Anti-fouling road marking composition based on hydrophobic nano-material and preparation method of anti-fouling road marking composition

Abstract

The invention discloses an anti-fouling road marking composition based on a hydrophobic nanometer material and a preparation method of the anti-fouling road marking composition, and belongs to the technical field of road marking materials. Comprising the following raw materials: selenol modified silicon dioxide, phosphonate modified nano titanium dioxide, a selenol-urethane acrylate hybrid, phosphonate-fluorosilicone urethane acrylate, a waterborne polyurethane dispersion and the like. The preparation method comprises the following steps: dispersing the nanofiller at a high speed, mixing the modified polymer and the film-forming substance, stirring, adjusting the viscosity and the like. The composition has a super-hydrophobic characteristic, and can effectively resist attachment of oil stains and dust; the modified polymer and the nanofiller are strongly combined through covalent bonds, and the adhesive force is excellent; meanwhile, good weather resistance is achieved, and aging is not prone to occurring after long-term use. The paint can be widely applied to road marking, and the anti-pollution performance and the service life of the marking are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road marking materials, and particularly relates to an anti-fouling road marking composition based on hydrophobic nanomaterial and a preparation method thereof. BACKGROUND

[0002] As the core identification of traffic infrastructure, road marking is long-term exposed to outdoor environment, and its anti-fouling performance directly affects traffic safety and identification clarity. Traditional road marking materials are mainly of hot melt type or solvent type, and such materials have high surface energy and strong affinity with pollutants such as oil stains, dust and gum, so that the pollutants are easily attached to the surface of the marking to form a stain layer, resulting in blurred marking and reduced reflective performance. Especially in the rainy season or humid environment, the pollutants are further penetrated after water absorption, which aggravates the failure of the marking, increases the maintenance cost, and may even cause traffic accidents. The anti-fouling defect of the traditional material has become the main bottleneck of the application of road marking.

[0003] In view of the anti-fouling deficiency of the traditional marking, the existing technology attempts to optimize it by surface modification or adding nanomaterial. Some schemes use fluorocarbon resin or silane coupling agent to improve the surface hydrophobicity, but the fluorocarbon resin is brittle and is easy to be pulverized and cracked under long-term irradiation of ultraviolet light, resulting in rapid decay of hydrophobicity; the silane coupling agent is combined with the film-forming material mainly through physical adsorption, and the interfacial bonding force is weak, so it is easy to migrate and lose during use, and cannot form a durable anti-fouling interface. Another technology introduces nanofillers (such as silicon dioxide and titanium dioxide) to construct a micro-nano rough structure to enhance the hydrophobicity, but the nanometer particles have poor compatibility with polymers, and are easy to agglomerate due to uneven dispersion, and the filler is easy to fall off after long-term use, which destroys the integrity of the coating and makes it difficult to stably maintain the anti-fouling effect.

[0004] In addition, the road environment is complex and changeable, and the marking needs to cope with rainwater scouring, snow-melting agent corrosion, heavy-load vehicle rolling and other multiple tests. The traditional marking material is easy to produce cracks under the action of environmental stress due to insufficient crosslinking density or poor flexibility of the film-forming material, forming a pollution penetration channel and further reducing the anti-fouling performance. Even if some improved schemes improve the short-term anti-fouling effect, the surface energy will rise again after long-term use due to coating aging (such as ultraviolet decomposition and oxidative degradation), and the pollutants will re-attach, which is difficult to meet the actual needs of long-term anti-fouling of road marking. In summary, it is an urgent need in the field of traffic infrastructure to develop a road marking material with strong anti-fouling property, high interfacial bonding force and excellent weather resistance. SUMMARY

[0005] The present application relates to the technical field of road marking materials, and particularly relates to an anti-fouling road marking composition based on hydrophobic nanomaterial and a preparation method thereof.

[0006] The present invention achieves the above objectives through the following technical solutions: A method for preparing an anti-fouling road marking composition based on hydrophobic nanomaterials, comprising the following steps: S1. Add selenosilane-modified silica and phosphonate-modified nano-titanium dioxide to a high-speed disperser and disperse, then add a dispersant and continue dispersing. S2. Mix the selenol-polyurethane acrylate hybrid, phosphonate-fluorosilicone polyurethane acrylate and waterborne polyurethane dispersion, heat to 60-62℃ and stir; add organosilicon defoamer and stir, then add aliphatic isocyanate, light calcium carbonate and talc and stir at low speed. S3. Finally, adjust the viscosity with deionized water and sieve.

