Weather-resistant stress-excited long-afterglow traffic marking coating and preparation method thereof

Abstract

The invention provides a weather-resistant stress-excited long-afterglow traffic marking coating and a preparation method thereof. According to the coating, SrAl2O4 (at) SiO2 (at) TiO2 / rGO of a core-shell satellite structure is used as a luminous functional material, and attapulgite, polymer resin and auxiliaries are combined to form a composite system. Through SiO2 coating and TiO2 / rGO satellite point modification, the water resistance and photocatalytic self-cleaning capability of the luminescent material are improved. Solvent-free polyurethane resin is adopted as a base material, and a light reflection microcavity structure is constructed in a coating through a process of spreading glass beads with different particle sizes step by step, so that long-acting afterglow luminescence under mechanical stress or light excitation is realized. The coating has excellent mechanical property, weather resistance and self-cleaning function, and solves the problem of poor environmental tolerance of traditional materials.

Description

Technical Field

[0001] This invention relates to the field of road traffic safety facility materials technology, and in particular to a traffic marking paint and its preparation method, specifically a long-afterglow traffic marking paint and its preparation method that combines stress-excited luminescence, long-lasting afterglow and high weather resistance. Background Technology

[0002] Traffic markings are a crucial infrastructure for guiding vehicle movement and ensuring road traffic safety. Traditional markings primarily rely on retroreflected light from vehicle headlights for nighttime visibility. However, their visibility drops drastically in rainy, foggy, or otherwise unsafe conditions, posing significant safety hazards. Long-afterglow luminescent materials offer a novel approach to addressing this issue, among which strontium aluminate (SrAl2O4:Eu) is a promising candidate. 2+ ,Dy 3+ ,Nd 3+ Due to its high brightness and long afterglow time, strontium aluminate has been widely studied for the preparation of luminous road markings, which can improve nighttime visibility. However, when this material is directly applied to outdoor traffic markings, it still faces two major technical bottlenecks. First, strontium aluminate itself is highly sensitive to water and atmospheric carbon dioxide, and is prone to hydrolysis to generate Al(OH)3, leading to a rapid decay of its luminous performance. Simultaneously, long-term outdoor ultraviolet radiation and diurnal temperature variations accelerate material aging and cause yellowing and chalking of the accompanying polymer resin substrate, jointly resulting in early failure of the road marking's luminous function. Specifically, the hydrolysis reaction will increase the pH value of the immersion solution to some extent, reducing the water resistance of the marking, while high-temperature environments will exacerbate thermal damage and inhibit energy release. While some researchers have proposed that surface modification techniques can partially improve water resistance, existing evaluation standards are mostly qualitative analyses, lacking quantitative data support and failing to meet practical application needs. Furthermore, most existing long-afterglow road markings rely on sunlight or vehicle headlights for "photoexcitation," and their "light storage-emission" process is constrained by ambient lighting conditions. In continuous rainy weather or low-light environments such as tunnels and underground parking garages, insufficient "light storage" leads to a significant decrease in luminescence performance. In recent years, researchers have attempted to develop "stress-luminescent" materials, which directly excite luminescence through mechanical stress from wheel rolling or friction, independent of lighting conditions, providing new possibilities for all-weather luminescent road markings. However, existing stress-luminescent materials generally suffer from short afterglow time and low luminescence intensity, failing to meet the application requirements for continuous guidance in traffic markings, and related research is still in the laboratory stage, lacking practical verification. Therefore, how to develop a new type of traffic marking coating that can simultaneously solve the two core problems of poor weather resistance and a single excitation method—that is, possessing excellent environmental durability, long-lasting stress-excited luminescence, and photoluminescence performance—has become a pressing technical challenge in this field. Summary of the Invention

[0003] The technical problem to be solved: The purpose of this invention is to provide a weather-resistant stress-excited long-afterglow traffic marking paint, which solves the problem of poor environmental durability of existing long-afterglow traffic marking paints and the problem of existing luminous markings having a single excitation method and being limited by ambient light.

