for example, it can be 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts or 80 parts, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are equally applicable.

[0033] In some optional examples, the mass proportion of modified graphene / aluminum oxide is 5-15 parts, for example, it can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] In some optional examples, the mass proportion of resveratrol / montmorillonite is 3-10 parts, for example, it can be 3.0 parts, 3.5 parts, 4.0 parts, 4.5 parts, 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts, 8.0 parts, 8.5 parts, 9.0 parts, 9.5 parts or 10.0 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] In some optional examples, the mass proportion of the curing agent is 10-20 parts, for example, it can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] In some optional examples, the mass proportion of the auxiliary agent is 2.2-5 parts, for example, it can be 2.2 parts, 2.5 parts, 3 parts, 3.0 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4.0 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts or 5 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] In some optional examples, the mass proportion of the emulsifier is 2-4 parts, for example, it can be 2.0 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3.0 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts or 4.0 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] In some optional examples, the mass proportion of the leveling agent is 0.1-0.5 parts, for example, it can be 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts or 0.5 parts, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] In some optional examples, the mass fraction of the defoaming agent is 0.5-1 part, for example, it can be 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, 0.35 part, 0.4 part, 0.45 part or 0.5 part, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] The present invention introduces graphene to modify acrylic resin. Graphene has a unique two-dimensional layered structure and a wide range of π-π conjugated systems, and has excellent absorption and shielding effects on ultraviolet rays, which can effectively reduce the damage of ultraviolet rays to the acrylic resin matrix, thereby inhibiting the photodegradation phenomenon caused by ultraviolet rays, improving the aging resistance of the coating, and extending the service life. In addition, the high chemical inertness and excellent electrochemical stability of graphene can effectively resist the occurrence of oxidation reactions, reduce the erosion of the coating by corrosive factors such as oxides, and keep the coating stable in a complex environment.

[0041] The flaky structure of graphene forms a highly dense barrier layer in the coating, which can effectively block the penetration of moisture, oxygen and chemical corrosive substances. This barrier effect significantly enhances the anti-corrosion performance of the coating, and is particularly suitable for applications with extremely high requirements for corrosion resistance, such as marine equipment and chemical pipeline coatings. The high thermal conductivity of graphene can also disperse the heat on the coating surface, reduce heat-induced performance degradation, and make the coating show better stability in high-temperature environments.

[0042] At the same time, graphene, as an excellent reinforcing filler in coatings, gives the coatings higher mechanical strength, wear resistance and impact resistance through its interlamellar interactions and strong interfacial effects, enabling it to maintain excellent performance for a long time even under harsh conditions in heavy industry, transportation and other fields.

[0043] The present invention introduces alumina and graphene to give full play to the synergistic effect of the two in the coating system. Alumina particles are combined with graphene sheets to form a complex three-dimensional cross-linked structure, making the physical barrier inside the coating more compact. This structure can significantly extend the penetration path of corrosive media (such as water, oxygen and ions), greatly improve the barrier performance of the coating, and thus enhance the anti-corrosion effect of the coating, which is particularly suitable for long-term protection needs in harsh environments.

[0044] At the same time, graphene is prone to agglomeration in coatings due to its strong van der Waals force and large specific surface area, which affects the uniformity and performance of the coating. By compounding with alumina, the agglomeration tendency of graphene in the coating system can be effectively reduced, making it more evenly dispersed in the matrix, ensuring the consistency and stability of the coating performance. The surface of alumina has abundant hydroxyl groups, and its compatibility with the acrylic resin matrix can be further improved through chemical modification, thereby enhancing the dispersion stability of graphene and the adhesion performance of the coating. In addition, the introduction of alumina can also effectively reduce the viscosity of the coating, improve the construction performance, and adapt to different coating process requirements.

[0045] As an inorganic material, alumina has excellent thermal stability. Its combination with graphene can further improve the coating's tolerance under high temperature conditions. For example, when the coating is exposed to high temperature or thermal shock, the composite material can reduce thermal degradation and performance decay, and maintain the physical and chemical integrity of the coating. At the same time, the high thermal conductivity of alumina combined with the excellent thermal conductivity of graphene can improve the coating's heat dissipation capacity and reduce the surface temperature of the substrate, thereby playing a role in thermal insulation protection. This makes the coating show more excellent stability and protection effect in high temperature environments.

[0046] The present invention modifies acrylic resin by introducing montmorillonite. The montmorillonite lamella structure can be evenly dispersed in the coating matrix to form a nano-enhancement effect, thereby greatly improving the mechanical properties of the coating. Due to the high rigidity and strong interface force of the lamella, it can effectively prevent the coating from cracking or breaking when subjected to external mechanical stress, so that the coating exhibits better tolerance in terms of impact resistance and tensile resistance. In addition, the lamella structure can also absorb and disperse external impact energy, reduce local stress concentration, and thus significantly reduce the risk of coating damage.