[0007] In this invention, the overall preparation and performance optimization mechanism of the composition is described. During high-speed dispersion, selenol-modified silica and phosphonate-modified nano-titanium dioxide are uniformly dispersed under the action of a dispersant. The silanol hydroxyl groups (-Si-OH) on the surface of the nanoparticles combine with the hydrophilic groups of the dispersant to form a stable colloidal system, preventing filler agglomeration. In the mixing stage, the acrylate double bonds in the selenol-polyurethane acrylate hybrid and the phosphonate-fluorosilicone polyurethane acrylate undergo a prepolymerization reaction with the hydroxyl groups in the aqueous polyurethane dispersion to form a preliminary cross-linked network. The organosilicon defoamer adsorbs and breaks up bubbles in the system, reducing coating defects. The aliphatic isocyanate reacts with the hydroxyl groups or surface active sites in light calcium carbonate and talc to firmly anchor the filler in the polymer network, enhancing the mechanical strength of the coating. During viscosity adjustment, deionized water adjusts the fluidity of the system, making the coating easy to spread during construction; sieving removes large, undispersed particles, ensuring uniform coating thickness. Ultimately, the components work together through chemical bonds (such as urethane bonds and covalent bonds) and physical interactions (such as van der Waals forces) to form a multi-layered anti-fouling structure characterized by "low surface energy, micro-nano roughness, and strong interfacial bonding," thereby achieving long-lasting anti-fouling and weather-resistant performance of the markings.

[0008] A further improvement is that, in step S1, the high-speed disperser rotates at 1200-1500 rpm, and the dispersion time is 25-30 min; the continued dispersion time is 15-20 min.

[0009] A further improvement is that in step S2, the stirring time is 30-40 minutes after heating to 60-62℃; the stirring time is 8-10 minutes after adding the silicone defoamer; and the stirring speed is 400-500 rpm for 15-20 minutes.

[0010] A further improvement is that in step S3, the viscosity is 800-1200 mPa·s and passes through a 150-155 mesh sieve.

[0011] A further improvement is that the preparation method of the selenol-polyurethane acrylate hybrid includes: A1, adding polytetrahydrofuran diol and 4,4'-dicyclohexylmethane diisocyanate to a four-necked flask, purging with nitrogen for protection, heating to 74-76°C, and adding dibutyltin dilaurate for reaction; A2, adding 2-hydroxyethylselenool and hydroquinone, and continuing the reaction; cooling to 54-56°C, adding 3-glycidyl etheroxypropyltrimethoxysilane, and stirring until the system is homogeneous; cooling to room temperature, and adding hydroxyethyl acrylate for end capping.

[0012] In this invention, the synthesis mechanism of the selenol-polyurethane acrylate hybrid includes: polytetrahydrofuran diol and 4,4'-dicyclohexylmethane diisocyanate react under nitrogen protection and heated, where the isocyanate group (-NCO) undergoes a stepwise addition reaction with the hydroxyl group (-OH) of the polyol to form a polyurethane segment containing a urethane bond (-NH-CO-O-). During this process, dibutyltin dilaurate acts as a catalyst, lowering the activation energy and accelerating the growth of the polyurethane chain. The subsequently added 2-hydroxyethylselenool contains a selenol group (-SeH), whose hydroxyl group continues to undergo an addition reaction with the unreacted isocyanate group, introducing the selenol group into the polyurethane segment to form a selenol-containing functional end. The 3-glycidyl etheroxypropyltrimethoxysilane added after cooling contains epoxy groups (-O-), which can undergo cross-linking reactions with hydroxyl or urethane bonds in the polyurethane segments, enhancing intermolecular forces. Simultaneously, the siloxane segments of the silane (-Si(CH3)2O-) can form covalent bonds (such as -Si-O-Si-) with the silanol groups (-Si-OH) on the surface of the subsequently added nano-silica, achieving a strong bond between the polymer and the nanofiller. Finally, the added hydroxyethyl acrylate contains acrylate double bonds (-COO-CH=CH2), whose hydroxyl groups react with the remaining isocyanate groups, introducing the double bonds into the system and providing active sites for subsequent photocuring and cross-linking.

[0013] A further improvement is that the reaction time in step A1 is 2.5-3 hours.

[0014] A further improvement is that in step A2, the reaction continues for 3.5-4 hours, and the stirring time is 1.5-2 hours.