[0004] Technical solution: A weather-resistant, stress-excited, long-afterglow traffic marking paint, by weight. Luminescent material for core-shell satellite structures: 20-35 parts; Attapulgite: 5-12 parts; Polymer resin material: 50-60 parts; Additives: 1-2 parts; in, The core of the luminescent material in the core-shell satellite structure is rare-earth-doped strontium aluminate (SrAl2O4):Eu 2+ ,Dy 3+ ,Nd 3+ The outer shell is made of 50-100 nm silicon dioxide, and the satellite points are TiO2 connected to a reduced graphene oxide network; The additives include leveling agents, defoamers, anti-aging agents, and catalysts.

[0005] The above-mentioned method for preparing a weather-resistant stress-excited long-afterglow traffic marking paint includes the following steps for the core-shell satellite structure luminescent material: S1. Weigh out Sr source, Al source, Eu source, Dy source and Nd source, mix and grind them with boric acid flux and activated carbon reducing agent, and calcine at 1250℃~1350℃ for 2~4h under a reducing atmosphere to obtain luminescent core SrAl2O4:Eu 2+ ,Dy 3+ ,Nd 3+ ; S2. The luminescent core from step S1 is dispersed in a mixed solution of ethanol, water and ammonia. The ethanol solution of tetraethyl orthosilicate is reacted at 40℃~60℃ for 6~12 h under stirring. After the reaction is completed, it is calcined at 500℃~600℃ for 2~4 h to form a shell structure, thereby obtaining the core-shell structure intermediate SrAl2O4@SiO2. S3. The core-shell structure intermediate described in step S2 is dispersed in a dilute acid aqueous solution, and an alcoholic solution of tetrabutyl titanate is added under stirring. The reaction temperature is 50℃~70℃ and the reaction time is 2~4h. After the reaction is completed, the intermediate SrAl2O4@SiO2@TiO2 with TiO2 nanodots on the surface is obtained by centrifugation, washing and drying. S4. Disperse the intermediate SrAl2O4@SiO2@TiO2 powder from step S3 in anhydrous ethanol, add silane coupling agent KH550, reflux at 60~70°C for 4~6h, centrifuge, wash and dry to obtain aminated SrAl2O4@SiO2@TiO2-NH2 powder, and disperse it in deionized water for later use; S5. The amino-modified SrAl2O4@SiO2@TiO2-NH2 aqueous dispersion from step S4 is mixed with the graphene oxide aqueous dispersion. The pH of the mixed solution is adjusted to 4-5 with acetic acid. The mixture is stirred at 70-80°C for 6-8 hours. Then, hydrazine hydrate is added, and the reaction is continued at 80-95°C for 2 hours to reduce the graphene oxide to reduced graphene oxide. Finally, the mixture is washed with water and dried to obtain SrAl2O4@SiO2@TiO2 / rGO.

[0006] The preparation method of the above-mentioned weather-resistant stress-excited long afterglow traffic marking paint includes the following steps: S11. Mix the core-shell satellite structure luminescent material, attapulgite, polymer resin a base material and additives, and after high-speed dispersion and vacuum degassing, obtain component A; mix with component B curing agent before use; S12. After applying the mixed coating obtained in S11 to the substrate, sprinkle high-refractive-index glass microspheres with a particle size of 500~800μm at a sprinkling rate of 300~600 g / m². 2 Then, transparent glass microspheres with a particle size of 100~300μm are spread at a rate of 150~300 g / m². 2 After curing, a composite coating with a microcavity structure is formed.

[0007] Preferably, the high-speed dispersion in step S11 has a rotation speed of 2000~3000 r / min and a time of 5~10 min.

[0008] Preferably, resin component A is polytetrahydrofuran diol with a molecular weight range of 400-3000, component B is HDI trimer curing agent, and the mass mixing ratio of component A to component B is 100:(15~25).

