A high weather-resistant solvent-free coating and its preparation method

Abstract

The present invention provides a high weather-resistant solvent-free coating and a preparation method thereof, belonging to the technical field of coatings. In the present invention, a modified graphene / aluminum oxide composite material is introduced to construct a complex three-dimensional crosslinked structure, enhancing the physical barrier effect of the coating and extending the penetration path of corrosive media, thereby improving the weather resistance. The synergistic modification of resveratrol / montmorillonite further optimizes the barrier performance of the coating, in which montmorillonite and graphene act together to form a dense barrier layer, and resveratrol effectively inhibits the oxidative degradation of the acrylic matrix by scavenging free radicals, extending the service life of the coating. In addition, fluorinated groups and organosilicon groups are introduced into the acrylic resin chain, where the fluorinated groups endow the coating with excellent weather resistance, and the organosilicon groups provide an additional barrier through a flexible network structure to further block the intrusion of corrosive media. This multiple protection mechanism significantly improves the durability and protection performance of the coating, meeting the usage requirements in harsh environments.

Description

Technical Field

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

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

[0003] Solvent-free coatings, because they contain no or only extremely small amounts of organic volatile compounds, greatly reduce environmental pollution and comply with the increasingly strict global environmental protection regulations. At the same time, their low odor, rapid curing, and excellent coating properties during construction make them an ideal choice widely used in industrial and architectural coatings. Such coatings not only exhibit excellent mechanical properties and chemical stability, but also have outstanding performances in anti-corrosion, anti-aging, and long-term weather resistance, so they are widely used in the protective coatings of industrial equipment, decorative coatings for building exterior walls, and anti-corrosion coatings in marine environments and other fields.

[0004] Acrylic resins have become an indispensable substrate in modern coating systems due to their excellent comprehensive properties. Their outstanding gloss retention ability and flexible molecular structure design make them occupy an important position in architectural coatings and industrial coatings. However, traditional acrylic resin coatings also face challenges in applications: in an environment with high ultraviolet radiation, they are prone to photoaging, resulting in surface cracking and gloss decline. This problem severely limits the performance of traditional acrylic resin coatings in harsh application scenarios. Summary of the Invention

[0005] In view of the above problems, the object of the present invention is to provide a high weather-resistant solvent-free coating and a preparation method thereof. By compounding and modifying graphene with alumina nanoparticles, the barrier performance of the coating is improved, and excellent mechanical strength and chemical corrosion resistance are imparted to the coating; after the introduced montmorillonite is cation-modified, the complex formed with resveratrol further enhances the anti-ultraviolet aging and anti-oxidation performance of the coating; perfluorooctanesulfonyl fluoride reacts with diaminopropyl polydimethylsiloxane to generate a fluorinated organosilicon compound, which is introduced into the acrylic resin, forming a large number of low surface energy fluorinated structures on the resin chain, and at the same time enhancing the flexibility and adhesion performance of the coating film through the flexible network of organosilicon groups. The introduction of fluorinated groups also significantly improves the hydrophobicity, chemical corrosion resistance and anti-pollution performance of the coating, making it exhibit excellent weather resistance in harsh environments.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a preparation method of a high weather-resistant solvent-free coating, and the preparation method of the high weather-resistant solvent-free coating includes:

[0008] S1: Add graphite and sodium nitrate to sulfuric acid under an ice-water bath, then add potassium permanganate to obtain reaction solution A. After constant temperature reaction, obtain reaction solution B, add hydrogen peroxide, and obtain graphene after washing and freeze-drying; add graphene and imidazole to deionized water, then add alumina nanoparticles to obtain reaction solution C, and obtain reaction solution D after ultrasonic treatment and reaction, and obtain modified graphene / alumina after filtration, washing and drying;

[0009] S2: Add montmorillonite to a dimethyldiallylammonium chloride solution to obtain a dispersion liquid, and obtain modified montmorillonite after reaction, filtration, washing and drying; prepare a resveratrol ethanol solution, add the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, and obtain reaction solution E after stirring reaction, and obtain resveratrol / montmorillonite after centrifugation, washing and freeze-drying;

[0010] S3: Add triethylamine to toluene, add diaminopropyl polydimethylsiloxane and perfluorooctanesulfonyl fluoride to obtain reaction solution F, obtain a pretreated reaction solution after constant temperature reaction, wash with saturated sodium chloride solution and then vacuum dry to obtain a modified liquid, and add it to an acrylic resin to mix to obtain a fluorinated acrylic resin;

[0011] S4: Mix the fluorinated acrylic resin with a curing agent, then add the modified graphene / alumina, resveratrol / montmorillonite, and additives, and stir evenly to obtain a high weather-resistant solvent-free coating.

[0012] As a preferred technical solution of the present invention, in step S1, the mass ratio of the graphite to the 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 this numerical range are equally applicable.

[0013] In some alternative examples, the feeding ratio of the graphite to the sulfuric acid is 1 g / 35 - 45 mL, for example, it can be 1 g:35 mL, 1 g:36 mL, 1 g:37 mL, 1 g:38 mL, 1 g:39 mL, 1 g:40 mL, 1 g:41 mL, 1 g:42 mL, 1 g:43 mL, 1 g:44 mL or 1 g:45 mL, but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0014] In some alternative examples, the mass ratio of the graphite to the 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 this numerical range are equally applicable.

[0015] In some alternative examples, the temperature for the constant-temperature reaction of the reaction solution 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 this numerical range are equally applicable.

[0016] In some alternative examples, the time for the constant-temperature reaction of the reaction solution A is 1 - 2 h, for example, it can be 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 this numerical range are equally applicable.

[0017] In some alternative examples, the molar ratio of the potassium permanganate to the 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 this numerical range are equally applicable.