[0047] The lamellar structure of montmorillonite can also significantly extend the penetration path of corrosive media (such as water, oxygen and ions) through the "maze effect". The high lateral specific surface area and arrangement of the lamellar layers form complex physical barriers in the coating, forcing the corrosive media to diffuse "tortuously" within the coating. This effect not only effectively inhibits the penetration rate of the corrosive media, but also reduces its direct erosion of the substrate, thereby greatly improving the anti-corrosion performance of the coating. Especially in high humidity or acid-base environments, this barrier effect can extend the service life of the coating.

[0048] In addition, the introduction of montmorillonite also has a positive effect on the heat resistance and aging resistance of the coating. The high thermal stability of montmorillonite makes the coating show higher thermal degradation resistance in high temperature environment, reducing the performance degradation caused by temperature fluctuations. In addition, the lamellar structure can also shield the destructive effect of ultraviolet rays on the coating, thereby improving the anti-aging performance of the coating and making it show a more lasting protective effect in long-term outdoor use.

[0049] Montmorillonite is modified using dimethyldiallyl ammonium chloride. This modification process overcomes the disadvantages of montmorillonite, which is that it is highly hydrophilic and difficult to be well compatible with organic systems such as acrylic resin. As a cationic quaternary ammonium salt, dimethyldiallyl ammonium chloride can embed its cations into the interlayer structure of montmorillonite through the exchange reaction between cations and montmorillonite layers, thereby realizing the transformation of montmorillonite from hydrophilicity to hydrophobicity or organophilicity. The modified montmorillonite exhibits better organophilicity and significantly enhances its compatibility with the acrylic resin matrix, which helps to improve the overall mechanical properties and adhesion of the coating.

[0050] In addition, the quaternary ammonium salt structure introduced during the modification of dimethyldiallylammonium chloride also gives montmorillonite certain antistatic properties. In coatings, this property helps to reduce the electrostatic deposition effect on the coating surface, thereby reducing the adsorption of particles such as dust and pollutants. This not only improves the surface finish of the coating, but also improves the decorative effect and cleaning performance of the coating, making it very suitable for coating application scenarios with high requirements for appearance.

[0051] At the same time, the interlayer spacing of the modified montmorillonite is significantly increased, and the originally tightly stacked lamellar structure is effectively separated, which makes the dispersion of montmorillonite in the coating more uniform, avoiding the local performance degradation caused by lamellar agglomeration. The evenly dispersed montmorillonite flakes can form a more continuous "maze effect" barrier in the coating, thereby further extending the penetration path of the corrosive medium and improving the corrosion resistance and barrier performance of the coating.

[0052] Resveratrol is used to compound with montmorillonite. Resveratrol is a natural polyphenol compound with phenolic hydroxyl groups in its molecules and has strong antioxidant activity. By introducing resveratrol into the interlayer structure or surface of montmorillonite, it can effectively capture free radicals, reduce the oxidative degradation of the acrylic matrix, and extend the service life of the coating; at the same time, resveratrol has natural antibacterial activity and can inhibit the spread of bacterial flora by interfering with microbial metabolism and inhibiting its growth and reproduction. After combining with montmorillonite, the formed composite material exhibits more excellent antibacterial properties. The lamellar structure of montmorillonite can provide a stable physical carrier for resveratrol, ensuring the uniform distribution and continuous release of its antibacterial components. This antibacterial composite material is particularly suitable for humid or corrosive environments, can effectively reduce the growth of microorganisms, prevent mildew or biological corrosion on the coating surface, and improve the applicability and durability of the coating.

[0053] There is also a synergistic effect between montmorillonite and graphene: both montmorillonite and graphene have a lamellar structure, but each has its own advantages in characteristics and functions. Graphene flakes are denser and have excellent barrier properties and mechanical strength, while montmorillonite flakes have a larger specific surface area and good physical barrier properties. Combining montmorillonite with graphene can achieve complementary advantages: montmorillonite fills the gaps between graphene flakes, effectively improving the barrier properties of the coating and forming a denser barrier layer. This composite structure can significantly reduce the penetration rate of moisture, oxygen and corrosive media, thereby improving the anti-corrosion performance and long-term weather resistance of the coating.

[0054] In terms of mechanical properties, the combination of montmorillonite and graphene also shows significant complementary advantages. Montmorillonite provides macroscopic structural support, which can increase the rigidity and dimensional stability of the coating, while graphene enhances the microscopic mechanical properties of the composite coating, such as tensile strength, toughness and wear resistance. The two work together to achieve a balance between strength and toughness in the composite coating, which can not only resist external impact, but also effectively prevent cracking and peeling of the coating, extending the service life of the coating.