[0009] Preferably, in step S1, Al2O3 is weighed based on the molar amount of Sr in SrCO3, according to the molar ratio of Al:Sr=2:1, and Eu2O3, Dy2O3, and Nd2O3, equivalent to 0.5%~2% of the molar amount of Sr, are weighed for doping, respectively. The proportions of boric acid flux and activated carbon are 3%~5% and 1%~2% of the total weight of raw materials, respectively.

[0010] Preferably, the SrAl2O4 powder in step S2 is dispersed in a mixed solution of anhydrous ethanol, deionized water, and concentrated ammonia in a volume ratio of 1-5 g: 100 mL at a ratio of 80:18:2; and / or, The amount of tetraethyl orthosilicate used is 8% to 15% of the weight of SrAl2O4 powder.

[0011] Preferably, the SrAl2O4@SiO2 powder in step S3 is dispersed in a 1-2M dilute sulfuric acid aqueous solution at a ratio of 1-5g:50mL; and / or, tetrabutyl titanate is dissolved in 2-3 times its volume of anhydrous ethanol, and the amount of tetrabutyl titanate is 5%-10% of the weight of SrAl2O4@SiO2.

[0012] Preferably, in step S4, the amination treatment involves adding 1%-2% by weight of silane coupling agent KH550 to SrAl2O4@SiO2@TiO2; and / or, In step S5, the amount of GO added is 1%-3% of the weight of SrAl2O4@SiO2@TiO2-NH2, and the amount of hydrazine hydrate is 4-5 times that of GO.

[0013] Preferably, the additive is composed of the following components: 10-15 parts of polydimethylsiloxane leveling agent, 20-30 parts of polyether-modified polysiloxane defoamer, 20-30 parts of benzotriazole ultraviolet absorber, and 5-15 parts of dibutyltin dilaurate catalyst.

[0014] Beneficial effects: Compared with the prior art, the weather-resistant stress-excited long afterglow traffic marking paint and its preparation method provided by the present invention have the following beneficial effects: 1. This invention constructs a core-shell structure SrAl2O4@SiO2 with mesoporous silica as the outer shell. This inert and dense outer shell effectively blocks direct contact between environmental media such as water vapor and carbon dioxide and the core SrAl2O4 lattice, thereby fundamentally suppressing Eu. 2+ The hydrolysis and oxidation deactivation processes of ions extend the lifespan of luminescent materials in harsh outdoor environments.

[0015] 2. In this invention, the TiO2 nanodots and reduced graphene oxide (rGO) network on the periphery form a stress conduction pathway through chemical bonding. Mechanical stress, such as that caused by wheel crushing, can be efficiently transferred to the luminescent core through the rGO network, stimulating electron transitions. Simultaneously, the introduction of TiO2 and rGO enhances the material's absorption capacity for visible and ultraviolet light, improving photoexcitation efficiency. These two excitation modes complement each other, ensuring reliable luminescence of the markings under different environments.

[0016] 3. This invention utilizes a silane coupling agent to perform surface amination modification on SrAl2O4@SiO2@TiO2. Its organic functional groups can form a strong interfacial interaction with the molecular chains of polyurethane resin, effectively reducing interfacial defects between inorganic fillers and organic phases, avoiding coating cracking or flaking of luminescent materials caused by stress concentration, and improving the mechanical strength and service life of the coating.

[0017] 4. In this invention, attapulgite is used as a functional filler to construct a three-dimensional network structure. Through hydrogen bonding and physical adsorption, it effectively supports the core-shell satellite structure luminescent material, preventing it from settling and agglomerating. This ensures the stability of the coating during storage and the uniformity of its composition during construction, thus guaranteeing the consistency of the final coating's optical performance. Detailed Implementation

[0018] The present invention will be further described below with reference to embodiments. These embodiments are illustrative of the present invention, but the present invention is not limited to these embodiments: A weather-resistant, stress-excited, long-afterglow traffic marking paint, by weight, Luminescent material for core-shell satellite structures: 20-35 parts; Attapulgite: 5-12 parts; Polymer resin material: 50-60 parts; Additives: 1-2 parts; in, The core of the luminescent material in the core-shell satellite structure is rare-earth-doped strontium aluminate (SrAl2O4):Eu 2+ ,Dy 3+ ,Nd 3+ The outer shell is made of 50-100 nm silicon dioxide, and the satellite points are TiO2 connected to a reduced graphene oxide network; The additives include leveling agents, defoamers, anti-aging agents, and catalysts.