[0018] In some alternative examples, the concentration of the 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0019] In some alternative examples, the mass ratio of the 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0020] In some alternative examples, the mass ratio of the graphene to alumina 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0021] As a preferred technical solution of the present invention, in step S2, the mass ratio of the 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0022] In some alternative examples, the mass fraction of the dimethyldiallylammonium chloride solution is 5 - 10 wt.%. For example, it can be 5.0 wt.%, 5.5 wt.%, 6.0 wt.%, 6.5 wt.%, 7.0 wt.%, 7.5 wt.%, 8.0 wt.%, 8.5 wt.%, 9.0 wt.%, 9.5 wt.% or 10.0 wt.%. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0023] In some alternative examples, the temperature of the dispersion reaction is 60 - 70 °C. For example, it can be 60 °C, 61 °C, 62 °C, 63 °C, 64 °C, 65 °C, 66 °C, 67 °C, 68 °C, 69 °C or 70 °C. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0024] In some alternative examples, the reaction time of the dispersion is 1 - 2 h. For example, it can be 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. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0025] In some alternative examples, the mass fraction of the resveratrol ethanol solution is 1 - 5 wt.%. For example, it can be 1.0 wt.%, 1.5 wt.%, 2.0 wt.%, 2.5 wt.%, 3.0 wt.%, 3.5 wt.%, 4.0 wt.%, 4.5 wt.% or 5.0 wt.%. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0026] In some alternative 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. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0027] In some alternative examples, the rotation speed of the composite solution during the stirring reaction is 500 - 600 rpm. For example, it can be 500 rpm, 510 rpm, 520 rpm, 530 rpm, 540 rpm, 550 rpm, 560 rpm, 570 rpm, 580 rpm, 590 rpm or 600 rpm. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0028] In some alternative examples, the reaction time of the composite solution during the stirring reaction is 2 - 4 h. For example, it can be 2.0 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h, 3.0 h, 3.2 h, 3.4 h, 3.6 h, 3.8 h or 4.0 h. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0029] 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0030] In some alternative examples, the molar ratio of diaminopropyl 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0031] In some alternative examples, the molar ratio of perfluorooctane sulfonyl fluoride to diaminopropyl 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0032] In some alternative examples, the temperature for the constant-temperature reaction of reaction solution 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0033] In some alternative examples, the time for the constant-temperature reaction of reaction solution F is 2 - 4 h. For example, it can be 2.0 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h, 3.0 h, 3.2 h, 3.4 h, 3.6 h, 3.8 h or 4.0 h. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0034] In some alternative examples, the mass ratio of diaminopropyl polydimethylsiloxane to 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0035] In some alternative examples, the curing agent is hexamethylene diisocyanate trimer or isophorone diisocyanate trimer;

[0036] The auxiliaries include an emulsifier, a leveling agent and an antifoaming agent; wherein the emulsifier is OP-100 or PEG-400;

[0037] The leveling agent is Byk-306 or perfluoroalkyl ester FC430; the antifoaming agent is a silicone antifoaming agent or FoamStar SI2210.

[0038] In a second aspect, the present invention provides a high weather resistance solvent-free coating, and the high weather resistance solvent-free coating comprises the following components in parts by mass:

[0039] Fluorinated acrylic resin 50 - 80 parts;

[0040] Modified graphene / aluminum oxide 5 - 15 parts;

[0041] Resveratrol / montmorillonite 3 - 10 parts;

[0042] Curing agent 10 - 20 parts;

[0043] Auxiliaries 2 - 5 parts;

[0044] Wherein the auxiliaries include an emulsifier, a leveling agent and an antifoaming agent, the emulsifier is 1 - 3 parts; the leveling agent is 0.5 - 1 part; the antifoaming agent is 0.5 - 1 part.

[0045] In some alternative examples, the mass fraction 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 is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0046] In some alternative examples, the mass fraction of the 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 this value range are equally applicable.

[0047] In some alternative examples, the mass parts of resveratrol / montmorillonite are 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0048] In some alternative examples, the mass parts of the curing agent are 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0049] In some alternative examples, the mass parts of the auxiliary agent are 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0050] In some alternative examples, the mass parts of the emulsifier are 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0051] In some alternative examples, the mass parts of the leveling agent are 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0052] In some alternative examples, the mass parts of the defoamer are 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0053] The present invention introduces graphene to modify acrylic resin. Graphene has a unique two-dimensional layered structure and a wide π-π conjugated system, which has excellent absorption and shielding effects on ultraviolet light, can effectively reduce the damage of ultraviolet light to the acrylic resin matrix, thus inhibiting the photo-degradation phenomenon caused by ultraviolet light, improving the anti-aging performance 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 corrosive factors such as oxides on the coating, and keep the coating stable in complex environments.

[0054] The lamellar 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 especially suitable for application scenarios with extremely high requirements for corrosion resistance, such as coatings for marine equipment and chemical pipelines. The high thermal conductivity of graphene can also disperse the heat on the coating surface, reduce the performance deterioration caused by heat, and make the coating show better stability in high-temperature environments.

[0055] At the same time, graphene is an excellent reinforcing filler in the coating. Through the interaction between its lamellae and the strong interfacial action, it endows the coating with higher mechanical strength, wear resistance and impact resistance, so that it can maintain excellent performance for a long time under harsh conditions in the fields of heavy industry, transportation, etc.

[0056] The present invention combines alumina with graphene to give full play to the synergistic effect of the two in the coating system. The alumina particles are combined with the graphene lamellae to form a complex three-dimensional cross-linked structure, making the physical barrier inside the coating more dense. This structure can significantly extend the penetration path of corrosive media (such as moisture, oxygen and ions), greatly improve the barrier performance of the coating, and thus enhance the anti-corrosion effect of the coating, which is especially suitable for long-term protection requirements in harsh environments.