[0015] A further improvement is that the preparation method of the phosphonate-fluorosilicone polyurethane acrylate includes: B1, adding hexamethylene diisocyanate and polyethylene glycol to a four-necked flask, purging with nitrogen for protection, heating to 80-82°C, and adding dibutyltin dilaurate for reaction; B2, adding dimethyl methylphosphonate and p-tert-butylcatechol, and continuing the reaction; cooling to 60-62°C, adding 1H,1H,2H,2H-perfluorooctyltriethoxysilane, and stirring the system until homogeneous; cooling to room temperature, and adding hydroxyethyl acrylate for end capping.

[0016] In this invention, hexamethylene diisocyanate and polyethylene glycol react under nitrogen protection and heating. The isocyanate groups undergo stepwise addition with the hydroxyl groups of polyethylene glycol to form polyurethane segments containing urethane bonds. Dibutyltin dilaurate also acts as a catalyst to accelerate the reaction. Subsequently added dimethyl methylphosphonate contains phosphonate groups (-OP(O)(OCH3)2), whose methoxy groups (-OCH3) react with the hydroxyl groups or urethane bonds in the polyurethane segments, introducing phosphonate groups into the segments and imparting low surface energy properties to the material. After cooling, 1H,1H,2H,2H-perfluorooctyltriethoxysilane contains fluorosilicone segments (-Si(CH3)2O-CF2CF3), whose ethoxy groups (-OCH2CH3) hydrolyze to generate silanol groups (-Si-OH), which can crosslink with the hydroxyl groups or urethane bonds in the polyurethane segments. Simultaneously, the low surface energy properties of the fluorosilicone segments further enhance the hydrophobicity of the coating. The final addition of hydroxyethyl acrylate introduces acrylate double bonds into the system through the reaction of hydroxyl groups with the remaining isocyanate groups. Together with the double bonds in the selenol-polyurethane acrylate hybrid, it provides crosslinking activity for photocuring.

[0017] The further improvement is that in step B1, the reaction time is 2-4 hours; in step B2, the reaction time is 4-6 hours; and the stirring time is 2-4 hours.

[0018] The present invention also provides an anti-fouling road marking composition based on hydrophobic nanomaterials prepared by the preparation method described above. The anti-fouling road marking composition based on hydrophobic nanomaterials comprises the following raw materials in parts by weight: selenol-modified silica: 250-400 parts by weight; phosphonate-modified nano-titanium dioxide: 150-250 parts by weight; selenol-polyurethane acrylate hybrid: 120-280 parts by weight; phosphonate-fluorosilicone polyurethane acrylate: 100-220 parts by weight; waterborne polyurethane dispersion: 300-450 parts by weight; dispersant: 15-35 parts by weight; organosilicon defoamer: 8-20 parts by weight; aliphatic isocyanate: 50-100 parts by weight; light calcium carbonate: 200-350 parts by weight; talc: 80-150 parts by weight.

[0019] The beneficial effects of this invention are as follows: Road markings, exposed to the outdoors for extended periods, are prone to fading and becoming ineffective due to the adhesion of contaminants such as dust and oil. Traditional materials are easily wetted and adhered to by these substances, exhibiting insufficient resistance to dirt accumulation. This invention introduces hydrophobic nanomaterials with a finely textured surface into the coating, creating a structure resembling "micro-pits" on the surface. Simultaneously, the material itself possesses properties that prevent it from being wetted by water or oil. When contaminants fall onto the coating, they have difficulty penetrating these textured structures and are easily washed away by rainwater. Even after prolonged use, the coating surface maintains good resistance to dirt accumulation, effectively preserving the clarity of the markings.

[0020] In traditional road markings, nanofillers often detach due to poor adhesion to the coating, leading to coating damage and reduced stain resistance. In this invention, a specially modified polymer forms a tight chemical bond with the nanofillers, acting like an "invisible adhesive" to firmly fix the fillers within the coating. Even under prolonged rain or vehicle pressure, the fillers are less likely to detach, maintaining the integrity of the coating and resulting in a more durable and stable stain resistance.

[0021] In outdoor environments, factors such as ultraviolet radiation and de-icing agents can accelerate material aging, causing the coating to become brittle or its surface energy to rebound, leading to the re-adsorption of pollutants. The special polymer used in this invention contains functional segments with strong weather resistance (such as phosphorus- and fluorine-containing segments), which can effectively resist the decomposition and oxidation reactions of ultraviolet radiation, slowing down the aging process. Simultaneously, the coating's internal cross-linking reaction forms a dense network structure, acting like a "protective net" to prevent the penetration of moisture and corrosive substances, maintaining the coating's flexibility and strength. Even after long-term use, the coating maintains a smooth surface, is not prone to pollutant adhesion, extends the lifespan of the road markings, and reduces maintenance requirements. Detailed Implementation

[0022] The following detailed embodiments are only used to further illustrate this application and should not be construed as limiting the scope of protection of this application. Those skilled in the art can make some non-essential improvements and adjustments to this application based on the above application content.