[0055] Graphene is prone to agglomeration due to the strong van der Waals forces between its layers, which reduces its dispersion and uniformity in the coating. This problem has been significantly improved by combining it with montmorillonite. The intercalation effect of montmorillonite can effectively reduce the accumulation of graphene sheets and make their distribution more uniform, thereby improving the dispersion and stability of the composite material. In addition, montmorillonite can enhance its compatibility with the acrylic resin matrix through surface modification (such as organic treatment or grafting modification). The intercalation structure of the modified montmorillonite provides additional support for graphene and forms a good interface bonding, which improves the dispersion effect of graphene in the matrix and significantly enhances the adhesion of the coating.

[0056] This synergistic effect not only improves the barrier and mechanical properties of the coating, but also gives the coating more functions. For example, the conductive properties of graphene can give the coating certain antistatic properties, while the high thermal stability of montmorillonite enhances the high temperature resistance of the coating. The composite coating combining the two shows comprehensive advantages in corrosion resistance, wear resistance, high temperature resistance and aging resistance, making it have broad application prospects in industrial coatings, protective coatings and functional coatings.

[0057] The present invention modifies acrylic resin by introducing fluorinated groups. Perfluorooctane sulfonyl fluoride is used as a fluorination agent to react with bisaminopropyl polydimethylsiloxane to generate a fluorinated organosilicon compound, which contains both fluorinated groups and organosilicon groups in its molecular structure. The compound is then combined with acrylic resin. A large number of fluorine atoms are introduced into the acrylic resin chain. The introduction of fluorine atoms forms a fluorinated structure with extremely low surface energy, which significantly enhances the hydrophobicity, oleophobicity and anti-pollution properties of the resin, so that the coating can effectively prevent the adhesion of moisture, oil stains and dust, while greatly improving the cleaning convenience and anti-pollution performance.

[0058] In addition, the fluorinated group has excellent chemical inertness and high weather resistance, and its resistance to chemical corrosion and ultraviolet rays is greatly improved. This modification enables the coating to perform well in harsh environments, such as resisting aging or yellowing caused by acid and alkali solutions, salt spray, and long-term exposure to sunlight. The modified acrylic resin coating also has self-cleaning properties due to its extremely low surface energy, and is suitable for occasions that require high durability and aesthetics.

[0059] The introduction of bis-aminopropyl polydimethylsiloxane embeds flexible silicon-oxygen bonds in the molecular structure, thereby further improving the performance of the resin. On the one hand, the flexibility of the silicon-oxygen bonds improves the toughness of the resin, making the coating more elastic and resistant to cracking when responding to external impact or temperature changes; on the other hand, the introduction of this structure also improves the surface smoothness of the coating, reduces the occurrence of adhesion, and gives the acrylic resin better flexibility and surface adjustment performance.

[0060] There is also a synergistic effect between the organic silicon group and the fluorinated group introduced at the same time: the fluorinated group reduces the surface energy of the coating surface, making the coating film self-cleaning. This extremely low surface energy can effectively prevent the adhesion of dust, water stains and oil stains, allowing the coating to remain clean for a long time in various application scenarios and reduce maintenance costs. The organic silicon group further enhances the lubricity and surface smoothness of the coating film, making the coating surface smoother and more uniform, which not only improves the visual and tactile texture, but also makes cleaning and maintenance more convenient.

[0061] Secondly, fluorinated acrylic resins exhibit extremely high chemical inertness to water, acids, alkalis, and salt solutions. This property enables the coating to remain stable for a long time in a corrosive environment, avoiding aging, peeling, or failure due to chemical corrosion. The flexible network structure formed by the silicone group provides an additional physical barrier for the coating, which can effectively block the penetration of corrosive media, thereby further enhancing the protective effect of the coating. This dual protection mechanism improves the durability of the coating.

[0062] At the same time, the synergistic effect of the silicone group and the fluorinated group greatly improves the interfacial compatibility between the resin and inorganic materials (such as modified graphene / alumina, resveratrol / montmorillonite) by reducing the polarity of the acrylic resin. In the composite coating system, the modified resin can more evenly coat the inorganic filler to form a stable dispersion system, avoid the agglomeration of inorganic materials, and further improve the mechanical properties and functional stability of the composite coating.