[0057] At the same time, due to the strong van der Waals force and large specific surface area of graphene in the coating, agglomeration is likely to occur, which will affect 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, and ensuring the consistency and stability of the coating performance. The surface of alumina has abundant hydroxyl groups, which can further improve its compatibility with the acrylic resin matrix through chemical modification, thus 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 meet the requirements of different coating processes.

[0058] Aluminum oxide, as an inorganic material, has excellent thermal stability. Its combination with graphene can further enhance the tolerance of the coating under high-temperature conditions. For example, when the coating is exposed to high temperature or thermal shock environments, the composite material can reduce thermal degradation and performance decline, maintaining the physical and chemical integrity of the coating. At the same time, the high thermal conductivity of aluminum oxide combined with the excellent thermal conductivity of graphene can improve the heat dissipation capacity of the coating, reduce the surface temperature of the substrate, and thus play a role in heat insulation and protection. This enables the coating to exhibit more excellent stability and protection effects in high-temperature environments.

[0059] In this invention, montmorillonite is introduced to modify the acrylic resin. The lamellar structure of montmorillonite can be evenly dispersed in the coating matrix, forming a nano-reinforcement effect, thereby greatly enhancing the mechanical properties of the coating. Due to the high rigidity and strong interfacial force of the lamellae, it can effectively prevent the coating from cracking or breaking when subjected to external mechanical stress, enabling the coating to exhibit better tolerance in terms of impact resistance and tensile resistance. In addition, the lamellar structure can also absorb and disperse the external impact energy, reducing local stress concentration, and thus significantly reducing the risk of coating damage.

[0060] The lamellar structure of montmorillonite can also significantly extend the penetration path of corrosive media (such as moisture, oxygen, and ions) through the "labyrinth effect". The high lateral specific surface area and arrangement of the lamellae form a series of complex physical barriers in the coating, forcing the corrosive media to diffuse "zigzag" 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.

[0061] 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 enables the coating to exhibit higher thermal degradation resistance in high-temperature environments, reducing performance decline caused by temperature fluctuations. In addition, the lamellar structure can also shield the damaging effect of ultraviolet rays on the coating, thereby improving the anti-aging performance of the coating and enabling it to exhibit a more durable protection effect during long-term outdoor use.

[0062] Dimethyldiallylammonium chloride is used to modify montmorillonite. Through this modification process, the disadvantages that montmorillonite originally has strong hydrophilicity and is difficult to be well compatible with organic systems such as acrylic resin are overcome. Dimethyldiallylammonium chloride, as a cationic quaternary ammonium salt, can embed its cations into the interlayer structure of montmorillonite through cation exchange reactions between the cations and the interlayer of montmorillonite, thereby realizing the transformation of montmorillonite from hydrophilic to hydrophobic or organophilic. The modified montmorillonite exhibits better organophilicity, and its compatibility with the acrylic resin matrix is significantly enhanced, which helps to improve the overall mechanical properties and adhesion of the coating.

[0063] In addition, the quaternary ammonium salt structure introduced during the modification of dimethyldiallylammonium chloride also endows montmorillonite with certain antistatic properties. In coatings, this characteristic helps to reduce the electrostatic deposition effect on the coating surface, thereby reducing the adsorption of particulate matters such as dust and pollutants. This not only improves the surface smoothness of the coating, but also enhances the decorative effect and cleaning performance of the coating, which is very suitable for coating application scenarios with high appearance requirements.

[0064] At the same time, for the modified montmorillonite, its layer spacing is significantly increased, and the originally closely packed lamellar structure is effectively separated. This makes the dispersion of montmorillonite in the coating more uniform, avoiding the phenomenon of local performance deterioration caused by lamellar aggregation. The uniformly dispersed montmorillonite lamellae can form a more continuous "labyrinth effect" barrier in the coating, thereby further extending the penetration path of corrosive media and improving the corrosion resistance and barrier performance of the coating.

[0065] Resveratrol is used in combination with montmorillonite. Resveratrol is a natural polyphenolic compound containing phenolic hydroxyl groups in its molecule and has strong antioxidant activity. By introducing resveratrol into the interlayer structure or surface of montmorillonite, free radicals can be effectively captured, the oxidative degradation of the acrylic matrix can be reduced, and the service life of the coating can be extended; at the same time, resveratrol has natural antibacterial activity and can inhibit the spread of bacterial colonies by interfering with microbial metabolism and inhibiting their growth and reproduction. After combining with montmorillonite, the resulting 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 the appearance of mildew or biological corrosion on the coating surface, and improve the applicability and durability of the coating.

[0066] There is also a synergistic effect between montmorillonite and graphene: both montmorillonite and graphene have lamellar structures, but they have their own advantages in characteristics and functions. The lamellae of graphene are denser, with excellent barrier properties and mechanical strength, while the montmorillonite lamellae have a larger specific surface area and good physical barrier characteristics. Combining montmorillonite with graphene can achieve complementary advantages: montmorillonite fills the gaps between the graphene lamellae, effectively improving the barrier performance 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 enhancing the anti-corrosion performance and long-term weather resistance of the coating.

[0067] In terms of mechanical properties, the combination of montmorillonite and graphene also exhibits significant complementary advantages. Montmorillonite provides macroscopic structural support, which can increase the rigidity and dimensional stability of the coating, while graphene enhances the micro-mechanical properties of the composite coating, such as tensile strength, toughness, and wear resistance. The combined action of the two enables the composite coating to achieve a balance between strength and toughness, not only resisting external impacts but also effectively preventing coating cracking and peeling, and prolonging the service life of the coating.