[0019] In the aforementioned weather-resistant stress-excited long afterglow traffic marking paint and its preparation method, rare earth-doped strontium aluminate is preferred as the luminescent matrix. 2+ As a luminescent center, it produces a highly efficient, long-lasting green afterglow; Dy 3+ and Nd 3+As a co-doper, it introduces deeper electron trap levels, prolonging the afterglow time and enhancing initial brightness and stress excitation sensitivity. Constructing a dense SiO2 shell on the surface of the luminescent core effectively isolates direct contact with water vapor and CO2, preventing hydrolysis of SrAl2O4, thereby improving the weather resistance and chemical stability of the luminescent material. The SiO2 shell coating reduces surface defects and non-radiative transition probability, helping to maintain high luminescence efficiency. The design of chemically bonding TiO2 satellite points to the rGO network is due to the high hardness and good stress response characteristics of TiO2 nanoparticles. Under mechanical stress such as from vehicle crushing, they can effectively concentrate and transfer stress to the luminescent core, exciting electrons in the traps. The stress-excited luminescence process utilizes the three-dimensional network structure formed by rGO, which not only provides a strong adhesion point for TiO2 but also serves as an electron channel due to its excellent conductivity. This facilitates carrier migration and energy transfer during stress excitation, further amplifying the stress excitation effect and enhancing the luminescence response. Attapulgite is chosen because it can form good dispersion in a polymer resin matrix, improving the mechanical strength, wear resistance, and impact resistance of the coating. For traffic markings subjected to frequent vehicle traffic, its abundant functional groups can adsorb coating components, preventing sedimentation and stratification. The polymer resin encapsulates and firmly bonds the aforementioned luminescent material and attapulgite, enabling it to form a tough, durable, and highly adhesive paint film on the road surface. Adding additives can optimize processing and durability.

[0020] The above-mentioned method for preparing a weather-resistant stress-excited long-afterglow traffic marking paint includes the following steps for the core-shell satellite structure luminescent material: S1. Weigh out Sr source, Al source, Eu source, Dy source and Nd source, mix and grind them with boric acid flux and activated carbon reducing agent, and calcine at 1250℃~1350℃ for 2~4h under a reducing atmosphere to obtain luminescent core SrAl2O4:Eu 2+ ,Dy 3+ ,Nd 3+ ; S2. The luminescent core from step S1 is dispersed in a mixed solution of ethanol, water and ammonia. The ethanol solution of tetraethyl orthosilicate is reacted at 40℃~60℃ for 6~12 h under stirring. After the reaction is completed, it is calcined at 500℃~600℃ for 2~4 h to form a shell structure, thereby obtaining the core-shell structure intermediate SrAl2O4@SiO2. S3. The core-shell structure intermediate described in step S2 is dispersed in a dilute acid aqueous solution, and an alcoholic solution of tetrabutyl titanate is added under stirring. The reaction temperature is 50℃~70℃ and the reaction time is 2~4h. After the reaction is completed, the intermediate SrAl2O4@SiO2@TiO2 with TiO2 nanodots on the surface is obtained by centrifugation, washing and drying. S4. Disperse the intermediate SrAl2O4@SiO2@TiO2 powder from step S3 in anhydrous ethanol, add silane coupling agent KH550, reflux at 60~70°C for 4~6h, centrifuge, wash and dry to obtain aminated SrAl2O4@SiO2@TiO2-NH2 powder, and disperse it in deionized water for later use; S5. The amino-modified SrAl2O4@SiO2@TiO2-NH2 aqueous dispersion from step S4 is mixed with the graphene oxide aqueous dispersion. The pH of the mixed solution is adjusted to 4-5 with acetic acid. The mixture is stirred at 70-80°C for 6-8 hours. Then, hydrazine hydrate is added, and the reaction is continued at 80-95°C for 2 hours to reduce the graphene oxide to reduced graphene oxide. Finally, the mixture is washed with water and dried to obtain SrAl2O4@SiO2@TiO2 / rGO.