[0063] Compared with the prior art, the present invention has the following beneficial effects: (1) Introducing modified graphene / alumina composite materials to form a complex three-dimensional cross-linked structure, making the physical shielding inside the coating denser and extending the penetration path of the corrosive medium, thereby enhancing the weather resistance of the coating; (2) Introducing resveratrol / montmorillonite to modify acrylic resin: Montmorillonite and graphene work synergistically to effectively improve the barrier properties of the coating and form a denser barrier layer; the introduction of resveratrol can effectively capture free radicals, reduce the oxidative degradation of the acrylic matrix, and extend the service life of the coating; (3) By introducing fluorinated groups and silicone groups into the acrylic resin chain, the high weather resistance of the fluorinated groups makes the coating perform better in harsh environments, and the flexible network structure formed by the silicone groups provides an additional physical barrier for the coating, which can effectively block the penetration of corrosive media, thereby further enhancing the protective effect of the coating. This dual protection mechanism improves the durability of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 A flow chart of a method for preparing a highly weather-resistant solvent-free coating provided in Example 1 of the present invention; Figure 2 Infrared spectra of graphene and imidazole-modified graphene provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0065] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0066] The chemical reagents used in the examples and comparative examples of the present invention are all commercially available products, and their brands, specifications, manufacturers and other information are as follows: Graphite: purchased from Ulanqab Dasheng Graphite New Materials Co., Ltd.; Sodium nitrate: purity ≥99%, purchased from Shandong Xinhao Chemical Co., Ltd.; Sulfuric acid: purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.; Potassium permanganate: purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.; Hydrogen peroxide: purity ≥30%, purchased from Sinopharm Chemical Reagent Co., Ltd.; Imidazole: purity ≥99%, purchased from Jiangsu Kanglejia Materials Co., Ltd.; Alumina nanoparticles: particle size 30-50 nm, purchased from Suzhou Baird New Material Technology Co., Ltd.; Montmorillonite: purchased from Sinopharm Chemical Reagent Co., Ltd. Dimethyldiallylammonium chloride: purity 65±1%, purchased from Zhejiang Xinhaitian Biotechnology Co., Ltd.; Resveratrol: purity ≥98%, purchased from Dongming Grus Biotechnology Co., Ltd.; Anhydrous ethanol: purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.; Triethylamine: purity ≥99%, purchased from Shandong Liding Chemical Technology Co., Ltd.; Toluene: purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.; Bisaminopropyl polydimethylsiloxane: MW = 1000, purchased from Beijing Bailingwei Technology Co., Ltd.; Perfluorooctane sulfonyl fluoride: purity ≥90%, purchased from Wuhan Haide Chemical Development Co., Ltd.; Sodium chloride: purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.; Acrylic resin: purchased from Guangdong Kelisen Resin Co., Ltd.; Hexamethylene diisocyanate trimer: purchased from Zichuan Biochemical Technology (Suzhou) Co., Ltd.; Isophorone diisocyanate trimer: purity ≥99%, purchased from Wanhua Chemical Group Co., Ltd.; OP-100: purity ≥99%, purchased from Zibo Haijie Chemical Co., Ltd.; PEG-400: purchased from Jiangsu Dena Chemical Co., Ltd.; Byk-306: purchased from Dongyang Chemical (Hong Kong) Co., Ltd.; Perfluoroalkyl ester FC430: purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.; Silicone defoamer: purchased from Guangdong Nanhui New Materials Co., Ltd. FoamStar SI 2210: purchased from BASF SE;

[0067] Example 1

[0068] like Figure 1 As shown, this embodiment provides a highly weather-resistant solvent-free coating and a preparation method thereof, wherein the highly weather-resistant solvent-free coating comprises the following components in parts by weight: 65 parts of fluorinated acrylic resin; Modified graphene / alumina 10 parts; Resveratrol / montmorillonite 7 parts; 15 parts of curing agent; 3.35 parts of additives; The auxiliary agents include emulsifier, leveling agent and defoamer, wherein the emulsifier is 2 parts, the leveling agent is 0.7 parts and the defoamer is 0.85 parts.

[0069] The preparation method specifically comprises the following steps: S1: Add graphite and sodium nitrate to sulfuric acid in an ice water bath. The mass ratio of graphite to sodium nitrate is 1:1; the feed ratio of graphite to sulfuric acid is 1g / 35mL, followed by potassium permanganate, the mass ratio of graphite to potassium permanganate is 1:4, to obtain reaction solution A, after constant temperature reaction at 80°C for 2h, obtain reaction solution B, add hydrogen peroxide, the molar ratio of potassium permanganate to hydrogen peroxide is 1:1, after washing and freeze drying, obtain graphene; add graphene and imidazole to deionized water, wherein the concentration of graphene is 0.8mg / mL; the mass ratio of graphene to imidazole is 1:8, then add alumina nanoparticles, the mass ratio of graphene to alumina is 1:1, obtain reaction solution C, ultrasonicate and react to obtain reaction solution D, filter, wash and dry to obtain modified graphene / alumina; wherein the infrared spectra of graphene and imidazole modified graphene are as follows Figure 2As shown: In the infrared spectrum of graphene, 3450cm -1 Corresponding to the stretching vibration of -OH; 1650cm -1 Corresponding to the C=O stretching vibration; 1085cm -1 The peak at 1500cm corresponds to the stretching vibration of CO. -1 The stretching vibration of CN is at 1069cm -1 The signal peak is NH, which indicates that imidazole has a covalent reaction with graphene.