[0068] Due to the strong van der Waals forces between the graphene sheets, graphene is prone to agglomeration, thus reducing its dispersibility and uniformity in the coating. However, through combination with montmorillonite, this problem has been significantly improved. The intercalation effect of montmorillonite can effectively reduce the stacking of graphene sheets, making their distribution more uniform, thereby improving the dispersibility and stability of the composite material. In addition, through surface modification of montmorillonite (such as organic treatment or graft modification), its compatibility with the acrylic resin matrix can be enhanced. The intercalated structure of the modified montmorillonite provides additional support for graphene and simultaneously forms a good interfacial bond, improving the dispersion effect of graphene in the matrix and significantly enhancing the adhesion of the coating.

[0069] This synergistic effect not only improves the barrier and mechanical properties of the coating but also endows the coating with more functions. For example, the electrical conductivity of graphene can endow the coating with certain antistatic properties, while the high thermal stability of montmorillonite enhances the high-temperature resistance of the coating. The composite coating formed by their combination exhibits comprehensive advantages in aspects such as anti-corrosion, wear resistance, high-temperature resistance, and anti-aging, making it have broad application prospects in the fields of industrial coatings, protective coatings, and functional coatings.

[0070] In this invention, the acrylic resin is modified by introducing fluorinated groups. Perfluorooctanesulfonyl fluoride is used as a fluorination reagent to react with diaminopropyl polydimethylsiloxane to generate a fluorinated organosilicon compound, which contains both fluorinated groups and organosilicon groups in its molecular structure. Subsequently, this compound combines with the acrylic resin, introducing a large number of fluorine atoms onto the acrylic resin chain. The introduction of fluorine atoms forms a fluorinated structure with an extremely low surface energy, significantly enhancing the hydrophobicity, oleophobicity, and anti-pollution performance of the resin, enabling the coating to effectively prevent the adhesion of moisture, oil, and dust, and at the same time greatly improving the cleaning convenience and stain resistance.

[0071] In addition, fluorinated groups have excellent chemical inertness and high weather resistance, greatly enhancing the resistance to chemical corrosion and ultraviolet rays. This modification enables the coating to perform excellently in harsh environments, such as resisting aging or yellowing caused by acid-base 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 requiring high durability and aesthetics.

[0072] The introduction of diaminopropyl 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 enhances the toughness of the resin, making the coating film more elastic and crack-resistant when dealing with external force impacts 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 phenomena, and endows the acrylic resin with better flexibility and surface adjustment performance.

[0073] There is also a synergistic effect between the simultaneously introduced silicone groups and fluorinated groups: the fluorinated groups reduce the surface energy of the coating surface, endowing the coating film with self-cleaning properties. This extremely low surface energy can effectively prevent the adhesion of dust, water stains, and oil stains, enabling the coating to maintain a long-term clean state in various application scenarios and reducing maintenance costs. The silicone groups further enhance the lubricity and surface smoothness of the coating film, making the coating surface more flat and uniform, not only improving the visual and tactile texture but also making cleaning and maintenance more convenient.

[0074] Secondly, the fluorinated acrylic resin exhibits extremely high chemical inertness to water, acids, alkalis, and salt solutions. This property enables the coating to maintain stability in corrosive environments for a long time, avoiding aging, peeling, or failure caused by chemical corrosion. 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.

[0075] At the same time, the synergistic effect of the silicone groups and fluorinated groups significantly improves the interfacial compatibility of the resin with inorganic materials (such as modified graphene / aluminum oxide, resveratrol / montmorillonite) by reducing the polarity of the acrylic resin. In the composite coating system, the modified resin can coat the inorganic fillers more uniformly, forming a stable dispersion system, avoiding the agglomeration of inorganic materials, and further improving the mechanical properties and functional stability of the composite coating.

[0076] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0077] (1) The introduction of the modified graphene / aluminum oxide composite material forms a complex three-dimensional cross-linked structure, making the physical shielding inside the coating more dense, extending the penetration path of the corrosive medium, and thus enhancing the weather resistance of the coating;

[0078] (2) The introduction of resveratrol / montmorillonite to modify the acrylic resin: montmorillonite and graphene act synergistically to effectively improve the barrier performance 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;

[0079] (3) By introducing fluorinated groups and silicone groups onto the acrylic resin chain, the high weather resistance of the fluorinated groups enables the coating to perform better in harsh environments. 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 protection effect of the coating. This dual protection mechanism improves the durability of the coating. Description of the Drawings

[0080] Figure 1 It is a flowchart of the preparation method of the high weather resistance solvent-free coating provided in Example 1 of the present invention;

[0081] Figure 2 It is the infrared spectrum of graphene and imidazole-modified graphene provided in Example 1 of the present invention. Specific Embodiments

[0082] The technical solutions of the present invention will be described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments described herein are specific specific embodiments of the present invention and are used to illustrate the concept of the present invention; these descriptions are all explanatory and exemplary, and should not be construed as limiting the embodiments of the present invention and the protection scope of the present invention. Except for the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of the present application. These technical solutions include technical solutions that make any obvious substitutions and modifications to the embodiments described herein.

[0083] The chemical reagents used in the embodiments and comparative examples of the present invention are all commercially available products, and their brand names, specifications, manufacturers and other information are as follows:

[0084] Graphite: Purchased from Wulanchabu Dasheng Graphite New Materials Co., Ltd.;

[0085] Sodium nitrate: Purity ≥ 99%, purchased from Shandong Xinhao Chemical Co., Ltd.;

[0086] Sulfuric acid: Purity ≥ 99%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0087] Potassium permanganate: Purity ≥ 99%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0088] Hydrogen peroxide: Purity ≥ 30%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0089] Imidazole: Purity ≥ 99%, purchased from Jiangsu Kanglejia Materials Co., Ltd.;

[0090] Alumina nanoparticles: Particle size 30 - 50nm, purchased from Suzhou Baird New Materials Technology Co., Ltd.;

[0091] Montmorillonite: purchased from Sinopharm Chemical Reagent Co., Ltd.