[0021] In step S1 above, under the action of a reducing atmosphere and boric acid flux, the raw materials undergo solid-state ion diffusion and reaction to generate a well-crystallized strontium aluminate matrix. 3+ CO and other substances produced by activated carbon are reduced to luminescent Eu. 2+ And enter the lattice; Dy 3+ and Nd 3+ As a co-doper, it can jointly optimize long afterglow performance by introducing electron trap energy levels of different depths; In step S2 above, ammonia water acts as a catalyst to catalyze the hydrolysis and condensation of TEOS in an alkaline ethanol / water system. The product SiO2 is heterogeneously nucleated and grown on the surface of the luminescent core particles, eventually forming a dense, amorphous SiO2 protective shell. In step S3 above, the hydrolysis rate of tetrabutyl titanate under dilute acid catalysis is slowed down, which allows it to preferentially nucleate on the surface of the core-shell particles coated with SiO2, so that TiO2 is anchored on the SiO2 shell in the form of nanoscale satellite points, providing a basis for subsequent stress transfer. In step S4 above, the ethoxy group of KH550 hydrolyzes to generate silicon, which then undergoes dehydration condensation with Si-OH or Ti-OH on the surface of the core-shell particles to form strong Si-O-Si or Si-O-Ti covalent bonds, thereby stably introducing the amino group at the other end of KH550 onto the particle surface. This amination provides an active reaction site for the subsequent covalent connection with GO. In step S5 above, the carboxyl groups on the GO sheets are activated under acidic conditions and undergo an amidation condensation reaction with the amino groups introduced in step S4 to form covalent amide bonds, thereby chemically bonding the GO sheets to the particle surface. Hydrazine hydrate, as a strong reducing agent, significantly removes the oxygen-containing functional groups in the GO bonded to the particles, reducing them to rGO, which improves the conductivity of the material. Finally, a three-dimensional rGO network with good electron transport capability is constructed to coat the particles.

[0022] The preparation method of the above-mentioned weather-resistant stress-excited long afterglow traffic marking paint includes the following steps: S11. Mix the core-shell satellite structure luminescent material, attapulgite, polymer resin a base material and additives, and after high-speed dispersion and vacuum degassing, obtain component A; mix with component B curing agent before use; S12. After applying the mixed coating obtained in S11 to the substrate, sprinkle high-refractive-index glass microspheres with a particle size of 500~800μm at a sprinkling rate of 300~600 g / m². 2 Then, transparent glass microspheres with a particle size of 100~300μm are spread at a rate of 150~300 g / m². 2 After curing, a composite coating with a microcavity structure is formed.

[0023] In step S11 above, high shear force is used to ensure that the core-shell satellite structure luminescent material and attapulgite are uniformly dispersed in the polymer resin matrix, avoiding agglomeration and forming a homogeneous and stable mixture. Degassing eliminates air bubbles in the coating, ensuring that the paint film is dense and intact after curing. In step S12 above, glass microspheres of different sizes are spread in stages to construct a microcavity structure in the coating. This not only provides excellent immediate reflectivity, but also acts as a mechanical stress amplifier and a protective layer for luminescent materials, synergistically enhancing the stress-excited long afterglow performance and durability of the coating.

[0024] Preferably, resin component A is polytetrahydrofuran diol with a molecular weight range of 400-3000, component B is HDI trimer curing agent, and the mass mixing ratio of component A to component B is 100:(15~25). The polyol component, as the main resin, provides the flexible segments and hydroxyl groups required for the polymer network. The isocyanate curing agent, as a crosslinking agent, has highly reactive isocyanate groups that undergo a stepwise polymerization reaction with the hydroxyl groups of the polyol in component A to form a robust polyurethane network structure.