[0070] S2: adding montmorillonite to a dimethyldiallyl ammonium chloride solution with a mass fraction of 8wt.% to obtain a dispersion, wherein the mass ratio of montmorillonite to dimethyldiallyl ammonium chloride is 1:0.8, reacting at 65°C for 2h, filtering, washing, and drying to obtain modified montmorillonite; preparing a resveratrol ethanol solution with a mass fraction of 4wt.%, adding the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, wherein the mass ratio of resveratrol to the modified montmorillonite is 1:3.8, stirring to react to obtain a reaction solution E, wherein the stirring reaction speed is 570rpm; the reaction time is 3h, centrifuging, washing, and freeze-drying to obtain resveratrol / montmorillonite; S3: adding triethylamine to toluene, the concentration of triethylamine being 2.5 mol / L, adding bisaminopropyl polydimethylsiloxane in a molar ratio of 1:2 to triethylamine and perfluorooctane sulfonyl fluoride in a molar ratio of 1:1.5 to bisaminopropyl polydimethylsiloxane to obtain a reaction solution F, reacting at a constant temperature of 50° C. for 3 h to obtain a pretreated reaction solution, washing with a saturated sodium chloride solution and vacuum drying to obtain a modified liquid, adding acrylic resin to the mixture to obtain a fluorinated acrylic resin, wherein the mass ratio of bisaminopropyl polydimethylsiloxane to acrylic resin is 1:10; S4: Mix the fluorinated acrylic resin with the curing agent, then add the modified graphene / alumina, resveratrol / montmorillonite, OP-100, Byk-306, and silicone defoamer, stir evenly, and obtain a highly weather-resistant solvent-free coating.

[0071] Example 2 This embodiment provides a highly weather-resistant solvent-free coating and a preparation method thereof, wherein the highly weather-resistant solvent-free coating comprises the following components in parts by weight: 50 parts of fluorinated acrylic resin; Modified graphene / alumina 5 parts; Resveratrol / montmorillonite 8.5 parts; 18 parts of curing agent; 4 parts of additives; The auxiliary agents include emulsifier, leveling agent and defoamer, wherein the emulsifier is 2.4 parts, the leveling agent is 0.85 parts and the defoamer is 0.75 parts.

[0072] The preparation method specifically comprises the following steps: S1: Add graphite and sodium nitrate to sulfuric acid in an ice-water bath. The mass ratio of graphite to sodium nitrate is 1:0.5; the feed ratio of graphite to sulfuric acid is 1g / 40mL, followed by potassium permanganate, the mass ratio of graphite to potassium permanganate is 1:4.2, to obtain reaction solution A, and react at 90°C for 1h to obtain reaction solution B, add hydrogen peroxide, the molar ratio of potassium permanganate to hydrogen peroxide is 1:1.2, and obtain graphene after washing and freeze-drying; add graphene and imidazole to deionized water, wherein the concentration of graphene is 0.5mg / mL; the mass ratio of graphene to imidazole is 1:5, and then add aluminum oxide nanoparticles, the mass ratio of graphene to aluminum oxide is 1:0.5, to obtain reaction solution C, ultrasonic and react to obtain reaction solution D, filter, wash, and dry to obtain modified graphene / alumina; S2: adding montmorillonite to a 10wt.% dimethyldiallyl ammonium chloride solution to obtain a dispersion, wherein the mass ratio of montmorillonite to dimethyldiallyl ammonium chloride is 1:0.5, reacting at 70°C for 1h, filtering, washing, and drying to obtain modified montmorillonite; preparing a 1wt.% resveratrol ethanol solution, adding the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, wherein the mass ratio of resveratrol to the modified montmorillonite is 1:3, stirring to react to obtain a reaction solution E, wherein the stirring reaction speed is 550rpm; the time is 2h, centrifuging, washing, and freeze-drying to obtain resveratrol / montmorillonite; S3: adding triethylamine to toluene, the concentration of triethylamine being 3 mol / L, adding bisaminopropyl polydimethylsiloxane in a molar ratio of 1:1 to triethylamine and perfluorooctane sulfonyl fluoride in a molar ratio of 1:2 to bisaminopropyl polydimethylsiloxane to obtain a reaction solution F, reacting at a constant temperature of 60° C. for 4 h to obtain a pretreated reaction solution, washing with a saturated sodium chloride solution and vacuum drying to obtain a modified liquid, adding acrylic resin to the mixture to obtain a fluorinated acrylic resin, wherein the mass ratio of bisaminopropyl polydimethylsiloxane to acrylic resin is 1:18; S4: The fluorinated acrylic resin and the curing agent are mixed, and then the modified graphene / alumina, resveratrol / montmorillonite, PEG-400, perfluoroalkyl ester FC430, and FoamStar SI 2210 are added and stirred evenly to obtain a highly weather-resistant solvent-free coating.