[0092] Dimethyldiallylammonium chloride: purity 65±1%, purchased from Zhejiang Xinhaitian Biotechnology Co., Ltd.;

[0093] Resveratrol: purity ≥98%, purchased from Dongming Grus Biotechnology Co., Ltd.;

[0094] Anhydrous ethanol: purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0095] Triethylamine: purity ≥99%, purchased from Shandong Liding Chemical Technology Co., Ltd.;

[0096] Toluene: purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0097] Bisaminopropyl polydimethylsiloxane: MW = 1000, purchased from Beijing Bailingwei Technology Co., Ltd.;

[0098] Perfluorooctane sulfonyl fluoride: purity ≥90%, purchased from Wuhan Haide Chemical Development Co., Ltd.;

[0099] Sodium chloride: purity ≥99%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0100] Acrylic resin: purchased from Guangdong Kelisen Resin Co., Ltd.;

[0101] Hexamethylene diisocyanate trimer: purchased from Zichuan Biochemical Technology (Suzhou) Co., Ltd.;

[0102] Isophorone diisocyanate trimer: purity ≥99%, purchased from Wanhua Chemical Group Co., Ltd.;

[0103] OP-100: purity ≥99%, purchased from Zibo Haijie Chemical Co., Ltd.;

[0104] PEG-400: purchased from Jiangsu Dena Chemical Co., Ltd.;

[0105] Byk-306: purchased from Dongyang Chemical (Hong Kong) Co., Ltd.;

[0106] Perfluoroalkyl ester FC430: purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.;

[0107] Silicone defoamer: purchased from Guangdong Nanhui New Materials Co., Ltd.

[0108] FoamStar SI 2210: purchased from BASF SE;

[0109] Example 1

[0110] like Figure 1As shown in the figure, this embodiment provides a high weather-resistant solvent-free coating and a preparation method thereof. Among them, the high weather-resistant solvent-free coating comprises the following components in parts by mass:

[0111] 65 parts of fluorinated acrylic resin;

[0112] 10 parts of modified graphene / aluminum oxide;

[0113] 7 parts of resveratrol / montmorillonite;

[0114] 15 parts of curing agent;

[0115] 3.35 parts of additives;

[0116] Among them, the additives include emulsifier, leveling agent and defoamer. The emulsifier is 2 parts; the leveling agent is 0.7 parts; the defoamer is 0.85 parts.

[0117] The specific preparation method comprises the following steps:

[0118] S1: Add graphite and sodium nitrate to sulfuric acid under an ice-water bath. The mass ratio of graphite to sodium nitrate is 1:1; the feeding ratio of graphite to sulfuric acid is 1 g / 35 mL. Then add potassium permanganate, and the mass ratio of graphite to potassium permanganate is 1:4 to obtain reaction solution A. After reacting at a constant temperature of 80 °C for 2 h, reaction solution B is obtained. Add hydrogen peroxide, and the molar ratio of potassium permanganate to hydrogen peroxide is 1:1. After washing and freeze-drying, graphene is obtained. Add graphene and imidazole to deionized water. Among them, the concentration of graphene is 0.8 mg / mL; the mass ratio of graphene to imidazole is 1:8. Then add alumina nanoparticles, and the mass ratio of graphene to alumina is 1:1 to obtain reaction solution C. After ultrasonic treatment and reaction, reaction solution D is obtained. After filtration, washing and drying, modified graphene / aluminum oxide is obtained. The infrared spectra of graphene and imidazole-modified graphene are as Figure 2 shown: In the infrared spectrum of graphene, 3450 cm -1 corresponds to the stretching vibration of -OH; 1650 cm -1 corresponds to the stretching vibration of C=O; the peak at 1085 cm -1 corresponds to the stretching vibration of C-O. In the infrared spectrum of imidazole-modified graphene, the stretching vibration of C-N is at 1500 cm -1 , and the signal peak of N-H is at 1069 cm -1 , which indicates that covalent reaction occurs between imidazole and graphene.

[0119] S2: Add montmorillonite into a dimethyldiallylammonium chloride solution with a mass fraction of 8 wt.%, where the mass ratio of montmorillonite to dimethyldiallylammonium chloride is 1:0.8. React at 65 °C for 2 h, then filter, wash, and dry to obtain modified montmorillonite. Prepare a resveratrol ethanol solution with a mass fraction of 4 wt.%, and add the modified montmorillonite into the resveratrol ethanol solution to obtain a composite solution, where the mass ratio of resveratrol to modified montmorillonite is 1:3.8. Stir and react to obtain reaction solution E, where the stirring speed is 570 rpm and the time is 3 h. Centrifuge, wash, and freeze-dry to obtain resveratrol / montmorillonite;

[0120] S3: Add triethylamine into toluene, with the concentration of triethylamine being 2.5 mol / L. Add bis(3-aminopropyl)polydimethylsiloxane with a molar ratio of 1:2 to triethylamine and perfluorooctanesulfonyl fluoride with a molar ratio of 1:1.5 to bis(3-aminopropyl)polydimethylsiloxane to obtain reaction solution F. React at a constant temperature of 50 °C for 3 h to obtain a pretreated reaction solution. Wash with saturated sodium chloride solution and then vacuum dry to obtain a modified liquid. Add acrylic resin and mix to obtain fluorinated acrylic resin, where the mass ratio of bis(3-aminopropyl)polydimethylsiloxane to acrylic resin is 1:10;

[0121] S4: Mix the fluorinated acrylic resin with a curing agent, and then add modified graphene / aluminum oxide, resveratrol / montmorillonite, OP-100, Byk-306, and silicone defoamer, and stir evenly to obtain a high weather resistance solvent-free coating.