[0025] In one embodiment, in step S1, Al2O3 is weighed based on the molar amount of Sr in SrCO3, with a molar ratio of Al:Sr = 2:1. Then, 0.5%–2% of Eu2O3, 1%–3% of Dy2O3, and 0.5%–1.5% of Nd2O3 (equivalent to the molar amount of Sr) are weighed for doping. The proportions of boric acid flux and activated carbon are 3%–5% and 1%–2% of the total weight of the raw materials, respectively. In the Eu luminescent centers, the concentration directly affects the luminescence intensity. If the concentration is too low, there are insufficient luminescent centers, resulting in weak brightness; if the concentration is too high, a concentration quenching effect will occur. Co-doping with both in this ratio can construct a wider and more continuous trap energy level distribution. Boric acid, as a flux, melts at high temperatures to form a liquid phase, and an addition of 1–2% ensures a sufficient reducing atmosphere.

[0026] In one embodiment, the SrAl2O4 powder in step S2 is dispersed in a mixed solution composed of anhydrous ethanol, deionized water and concentrated ammonia in a volume ratio of 80:18:2 at a ratio of 1~5g:100mL; to ensure that the particles have sufficient dispersion space in the reaction system, the amount of tetraethyl orthosilicate is 8%~15% of the weight of SrAl2O4 powder, which determines the thickness of the SiO2 coating.

[0027] In one embodiment, the SrAl2O4@SiO2 powder from step S3 is dispersed in a 1-2M dilute sulfuric acid aqueous solution at a ratio of 1-5g:50mL; tetrabutyl titanate is dissolved in 2-3 times its volume of anhydrous ethanol, and the amount of tetrabutyl titanate is 5%-10% of the weight of SrAl2O4@SiO2. This dispersion ratio ensures that the SrAl2O4@SiO2 particles have good dispersibility in the reaction system, and the concentration of dilute sulfuric acid is to provide an acidic environment to catalyze the formation of satellite points on the SiO2 surface by sufficient tetrabutyl titanate.

[0028] In one embodiment, the amination treatment in step S4 involves adding 1%-2% by weight of silane coupling agent KH550 to SrAl2O4@SiO2@TiO2 to provide sufficient amino groups; in step S5, the amount of GO added is 1%-3% by weight of SrAl2O4@SiO2@TiO2-NH2 to ensure that the GO sheets can fully cover and effectively connect the amination particles; the amount of hydrazine hydrate is 4-5 times that of GO to drive the reduction reaction of GO as completely as possible, ensuring that the oxygen-containing functional groups (such as epoxy groups and carboxyl groups) on it are removed to the maximum extent, thereby efficiently and thoroughly reducing GO to highly conductive rGO.

[0029] In one embodiment, the additive comprises the following components: 10-15 parts of polydimethylsiloxane leveling agent to provide sufficient concentration to effectively reduce the surface tension of the coating; 20-30 parts of polyether-modified polysiloxane defoamer to provide sufficiently high efficiency and durability during high-speed dispersion and application; 20-30 parts of benzotriazole UV absorber to construct an effective UV protection barrier, capable of strongly absorbing high-energy UV photons and dissipating them as harmless heat energy; and 5-15 parts of dibutyltin dilaurate catalyst to effectively accelerate the cross-linking and curing reaction between isocyanate and hydroxyl groups.

[0030] Example 1 A weather-resistant, stress-excited, long-afterglow traffic marking paint, by weight, Luminescent materials for core-shell satellite structures: 30 parts; Attapulgite: 8 parts; Polymer resin material: 60 parts; Additives: 2 parts; in, The core of the luminescent material in the core-shell satellite structure is rare-earth-doped strontium aluminate (SrAl2O4):Eu 2+ ,Dy 3+ ,Nd 3+ The outer shell is made of 50 nm silicon dioxide, and the satellite points are made of TiO2 and connected to a reduced graphene oxide network by chemical bonding. The additives include 10 parts of leveling agent polydimethylsiloxane, 20 parts of defoamer polyether-modified polysiloxane, 20 parts of anti-aging agent benzotriazole ultraviolet absorber, and 5 parts of catalyst dibutyltin dilaurate catalyst.