[0073] Example 3

[0074] This embodiment provides a highly weather-resistant solvent-free coating and a preparation method thereof, wherein the highly weather-resistant solvent-free coating comprises the following components in parts by weight: 75 parts of fluorinated acrylic resin; Modified graphene / alumina 12 parts; Resveratrol / montmorillonite 3 parts; 10 parts of curing agent; 2 parts of auxiliary agent; The auxiliary agents include emulsifier, leveling agent and defoamer, wherein the emulsifier is 1 part, the leveling agent is 0.5 part and the defoamer is 0.5 part.

[0075] The preparation method specifically comprises the following steps: S1: Add graphite and sodium nitrate to sulfuric acid in an ice-water bath. The mass ratio of graphite to sodium nitrate is 1:0.8; the feed ratio of graphite to sulfuric acid is 1g / 42mL, followed by potassium permanganate, the mass ratio of graphite to potassium permanganate is 1:4.5, to obtain reaction solution A, and react at 85°C for 1.5h to obtain reaction solution B, add hydrogen peroxide, the molar ratio of potassium permanganate to hydrogen peroxide is 1:1.4, and obtain graphene after washing and freeze-drying; add graphene and imidazole to deionized water, wherein the concentration of graphene is 0.89mg / mL; the mass ratio of graphene to imidazole is 1:10, and then add aluminum oxide nanoparticles, the mass ratio of graphene to aluminum oxide is 1:0.82, to obtain reaction solution C, ultrasonic and react to obtain reaction solution D, filter, wash, and dry to obtain modified graphene / alumina; S2: adding montmorillonite to a 5wt.% dimethyldiallyl ammonium chloride solution to obtain a dispersion, wherein the mass ratio of montmorillonite to dimethyldiallyl ammonium chloride is 1:1, reacting at 60°C for 1.5h, filtering, washing, and drying to obtain modified montmorillonite; preparing a 5wt.% resveratrol ethanol solution, adding the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, wherein the mass ratio of resveratrol to the modified montmorillonite is 1:1, stirring to react to obtain a reaction solution E, wherein the stirring reaction speed is 600rpm; the reaction time is 4h, centrifuging, washing, and freeze-drying to obtain resveratrol / montmorillonite; S3: adding triethylamine to toluene, the concentration of triethylamine being 2 mol / L, adding bisaminopropyl polydimethylsiloxane in a molar ratio of 1:2.4 to triethylamine and perfluorooctane sulfonyl fluoride in a molar ratio of 1:1.8 to bisaminopropyl polydimethylsiloxane to obtain a reaction solution F, reacting at a constant temperature of 55° C. for 2 h to obtain a pretreated reaction solution, washing with a saturated sodium chloride solution and vacuum drying to obtain a modified liquid, adding acrylic resin to the mixture to obtain a fluorinated acrylic resin, wherein the mass ratio of bisaminopropyl polydimethylsiloxane to acrylic resin is 1:15; S4: Mix the fluorinated acrylic resin with the curing agent, then add the modified graphene / alumina, resveratrol / montmorillonite, OP-100, perfluoroalkyl ester FC430, and silicone defoamer, stir evenly, and obtain a highly weather-resistant solvent-free coating.

[0076] Example 4

[0077] This embodiment provides a highly weather-resistant solvent-free coating and a preparation method thereof, wherein the highly weather-resistant solvent-free coating comprises the following components in parts by weight: 80 parts of fluorinated acrylic resin; Modified graphene / alumina 15 parts; Resveratrol / montmorillonite 10 parts; 20 parts of curing agent; 5 parts of additives; The auxiliary agents include emulsifier, leveling agent and defoamer, wherein the emulsifier is 3 parts, the leveling agent is 1 part and the defoamer is 1 part.