[0122] Example 2

[0123] This example provides a high weather resistance solvent-free coating and its preparation method. Among them, the high weather resistance solvent-free coating includes the following components in parts by mass:

[0124] Fluorinated acrylic resin: 50 parts;

[0125] Modified graphene / aluminum oxide: 5 parts;

[0126] Resveratrol / montmorillonite: 8.5 parts;

[0127] Curing agent: 18 parts;

[0128] Auxiliary agent: 4 parts;

[0129] Among them, the auxiliary agent includes an emulsifier, a leveling agent, and a defoamer. The emulsifier is 2.4 parts; the leveling agent is 0.85 parts; the defoamer is 0.75 parts.

[0130] The specific preparation method includes the following steps:

[0131] S1: Add graphite and sodium nitrate to sulfuric acid under an ice-water bath. The mass ratio of graphite to sodium nitrate is 1:0.5; the feeding ratio of graphite to sulfuric acid is 1 g / 40 mL. Subsequently, add potassium permanganate, and the mass ratio of graphite to potassium permanganate is 1:4.2 to obtain reaction solution A. After reacting at a constant temperature of 90 °C for 1 h, obtain reaction solution B. Add hydrogen peroxide, and the molar ratio of potassium permanganate to hydrogen peroxide is 1:1.2. After washing and freeze-drying, graphene is obtained; Add graphene and imidazole to deionized water, where the concentration of graphene is 0.5 mg / mL; the mass ratio of graphene to imidazole is 1:5, and then add alumina nanoparticles, and the mass ratio of graphene to alumina is 1:0.5 to obtain reaction solution C. After ultrasonic treatment and reaction, obtain reaction solution D. Filter, wash, and dry to obtain modified graphene / alumina;

[0132] S2: Add montmorillonite to a 10 wt.% dimethyldiallylammonium chloride solution to obtain a dispersion, where the mass ratio of montmorillonite to dimethyldiallylammonium chloride is 1:0.5. After reacting at 70 °C for 1 h, filter, wash, and dry to obtain modified montmorillonite; Prepare a 1 wt.% resveratrol ethanol solution, and add the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, where the mass ratio of resveratrol to the modified montmorillonite is 1:3. Stir and react to obtain reaction solution E, where the stirring speed of the stirring reaction is 550 rpm; the time is 2 h. Centrifuge, wash, and freeze-dry to obtain resveratrol / montmorillonite;

[0133] S3: Add triethylamine to toluene, the concentration of triethylamine is 3 mol / L. Add diaminopropyl polydimethylsiloxane with a molar ratio of 1:1 to triethylamine and perfluorooctanesulfonyl fluoride with a molar ratio of 1:2 to diaminopropyl polydimethylsiloxane to obtain reaction solution F. React at a constant temperature of 60 °C for 4 h to obtain a pretreated reaction solution. Wash with saturated sodium chloride solution and then vacuum dry to obtain a modified liquid. Add acrylic resin and mix to obtain a fluorinated acrylic resin, where the mass ratio of diaminopropyl polydimethylsiloxane to acrylic resin is 1:18;

[0134] S4: Mix the fluorinated acrylic resin with a curing agent, and then add modified graphene / alumina, resveratrol / montmorillonite, PEG-400, perfluoroalkyl ester FC430, and FoamStar SI 2210, and stir evenly to obtain a high weather resistance solvent-free coating.

[0135] Example 3

[0136] This example provides a high weather resistance solvent-free coating and its preparation method. Among them, the high weather resistance solvent-free coating includes the following components in parts by mass:

[0137] 75 parts of fluorinated acrylic resin;

[0138] 12 parts of modified graphene / aluminum oxide;

[0139] 3 parts of resveratrol / montmorillonite;

[0140] 10 parts of curing agent;

[0141] 2 parts of additives;

[0142] Wherein the additives include an emulsifier, a leveling agent and an antifoaming agent, 1 part of emulsifier; 0.5 part of leveling agent; 0.5 part of antifoaming agent.

[0143] The preparation method specifically includes the following steps:

[0144] S1: Add graphite and sodium nitrate to sulfuric acid under an ice-water bath. The mass ratio of graphite to sodium nitrate is 1:0.8; the feeding ratio of graphite to sulfuric acid is 1 g / 42 mL. Subsequently, add potassium permanganate, and the mass ratio of graphite to potassium permanganate is 1:4.5 to obtain reaction solution A. After reacting at a constant temperature of 85°C for 1.5 h, obtain reaction solution B. Add hydrogen peroxide, and the molar ratio of potassium permanganate to hydrogen peroxide is 1:1.4. After washing and freeze-drying, obtain graphene; add graphene and imidazole to deionized water, wherein the concentration of graphene is 0.89 mg / mL; the mass ratio of graphene to imidazole is 1:10, and then add alumina nanoparticles, and the mass ratio of graphene to alumina is 1:0.82 to obtain reaction solution C. After ultrasonic treatment and reaction, obtain reaction solution D. Filter, wash and dry to obtain modified graphene / aluminum oxide;

[0145] S2: Add montmorillonite to a 5 wt.% dimethyldiallylammonium chloride solution to obtain a dispersion, wherein the mass ratio of montmorillonite to dimethyldiallylammonium chloride is 1:1. React at 60°C for 1.5 h, then filter, wash and dry to obtain modified montmorillonite; prepare a 5 wt.% resveratrol ethanol solution, and add 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. Stir and react to obtain reaction solution E, wherein the stirring speed is 600 rpm; the time is 4 h. Centrifuge, wash and freeze-dry to obtain resveratrol / montmorillonite;