[0023] I. Main Raw Materials and Equipment: The selenosilane-modified silica was purchased from Jiangsu Feixiang Chemical Co., Ltd., model FH-2021.

[0024] Phosphonate-modified nano-titanium dioxide was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., model AP-TP-02.

[0025] Polytetrahydrofuran diol was purchased from Wanhua Chemical Group Co., Ltd., model PTMG-2000.

[0026] 4,4'-Dicyclohexylmethane diisocyanate was purchased from Yantai Wanhua Polyurethane Co., Ltd., model HMDI-100.

[0027] The four-necked flask was purchased from Beijing Glass Instrument Factory; it is a 250mL standard ground glass flask.

[0028] Nitrogen was purchased from Air Liquide (China) Investment Co., Ltd., and is industrial-grade high-purity nitrogen (purity ≥99.99%).

[0029] Dibutyltin dilaurate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., model DBTDL-99 (catalyst grade).

[0030] 2-Hydroxyethylselenool was purchased from Hubei Xingfa Chemical Group Co., Ltd., model SE-200 (analytical grade).

[0031] Hydroquinone was purchased from Shanghai Reagent Factory No. 1, model HQ-99 (superior grade).

[0032] 3-Glycidyl etheroxypropyltrimethoxysilane was purchased from Nanjing Shuguang Chemical Group Co., Ltd., model KH-560 (industrial grade).

[0033] Hydroxyethyl acrylate was purchased from Jiangsu Sanmu Group Co., Ltd., model HEA-97 (industrial grade).

[0034] The waterborne polyurethane dispersion was purchased from Wanhua Chemical Group Co., Ltd., model WPU-500 (50% solid content).

[0035] The dispersant was purchased from Shanghai Xinanna Technology Co., Ltd., model DISP-190 (nonionic).

[0036] The silicone defoamer was purchased from Jiangsu Sixin Technology Development Co., Ltd., model S-088 (silicone type).

[0037] The aliphatic isocyanate was purchased from Wanhua Chemical Group Co., Ltd., model ADI-100 (industrial grade).

[0038] Light calcium carbonate was purchased from Hengfeng New Materials Co., Ltd. in Wanggao Industrial Zone, Hezhou, Guangxi. The model is LCC-500 (particle size ≤50μm).

[0039] The talc powder was purchased from Liaoning Haicheng Huayu Magnesium Products Co., Ltd., model TALC-200 (particle size ≤20μm).

[0040] Hexamethylene diisocyanate was purchased from Wanhua Chemical Group Co., Ltd., model HDI-100 (industrial grade).

[0041] The polyethylene glycol was purchased from Jiangsu Haian Petrochemical Co., Ltd., model PEG-1000 (industrial grade).

[0042] Dimethyl methylphosphonate was purchased from Hubei Xingfa Chemical Group Co., Ltd., model DMMP-99 (industrial grade).

[0043] p-tert-butylcatechol was purchased from Shanghai Reagent Factory No. 1, model TBC-99 (superior grade).

[0044] 1H,1H,2H,2H-perfluorooctyltriethoxysilane was purchased from Nanjing Shuguang Chemical Group Co., Ltd., model FAS-17 (industrial grade). II. Implementation Examples Example 1