[0078] The preparation method specifically comprises the following steps: S1: Add graphite and sodium nitrate to sulfuric acid in an ice-water bath. The mass ratio of graphite to sodium nitrate is 1:0.75; the feed ratio of graphite to sulfuric acid is 1g / 45mL, followed by potassium permanganate, the mass ratio of graphite to potassium permanganate is 1:5, to obtain reaction solution A, constant temperature reaction at 88°C for 1.2h to obtain reaction solution B, add hydrogen peroxide, the molar ratio of potassium permanganate to hydrogen peroxide is 1:1.5, after washing and freeze-drying to obtain graphene; add graphene and imidazole to deionized water, wherein the concentration of graphene is 1mg / mL; the mass ratio of graphene to imidazole is 1:7.5, and then add aluminum oxide nanoparticles, the mass ratio of graphene to aluminum oxide is 1:0.78, to obtain reaction solution C, ultrasonic and react to obtain reaction solution D, filter, wash and dry to obtain modified graphene / alumina; S2: adding montmorillonite to a 9.2wt% dimethyldiallyl ammonium chloride solution to obtain a dispersion, wherein the mass ratio of montmorillonite to dimethyldiallyl ammonium chloride is 1:0.75, reacting at 67°C for 1.8h, filtering, washing, and drying to obtain modified montmorillonite; preparing a 3.5wt% resveratrol ethanol solution, adding the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, wherein the mass ratio of resveratrol to the modified montmorillonite is 1:5, stirring to react to obtain a reaction solution E, wherein the stirring reaction speed is 500rpm; the reaction time is 3.2h, centrifuging, washing, and freeze-drying to obtain resveratrol / montmorillonite; S3: adding triethylamine to toluene, the concentration of triethylamine being 2.8 mol / L, adding bisaminopropyl polydimethylsiloxane in a molar ratio of 1:3 to triethylamine and perfluorooctane sulfonyl fluoride in a molar ratio of 1:1 to bisaminopropyl polydimethylsiloxane to obtain a reaction solution F, reacting at a constant temperature of 58° C. for 3.5 h to obtain a pretreated reaction solution, washing with a saturated sodium chloride solution and vacuum drying to obtain a modified liquid, adding acrylic resin to the mixture to obtain a fluorinated acrylic resin, wherein the mass ratio of bisaminopropyl polydimethylsiloxane to acrylic resin is 1:20; S4: The fluorinated acrylic resin and the curing agent are mixed, and then the modified graphene / alumina, resveratrol / montmorillonite, PEG-400, Byk-306, and FoamStar SI 2210 are added and stirred evenly to obtain a highly weather-resistant solvent-free coating.

[0079] Comparative Example 1 This comparative example provides a method for preparing a highly weather-resistant solvent-free coating, which differs from Example 1 in that in step S1, the mass ratio of graphite to potassium permanganate is adjusted to 1:6, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0080] Comparative Example 2 This comparative example provides a method for preparing a highly weather-resistant solvent-free coating, which differs from Example 1 in that in step S1, the mass ratio of graphite to potassium permanganate is adjusted to 1:2, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0081] Comparative Example 3 This comparative example provides a method for preparing a highly weather-resistant solvent-free coating. The difference from Example 1 is that in step S1, the molar ratio of perfluorooctane sulfonyl fluoride to bisaminopropyl polydimethylsiloxane is adjusted to 2:1.5, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0082] Comparative Example 4 This comparative example provides a method for preparing a highly weather-resistant solvent-free coating, which differs from Example 1 in that in step S1, the mass ratio of graphite to potassium permanganate is adjusted to 0.2:1.5, and the other operating steps and process parameters are exactly the same as those in Example 1.

[0083] The performance test of the highly weather-resistant solvent-free coatings of the above-mentioned Examples 1-4 and Comparative Examples 1-4 was carried out, and the specific process is as follows: Test the adhesion of samples according to GB / T 9286-2021; Test the samples for UV aging resistance according to IOS 7724-2; The test results are shown in Table 1.

[0084] Table 1: Test results of high weather resistance solvent-free coating performance of Examples 1-4 and Comparative Examples 1-4

[0085] It can be seen from Table 1 that the highly weather-resistant solvent-free coatings prepared in Examples 1-4 provided by the present invention have good adhesion and weather resistance.

[0086] It can be seen from the test results of Example 1 and Comparative Examples 1 and 2 that when the feeding amount of potassium permanganate is too high, it will lead to excessive oxidation of graphite, and the generated graphene oxide surface contains more carboxyl and hydroxyl groups, which improves the hydrophilicity, but the oxidized functional groups are easy to further react with free radicals or corrosive media, aggravating the degradation process of the coating, and ultimately weakening the weather resistance of the coating; when the feeding amount is too low, it will lead to insufficient oxidation, incomplete exfoliation of graphite layers, thicker graphene sheets, and poorer dispersion, thereby affecting the barrier properties of the coating and reducing its barrier ability to corrosive media.