[0146] S3: Add triethylamine to toluene, the concentration of triethylamine is 2 mol / L. Add 3-aminopropyl(dimethyl)siloxane with a molar ratio of 1:2.4 to triethylamine and perfluorooctanesulfonyl fluoride with a molar ratio of 1:1.8 to 3-aminopropyl(dimethyl)siloxane to obtain reaction solution F. React at a constant temperature of 55°C for 2 h to obtain a pretreated reaction solution. Wash with saturated sodium chloride solution and then vacuum dry to obtain a modified liquid. Add acrylic resin and mix to obtain fluorinated acrylic resin, wherein the mass ratio of 3-aminopropyl(dimethyl)siloxane to acrylic resin is 1:15;

[0147] S4: Mix the fluorinated acrylic resin with the curing agent, then add modified graphene / aluminum oxide, resveratrol / montmorillonite, OP-100, perfluoroalkyl ester FC430, and silicone defoamer, and stir evenly to obtain a high weather resistance solvent-free coating.

[0148] Example 4

[0149] This example provides a high weather resistance solvent-free coating and its preparation method. Among them, the high weather resistance solvent-free coating includes the following components in parts by mass:

[0150] Fluorinated acrylic resin: 80 parts;

[0151] Modified graphene / aluminum oxide: 15 parts;

[0152] Resveratrol / montmorillonite: 10 parts;

[0153] Curing agent: 20 parts;

[0154] Auxiliary agent: 5 parts;

[0155] Among them, the auxiliary agent includes an emulsifier, a leveling agent, and a defoamer. The emulsifier is 3 parts; the leveling agent is 1 part; the defoamer is 1 part.

[0156] The specific preparation method includes the following steps:

[0157] S1: Add graphite and sodium nitrate to sulfuric acid under an ice-water bath. The mass ratio of graphite to sodium nitrate is 1:0.75; the feeding ratio of graphite to sulfuric acid is 1 g / 45 mL. Then add potassium permanganate, and the mass ratio of graphite to potassium permanganate is 1:5 to obtain reaction solution A. After reacting at a constant temperature of 88 °C for 1.2 h, obtain reaction solution B. Add hydrogen peroxide, and the molar ratio of potassium permanganate to hydrogen peroxide is 1:1.5. After washing and freeze-drying, obtain graphene. Add graphene and imidazole to deionized water, where the concentration of graphene is 1 mg / mL; the mass ratio of graphene to imidazole is 1:7.5. Then add alumina nanoparticles, and the mass ratio of graphene to alumina is 1:0.78 to obtain reaction solution C. After ultrasonic treatment and reaction, obtain reaction solution D. Filter, wash, and dry to obtain modified graphene / aluminum oxide;

[0158] S2: Add montmorillonite to a dimethyldiallylammonium chloride solution with a mass fraction of 9.2 wt.%, where the mass ratio of montmorillonite to dimethyldiallylammonium chloride is 1:0.75. React at 67 °C for 1.8 h, then filter, wash, and dry to obtain modified montmorillonite. Prepare a resveratrol ethanol solution with a mass fraction of 3.5 wt.%, and add the modified montmorillonite to the resveratrol ethanol solution to obtain a composite solution, where the mass ratio of resveratrol to modified montmorillonite is 1:5. Stir to react to obtain reaction solution E, where the stirring speed is 500 rpm and the time is 3.2 h. Centrifuge, wash, and freeze-dry to obtain resveratrol / montmorillonite.

[0159] S3: Add triethylamine to toluene with a concentration of 2.8 mol / L. Add bis(aminopropyl)polydimethylsiloxane with a molar ratio of 1:3 to triethylamine and perfluorooctanesulfonyl fluoride with a molar ratio of 1:1 to bis(aminopropyl)polydimethylsiloxane to obtain reaction solution F. React at a constant temperature of 58 °C for 3.5 h to obtain a pretreated reaction solution. Wash with saturated sodium chloride solution and then vacuum-dry to obtain a modified liquid. Add acrylic resin to mix to obtain a fluorinated acrylic resin, where the mass ratio of bis(aminopropyl)polydimethylsiloxane to acrylic resin is 1:20.

[0160] S4: Mix the fluorinated acrylic resin with a curing agent, then add modified graphene / aluminum oxide, resveratrol / montmorillonite, PEG-400, Byk-306, and FoamStar SI 2210, and stir evenly to obtain a high weather-resistant solvent-free coating.

[0161] Comparative Example 1

[0162] This comparative example provides a preparation method of a high weather-resistant solvent-free coating. The difference from Example 1 is that in step S1, the mass ratio of graphite to potassium permanganate is adjusted to 1:6, and other operation steps and process parameters are exactly the same as those in Example 1.

[0163] Comparative Example 2

[0164] This comparative example provides a preparation method of a high weather-resistant solvent-free coating. The difference from Example 1 is that in step S1, the mass ratio of graphite to potassium permanganate is adjusted to 1:2, and other operation steps and process parameters are exactly the same as those in Example 1.

[0165] Comparative Example 3

[0166] This comparative example provides a preparation method of a high weather-resistant solvent-free coating. The difference from Example 1 is that in step S1, the molar ratio of perfluorooctanesulfonyl fluoride to bis(aminopropyl)polydimethylsiloxane is adjusted to 2:1.5, and other operation steps and process parameters are exactly the same as those in Example 1.

[0167] Comparative Example 4

[0168] This comparative example provides a preparation method of a high weather-resistant solvent-free coating. The difference from Example 1 is that in step S1, the mass ratio of graphite to potassium permanganate is adjusted to 0.2:1.5, and other operation steps and process parameters are exactly the same as those in Example 1.