[0045] 300g of selenol-modified silica and 200g of phosphonate-modified nano-titanium dioxide were added to a high-speed disperser and dispersed at 1300 rpm for 25 minutes to ensure uniform dispersion and initial wetting of the nanoparticles. Then, 20g of dispersant was added and dispersion continued for 15 minutes to form a stable nano-slurry. 200g of a pre-prepared selenol-polyurethane acrylate hybrid (prepared as follows: 200g of polytetrahydrofuran diol and 100g of 4,4'-dicyclohexylmethane diisocyanate were added to a four-necked flask, protected with high-purity nitrogen, heated to 75℃, and 0.5g of dibutyltin dilaurate was added as a catalyst. After reacting for 2.5 hours, the system...) The viscosity increased significantly, becoming semi-transparent; then 110g of 2-hydroxyethylselenool and 0.3g of hydroquinone were added, and the reaction continued for 3.5 hours, with intermittent stirring to prevent local overheating. The reaction endpoint was confirmed by infrared spectroscopy to have -NCO content approaching 0; the temperature was lowered to 55℃, and 30g of 3-glycidyl etheroxypropyltrimethoxysilane was added, and the mixture was stirred until the silane was hydrolyzed to generate silanol groups, which condensed with the hydroxyl groups of the polyurethane segments to form covalent bonds; after cooling to room temperature, 120g of hydroxyethyl acrylate was added for end-capping, and the reaction was continued for 1 hour until no obvious bubbles were visible in the system) and 150g of phosphonate-fluorosilicone polyurethane acrylate (the preparation process is as follows: take 100g of hexamethylene diisocyanate and 50g of polyethylene glycol were added to a four-necked flask, protected with high-purity nitrogen, and heated to 81°C. 0.5g of dibutyltin dilaurate was added to catalyze the reaction for 3 hours, during which the system gradually changed from a liquid to a semi-gel state. Subsequently, 110g of dimethyl methylphosphonate and 0.3g of p-tert-butylcatechol were added, and the reaction continued for 5 hours, with slow stirring to prevent rapid polymerization. The reaction endpoint was confirmed by titration to have an -NCO content below 0.5%. The temperature was lowered to 61°C, and 30g of 1H,1H,2H,2H-perfluorooctyltriethoxysilane was added, stirring until the silane was completely hydrolyzed and crosslinked with the polyurethane segments. After cooling to room temperature, propylene was added... 130g of hydroxyethyl ester (terminated and reacted for 1.2 hours until the system viscosity stabilized) was added to the above nano-slurry, mixed evenly, and then heated to 61℃ and stirred for 35 minutes to fully combine the modified polymer with the nanofiller. 12g of silicone defoamer was added and stirred for 9 minutes to eliminate micro-bubbles generated during the production process. Then, 75g of aliphatic isocyanate, 250g of light calcium carbonate, and 100g of talc were added and stirred at a low speed of 450rpm for 18 minutes to prevent filler sedimentation and promote cross-linking reaction. Finally, the system viscosity was adjusted to 1000mPa·s with deionized water, and large undispersed particles were removed by passing through a 150-mesh sieve to obtain the anti-fouling road marking composition. Example 2

[0046] The specific implementation method is the same as in Example 1, except that 350g of selenol-modified silica and 220g of phosphonate-modified nano-titanium dioxide are added to a high-speed disperser and dispersed at 1400rpm for 28min. Then, 25g of dispersant is added and dispersion is continued for 18min. 250g of selenol-polyurethane acrylate hybrid, 200g of phosphonate-fluorosilicone polyurethane acrylate and 400g of aqueous polyurethane dispersion are mixed and heated to 62℃ and stirred for 38min. 15g of organosilicon defoamer is added and stirred for 10min. 85g of aliphatic isocyanate, 300g of light calcium carbonate and 120g of talc are added and stirred at low speed (480rpm) for 20min. The viscosity is adjusted to 1100mPa·s with deionized water and passed through a 152-mesh sieve to obtain the composition. The preparation steps of the selenol-polyurethane acrylate hybrid are as follows: 220g of polytetrahydrofurandiol and 110g of 4,4'-dicyclohexylmethane diisocyanate are added to a four-necked flask, nitrogen gas is introduced for protection and the temperature is raised to 75℃, 0.6g of dibutyltin dilaurate is added and the reaction is carried out for 2.8h; 120g of 2-hydroxyethylselenool and 0.4g of hydroquinone are added and the reaction is continued for 3.8h, with stirring for 1.7h; the temperature is lowered to 55℃, 35g of 3-glycidyl etheroxypropyltrimethoxysilane is added and stirred evenly; the temperature is lowered to room temperature, and 130g of hydroxyethyl acrylate is added for end capping. The preparation steps of phosphonate-fluorosilicone polyurethane acrylate are as follows: 110g of hexamethylene diisocyanate and 60g of polyethylene glycol are added to a four-necked flask, nitrogen gas is introduced for protection and the temperature is raised to 82℃, 0.6g of dibutyltin dilaurate is added and reacted for 3.2h; 120g of dimethyl methylphosphonate and 0.4g of p-tert-butylcatechol are added and the reaction continues for 5.5h, with stirring for 3.5h; the temperature is lowered to 62℃, 35g of 1H,1H,2H,2H-perfluorooctyltriethoxysilane is added and stirred evenly; the temperature is lowered to room temperature, and 130g of hydroxyethyl acrylate is added for end capping. Example 3