[0087] From the test results of Example 1 and Comparative Examples 3 and 4, it can be seen that by introducing perfluorooctane sulfonyl fluoride, fluorinated groups can be introduced into the acrylic resin molecular chain, which can effectively absorb or reflect ultraviolet rays, prevent ultraviolet rays from causing photoaging to the coating substrate, and improve the weather resistance of the coating in outdoor environments. When the amount of perfluorooctane sulfonyl fluoride is too much, it may cause the generated fluorinated groups to be unevenly distributed on the resin molecular chain, thereby affecting the performance consistency of the coating surface, making the surface of the coating too hydrophobic, and the self-cleaning performance is too strong, resulting in insufficient adhesion; and when the amount is too little, the fluorinated structure is not introduced enough, resulting in insufficient resistance of the acrylic resin to chemical corrosion and ultraviolet rays, and the weather resistance of the coating is reduced.

[0088] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a highly weather-resistant solvent-free coating, characterized in that: The preparation method comprises: S1: adding graphite and sodium nitrate to sulfuric acid in an ice water bath, then adding potassium permanganate to obtain reaction solution A, reacting at a constant temperature to obtain reaction solution B, adding hydrogen peroxide, washing, and freeze-drying to obtain graphene; adding graphene and imidazole to deionized water, then adding alumina nanoparticles to obtain reaction solution C, ultrasonicating and reacting to obtain reaction solution D, filtering, washing, and drying to obtain modified graphene / alumina; S2: adding montmorillonite to a dimethyldiallyl ammonium chloride solution to obtain a dispersion, filtering, washing, and drying after the reaction to obtain a modified montmorillonite; preparing a resveratrol ethanol solution, adding the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, stirring the mixture to obtain a reaction solution E, centrifuging, washing, and freeze-drying to obtain resveratrol / montmorillonite; S3: adding triethylamine to toluene, adding bisaminopropyl polydimethylsiloxane and perfluorooctane sulfonyl fluoride to obtain a reaction solution F, reacting at a constant temperature to obtain a pre-treated reaction solution, washing with a saturated sodium chloride solution and vacuum drying to obtain a modified liquid, adding acrylic resin to the mixture to obtain a fluorinated acrylic resin; S4: Mix the fluorinated acrylic resin with the curing agent, then add the modified graphene / alumina, resveratrol / montmorillonite, and the additive, stir evenly, and obtain a highly weather-resistant solvent-free coating.

2. The method for preparing a highly weather-resistant solvent-free coating according to claim 1, characterized in that: In S1: The mass ratio of graphite to sodium nitrate is 1:(0.5-1); The feeding ratio of graphite to sulfuric acid is 1g / 35-45mL; The mass ratio of the graphite to potassium permanganate is 1:(4-5).

3. The method for preparing a highly weather-resistant solvent-free coating according to claim 1, characterized in that: In S1: the molar ratio of potassium permanganate to hydrogen peroxide is 1:(1-1.5).

4. The method for preparing a highly weather-resistant solvent-free coating according to claim 1, characterized in that: In S1: The mass ratio of graphene to imidazole is 1:(5-10); The mass ratio of the graphene to the aluminum oxide nanoparticles is 1:(0.5-1).

5. The method for preparing a highly weather-resistant solvent-free coating according to claim 1, characterized in that: In S2: the mass ratio of the montmorillonite to dimethyldiallylammonium chloride is 1:(0.5-1).

6. The method for preparing a highly weather-resistant solvent-free coating according to claim 1, characterized in that: In S2: the mass ratio of the resveratrol to the modified montmorillonite is 1:(1-5).

7. The method for preparing a highly weather-resistant solvent-free coating according to claim 1, characterized in that: In S3: The molar ratio of the bisaminopropyl polydimethylsiloxane to triethylamine is 1:(1-3); The molar ratio of perfluorooctane sulfonyl fluoride to bisaminopropyl polydimethylsiloxane is 1:(1-2).

8. The method for preparing a highly weather-resistant solvent-free coating according to claim 1, characterized in that: In S3: the mass ratio of the bisaminopropyl polydimethylsiloxane to the acrylic resin is 1:(10-20).

9. The method for preparing a highly weather-resistant solvent-free coating according to claim 1, characterized in that: In S4: The curing agent is hexamethylene diisocyanate trimer or isophorone diisocyanate trimer; The auxiliary agents include emulsifiers, leveling agents and defoamers; The emulsifier is OP-100 or PEG-400; The leveling agent is Byk-306 or perfluoroalkyl ester FC430; The defoamer is silicone defoamer or FoamStar SI 2210.

10. A highly weather-resistant solvent-free coating prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The highly weather-resistant solvent-free coating comprises the following components in parts by mass: 50-80 parts of fluorinated acrylic resin; Modified graphene / aluminum oxide 5-15 parts; Resveratrol / montmorillonite 3-10 parts; 10-20 parts of curing agent; 2.2-5 parts of additives; The auxiliary agents include emulsifier, leveling agent and defoamer, wherein the emulsifier is 2-4 parts, the leveling agent is 0.1-0.5 parts and the defoamer is 0.1-0.5 parts.

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