[0169] Perform performance tests on the high weather-resistant solvent-free coatings of the above Examples 1-4 and Comparative Examples 1-4. The specific process is as follows:

[0170] Test the adhesion of the sample according to GB / T 9286-2021;

[0171] Test the ultraviolet aging resistance of the sample according to IOS 7724-2;

[0172] The test results are shown in Table 1.

[0173] Table 1: Performance test results of the high weather-resistant solvent-free coatings of Examples 1-4 and Comparative Examples 1-4

[0174]

[0175] As can be seen from Table 1, the high weather-resistant solvent-free coatings prepared in Examples 1-4 provided by the present invention have good adhesion and weather resistance.

[0176] From the test results of Example 1 and Comparative Examples 1 and 2, it can be obtained that when the feeding amount of potassium permanganate is too high, it will cause excessive oxidation of graphite, and the surface of the generated graphene oxide contains more carboxyl and hydroxyl groups. Although this improves the hydrophilicity, the oxidized functional groups are prone to further react with free radicals or corrosive media, exacerbating the degradation process of the coating and ultimately weakening the weather resistance of the coating; while when the feeding amount is too low, the oxidation degree is insufficient, the interlayer peeling of graphite is incomplete, the generated graphene sheets are thicker, and the dispersibility is poor, thus affecting the barrier performance of the coating and reducing its barrier ability to corrosive media.

[0177] From the test results of Example 1 and Comparative Examples 3 and 4, it can be obtained that by introducing perfluorooctanesulfonyl fluoride, fluorinated groups can be introduced into the molecular chain of the acrylic resin, which can effectively absorb or reflect ultraviolet rays, prevent the ultraviolet rays from causing photoaging of the coating substrate, and improve the weather resistance of the coating in the outdoor environment. When the amount of perfluorooctanesulfonyl fluoride is too much, it may lead to uneven distribution of the generated fluorinated groups on the molecular chain of the resin, thus affecting the performance consistency of the coating surface, making the surface of the coating too hydrophobic and the self-cleaning performance too strong, resulting in insufficient adhesion; while when the amount is too little, the introduction of the fluorinated structure is insufficient, resulting in insufficient resistance of the acrylic resin to chemical corrosion and ultraviolet rays, and the weather resistance of the coating decreases.

[0178] The above are only specific embodiments 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 fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A preparation method of a high weather-resistant solvent-free coating, characterized in that, The preparation method includes: S1: Under an ice-water bath, graphite and sodium nitrate are added to sulfuric acid, and then potassium permanganate is added to obtain reaction solution A. After constant-temperature reaction, reaction solution B is obtained. Hydrogen peroxide is added, and after washing and freeze-drying, graphene is obtained. Graphene and imidazole are added to deionized water, and then alumina nanoparticles are added to obtain reaction solution C. After ultrasonic treatment and reaction, reaction solution D is obtained. After filtration, washing, and drying, modified graphene / alumina is obtained; S2: Montmorillonite is added to a dimethyldiallylammonium chloride solution to obtain a dispersion. After reaction, filtration, washing, and drying, modified montmorillonite is obtained. A resveratrol ethanol solution is prepared, and the modified montmorillonite is added to the resveratrol ethanol solution to obtain a composite solution. After stirring reaction, reaction solution E is obtained. After centrifugation, washing, and freeze-drying, resveratrol / montmorillonite is obtained; S3: Triethylamine is added to toluene, and diaminopropyl polydimethylsiloxane and perfluorooctanesulfonyl fluoride are added to obtain reaction solution F. After constant-temperature reaction, a pretreated reaction solution is obtained. After washing with saturated sodium chloride solution and vacuum drying, a modified liquid is obtained. Acrylic resin is added and mixed to obtain fluorinated acrylic resin; S4: The fluorinated acrylic resin is mixed with a curing agent, and then modified graphene / alumina, resveratrol / montmorillonite, and an auxiliary agent are added and stirred evenly to obtain a high weather-resistant solvent-free coating; The mass ratio of the graphene to the alumina nanoparticles is 1:(0.5 - 1); The mass ratio of the resveratrol to the modified montmorillonite is 1:(1 - 5); The molar ratio of the perfluorooctanesulfonyl fluoride to the diaminopropyl polydimethylsiloxane is 1:(1 - 2).

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

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

4. The preparation method of a high weather resistance solvent-free coating according to claim 1, characterized in that, In S1: The mass ratio of the graphene to the imidazole is 1:(5 - 10).

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

6. The preparation method of a high weather resistance solvent-free coating according to claim 1, characterized in that, In S3: The molar ratio of the diaminopropyl polydimethylsiloxane to the triethylamine is 1:(1 - 3).

7. The preparation method of a high weather resistance solvent-free coating according to claim 1, characterized in that, In S3: The mass ratio of the diaminopropyl polydimethylsiloxane to the acrylic resin is 1:(10 - 20).

8. The preparation method of a high weather resistance 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 agent includes an emulsifier, a leveling agent, and an antifoaming agent; Among them, the emulsifier is OP-100 or PEG-400; The leveling agent is Byk-306 or perfluoroalkyl ester FC430; The antifoaming agent is an organosilicon antifoaming agent or FoamStar SI 2210.

9. A high weather-resistant solvent-free coating prepared by the preparation method according to any one of claims 1-8, characterized in that, The high weather-resistant solvent-free coating contains the following components in parts by mass: Fluorinated acrylic resin 50 - 80 parts; Modified graphene / alumina 5 - 15 parts; Resveratrol / montmorillonite 3 - 10 parts; Curing agent 10 - 20 parts; Auxiliary agent 2.2 - 5 parts; Wherein the auxiliaries include an emulsifier, a leveling agent and an antifoaming agent, with 2-4 parts of the emulsifier; 0.1-0.5 parts of the leveling agent; and 0.1-0.5 parts of the antifoaming agent.

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