[0047] The specific implementation method is the same as in Example 1, except that 280g of selenol-modified silica and 180g of phosphonate-modified nano-titanium dioxide are added to a high-speed disperser and dispersed at 1200rpm for 22min. Then, 15g of dispersant is added and dispersion is continued for 12min. 150g of selenol-polyurethane acrylate hybrid, 100g of phosphonate-fluorosilicone polyurethane acrylate and 300g of aqueous polyurethane dispersion are mixed and heated to 60℃ and stirred for 30min. 8g of organosilicon defoamer is added and stirred for 8min. 50g of aliphatic isocyanate, 200g of light calcium carbonate and 80g of talc are added and stirred at low speed (400rpm) for 15min. The viscosity is adjusted to 800mPa·s with deionized water and passed through a 150-mesh sieve to obtain the composition. The preparation steps of the selenol-polyurethane acrylate hybrid are as follows: 180g of polytetrahydrofurandiol and 90g of 4,4'-dicyclohexylmethane diisocyanate are added to a four-necked flask, nitrogen gas is introduced for protection and the temperature is raised to 74℃, 0.4g of dibutyltin dilaurate is added and reacted for 2.2h; 100g of 2-hydroxyethylselenool and 0.2g of hydroquinone are added and the reaction continues for 3.2h, with stirring for 1.2h; the temperature is lowered to 54℃, 25g of 3-glycidyl etheroxypropyltrimethoxysilane is added and stirred evenly; the temperature is lowered to room temperature, and 110g of hydroxyethyl acrylate is added for end capping. The preparation steps of phosphonate-fluorosilicone polyurethane acrylate are as follows: 90g of hexamethylene diisocyanate and 40g of polyethylene glycol are added to a four-necked flask, nitrogen gas is introduced for protection and the temperature is raised to 80℃, 0.4g of dibutyltin dilaurate is added and the reaction is carried out for 2.5h; 100g of dimethyl methylphosphonate and 0.2g of p-tert-butylcatechol are added and the reaction is continued for 4h, with stirring for 2h; the temperature is lowered to 60℃, 25g of 1H,1H,2H,2H-perfluorooctyltriethoxysilane is added and stirred evenly; the temperature is lowered to room temperature, and 110g of hydroxyethyl acrylate is added for end capping.

[0048] Comparative Example 1 The specific implementation method is the same as in Example 1, except that 300g of selenol-modified silica and 200g of phosphonate-modified nano-titanium dioxide are added to a high-speed disperser and dispersed at 1300rpm for 25min. Then, 20g of dispersant is added and dispersion is continued for 15min. 200g of ordinary polyurethane acrylate (unmodified), 150g of phosphonate-fluorosilicone polyurethane acrylate and 350g of waterborne polyurethane dispersion are mixed and heated to 61℃ and stirred for 35min. 12g of organosilicon defoamer is added and stirred for 9min. 75g of aliphatic isocyanate, 250g of light calcium carbonate and 100g of talc are added and stirred at low speed (450rpm) for 18min. The viscosity is adjusted to 1000mPa·s with deionized water and passed through a 150-mesh sieve to obtain the composition (selenool-polyurethane acrylate hybrid).

[0049] Comparative Example 2 The specific implementation method is the same as in Example 1, except that 300g of selenol-modified silica and 200g of phosphonate-modified nano-titanium dioxide are added to a high-speed disperser and dispersed at 1300rpm for 25min. Then, 20g of dispersant is added and dispersion is continued for 15min. 200g of selenol-polyurethane acrylate hybrid, 150g of ordinary fluorosilicone polyurethane acrylate (unmodified), and 350g of waterborne polyurethane dispersion are mixed and heated to 61℃ and stirred for 35min. 12g of organosilicon defoamer is added and stirred for 9min. 75g of aliphatic isocyanate, 250g of light calcium carbonate, and 100g of talc are added and stirred at low speed (450rpm) for 18min. The viscosity is adjusted to 1000mPa·s with deionized water and passed through a 150-mesh sieve to obtain the composition (phosphonate-free fluorosilicone polyurethane acrylate).

[0050] Comparative Example 3 The specific implementation method is the same as in Example 1, except that 300g of selenol-modified silica and 200g of phosphonate-modified nano-titanium dioxide are added to a high-speed disperser and dispersed at 1300rpm for 25min. Then, 20g of dispersant is added and dispersion is continued for 15min. 200g of ordinary polyurethane acrylate (unmodified), 150g of ordinary fluorosilicone polyurethane acrylate (unmodified), and 350g of waterborne polyurethane dispersion are mixed and heated to 61℃ and stirred for 35min. 12g of organosilicon defoamer is added and stirred for 9min. 75g of aliphatic isocyanate, 250g of light calcium carbonate, and 100g of talc are added and stirred at low speed (450rpm) for 18min. The viscosity is adjusted to 1000mPa·s with deionized water and passed through a 150-mesh sieve to obtain the composition (without the two modified compounds).

[0051] III. Performance Testing The anti-fouling road marking compositions prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests according to the following methods: 1. Stain Resistance Test (Static Contact Angle Method): The compositions of each example and comparative example were uniformly coated onto a clean glass plate (50mm × 50mm, 2mm thickness) and dried at room temperature for 24 hours to form a cured coating. Using a contact angle meter (model: DSA100), 5μL of deionized water (polar contaminant simulation solution) and 5μL of machine oil (non-polar contaminant simulation solution) were added respectively, and the static contact angle (θ) of the droplets on the coating surface was measured. The average value of 3 measurements was taken.

[0052] 2. Weather Resistance Test: The cured coating sample (100mm×100mm) was placed in a UV aging tester (model: Q-Lab QUV / se) and subjected to aging tests according to GB / T 1865-2009 standard (irradiance 0.89W / m², wavelength 340nm, black panel temperature 65℃, condensation cycle 4 hours / day). After aging for 500 hours, the sample was removed. The gloss at 60° before and after aging was measured using a gloss meter (model: BYK-GardnerMicro-Gloss 60°), and the gloss loss rate was calculated (gloss loss rate = (initial gloss - gloss after aging) / initial gloss × 100%). At the same time, the water contact angle after aging was remeasured using a contact angle meter.

[0053] 3. Adhesion test (cross-cut test): According to GB / T 9286-1998 standard, use a cross-cut tester (1mm spacing) to cut a grid on the surface of the cured coating. Apply 3M 600 tape to the grid area, and quickly peel off the tape vertically. Observe the coating peeling and evaluate the adhesion level (Level 0: no peeling; Level 1: ≤5% peeling; Level 2: 5%-15% peeling; Level 3: 15%-35% peeling; Level 4: 35%-65% peeling; Level 5: >65% peeling).

[0054] 4. Hardness test (pencil hardness method): According to GB / T 6739-2006 standard, use a pencil hardness tester (model: Mitsubishi UNI-HARDNESS Tester) to scratch the surface of the cured coating at a 45° angle and a pressure of 1kg, and record the hardest pencil model (such as Mitsubishi 9H, 7H, 5H, etc.) that can scratch the coating.

[0055] 5. Performance test results: Table 1: Performance test results of each embodiment and comparative example Group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Initial water contact angle (°) 168 172 165 135 142 128 Initial engine oil contact angle (°) 155 158 150 120 128 115 Water contact angle after UV aging for 500h (°) 152 155 148 110 115 98 Gloss loss rate (%) 2.1 1.8 2.5 18.5 15.2 22.7 Adhesion rating 0 level 0 level 0 level 2 level 1 level 3 level Pencil hardness 3H 3H 3H 2B 2H HB As shown in Table 1, Examples 1-3 significantly solved the technical problems of weak anti-fouling properties, filler detachment, and insufficient weather resistance in existing road markings by introducing two modified compounds: selenol-polyurethane acrylate hybrid and phosphonate-fluorosilicone polyurethane acrylate. Regarding anti-fouling properties, the initial water contact angle (165-172°) and oil contact angle (150-158°) of Examples 1-3 were much higher than those of Comparative Examples 1-3 (water contact angle 128-142°, oil contact angle 115-128°). Furthermore, after 500 hours of UV aging, the water contact angle only decreased by 16-17° (compared to a decrease of 25-30° in the comparative examples). This indicates that the modified compounds, by reducing surface energy and constructing a micro-nano rough structure, formed a dual anti-fouling interface of "low surface energy, micro-nano roughness," effectively resisting the adhesion of pollutants such as oil and dust. Regarding the issue of filler detachment, the adhesion grades of Examples 1-3 were all 0 (no detachment), and the pencil hardness reached 3H or higher. However, due to the lack of strong covalent bonds (such as selenol-oxygen bonds, phosphonate-silicon bonds) between the modified polymer and the nanofiller, the adhesion grades of Comparative Examples 1-3 dropped to 1-3 (partial detachment), and the pencil hardness was only 2B-HB. This indicates that the modified compound significantly enhanced the interfacial bonding force between the filler and the coating by forming covalent bonds with the nanofiller (such as selenol-modified silica, phosphonate-modified nano titanium dioxide), thus preventing filler detachment. Regarding weather resistance, the gloss loss rate after aging in Examples 1-3 was <2.6% (comparative examples 15-23%), and the surface energy recovery was small (contact angle decrease of only 16-17°). This indicates that the weather-resistant design of the phosphonate segment (-OP(O)(OCH3)2) and the fluorosilicone segment (-Si(CH3)2O-CF2CF3) effectively inhibited UV-induced aging degradation, delayed the recovery of coating surface energy and the re-adhesion of contaminants, and extended the service life of the marking. In summary, Examples 1-3, through the synergistic effect of the two modified compounds, comprehensively solved the core problems of traditional markings, such as weak dirt resistance, filler detachment, and insufficient weather resistance.

[0056] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing an anti-fouling road marking composition based on hydrophobic nanomaterials, characterized in that the steps include... include: S1. Add selenosilane-modified silica and phosphonate-modified nano-titanium dioxide to a high-speed disperser and disperse, then add a dispersant and continue dispersing. S2. Mix the selenol-polyurethane acrylate hybrid, phosphonate-fluorosilicone polyurethane acrylate and waterborne polyurethane dispersion, heat to 60-62℃ and stir; add organosilicon defoamer and stir, then add aliphatic isocyanate, light calcium carbonate and talc and stir at low speed. S3. Finally, adjust the viscosity with deionized water and sieve.

2. The preparation method according to claim 1, characterized in that, In step S1, the high-speed disperser rotates at 1200-1500 rpm, and the dispersion time is 25-30 min; the dispersion time continues for 15-20 min.

3. The preparation method according to claim 1, characterized in that, In step S2, the temperature is raised to 60-62℃ and the stirring time is 30-40 minutes; the silicone defoamer is added and the stirring time is 8-10 minutes; the low-speed stirring speed is 400-500 rpm and the stirring time is 15-20 minutes.

4. The preparation method according to claim 1, characterized in that, In step S3, the viscosity is 800-1200 mPa·s and passes through a 150-155 mesh sieve.

5. The preparation method according to claim 1, characterized in that, The preparation method of the selenol-polyurethane acrylate hybrid includes: A1, adding polytetrahydrofuran diol and 4,4'-dicyclohexylmethane diisocyanate into a four-necked flask, purging with nitrogen for protection, heating to 74-76°C, and adding dibutyltin dilaurate for reaction; A2, adding 2-hydroxyethylselenool and hydroquinone, and continuing the reaction; cooling to 54-56°C, adding 3-glycidyl etheroxypropyltrimethoxysilane, and stirring until the system is homogeneous; cooling to room temperature, and adding hydroxyethyl acrylate for end capping.

6. The preparation method according to claim 5, characterized in that, In step A1, the reaction time is 2.5-3 hours.

7. The preparation method according to claim 5, characterized in that, In step A2, the reaction continues for 3.5-4 hours; the stirring time is 1.5-2 hours.

8. The preparation method according to claim 1, characterized in that, The preparation method of the phosphonate-fluorosilicone polyurethane acrylate includes: B1, adding hexamethylene diisocyanate and polyethylene glycol into a four-necked flask, purging with nitrogen for protection, heating to 80-82℃, and adding dibutyltin dilaurate for reaction; B2, adding dimethyl methylphosphonate and p-tert-butylcatechol, and continuing the reaction; cooling to 60-62℃, adding 1H,1H,2H,2H-perfluorooctyltriethoxysilane, and stirring the system until homogeneous; cooling to room temperature, and adding hydroxyethyl acrylate for end capping.

9. The preparation method according to claim 8, characterized in that, In step B1, the reaction time is 2-4 hours; in step B2, the reaction time continues for 4-6 hours; the stirring time is 2-4 hours.

10. A pollution-resistant road marking composition based on hydrophobic nanomaterials prepared by the preparation method according to any one of claims 1-9, characterized in that, The anti-fouling road marking composition based on hydrophobic nanomaterials comprises the following raw materials in parts by weight: selenol-modified silica: 250-400 parts by weight; phosphonate-modified nano-titanium dioxide: 150-250 parts by weight; selenol-polyurethane acrylate hybrid: 120-280 parts by weight; phosphonate-fluorosilicone polyurethane acrylate: 100-220 parts by weight; waterborne polyurethane dispersion: 300-450 parts by weight; dispersant: 15-35 parts by weight; organosilicon defoamer: 8-20 parts by weight; aliphatic isocyanate: 50-100 parts by weight; light calcium carbonate: 200-350 parts by weight; talc: 80-150 parts by weight.