[0031] The above-mentioned method for preparing a weather-resistant stress-excited long-afterglow traffic marking paint includes the following steps for the core-shell satellite structure luminescent material: S1. Weigh SrCO3 and Al2O3 in a 1:2 molar ratio, and add 0.5% Eu2O3, 1% Dy2O3, and 0.5% Nd2O3 (based on the molar weight of Sr), respectively. Simultaneously, add 3% boric acid flux and 1% activated carbon reducing agent (based on the total mass of raw materials). After mixing and grinding, calcine at 1250℃ for 2 h in a reducing atmosphere to obtain the luminescent core SrAl2O4:Eu 2+ ,Dy 3+ ,Nd 3+ ; S2. The SrAl2O4 luminescent core obtained in step S1 is dispersed in a mixed solution composed of anhydrous ethanol, deionized water and concentrated ammonia in a volume ratio of 80:18:2 at a ratio of 1g:100mL. Under stirring, an ethanol solution of tetraethyl orthosilicate equivalent to 8% of the weight of SrAl2O4 powder is added and reacted at 40℃ for 6h. Then, it is calcined at 500℃ for 2h to finally obtain the core-shell structure intermediate SrAl2O4@SiO2. S3. The SrAl2O4@SiO2 core-shell structure intermediate obtained in step S2 was dispersed in a 1M dilute sulfuric acid aqueous solution at a ratio of 1g:50mL. An ethanol solution of tetrabutyl titanate was added under stirring, wherein the amount of tetrabutyl titanate was 5% of the weight of the SrAl2O4@SiO2 powder and dissolved in 2 times the volume of anhydrous ethanol. After reacting at 50℃ for 2-4h, the intermediate was centrifuged, washed and dried to obtain the intermediate SrAl2O4@SiO2@TiO2 with TiO2 nanodots on the surface. S4. Disperse the SrAl2O4@SiO2@TiO2 powder obtained in step S3 in anhydrous ethanol, add 1% of silane coupling agent KH550 equivalent to 1% of the weight of SrAl2O4@SiO2@TiO2, reflux at 60°C for 4 hours, and after centrifugation, washing and drying, obtain aminated SrAl2O4@SiO2@TiO2-NH2 powder, and disperse it in deionized water for later use.

[0032] S5. The aminated SrAl2O4@SiO2@TiO2-NH2 aqueous dispersion obtained in step S4 is mixed with the graphene oxide aqueous dispersion, wherein the amount of graphene oxide added is 1% of the weight of SrAl2O4@SiO2@TiO2-NH2. The pH of the mixed solution is adjusted to 4-5 with acetic acid. After stirring and reacting at 70°C for 6 hours, hydrazine hydrate equivalent to 4 times the weight of graphene oxide is added. The reaction is continued at 80°C for 2 hours to reduce GO to reduced graphene oxide. Finally, the product SrAl2O4@SiO2@TiO2 / rGO is obtained by washing with water and drying.

[0033] The preparation method of the above-mentioned weather-resistant stress-excited long afterglow traffic marking paint includes the following steps: S11. After mixing the core-shell satellite structure luminescent material, attapulgite, polytetrahydrofuran diol with a molecular weight of 3000 and additives, disperse the mixture at a high speed of 2000 r / min for 5 min, and then degas it under vacuum to obtain component A. When using, mix component A with HDI trimer curing agent component B at a mass ratio of 100:15.

[0034] S12. After applying the mixed coating obtained in S11 to the substrate, sprinkle high-refractive-index glass microspheres with a particle size of 500 μm at a sprinkling rate of 300 g / m². 2 Then, transparent glass microspheres with a particle size of 100 μm were spread at a rate of 150 g / m². 2 After curing, a composite coating with a microcavity structure is formed.

[0035] Example 2

[0036] The difference between Example 2 and Example 1 is as follows: core-shell satellite structure luminescent material: 20 parts; attapulgite: 12 parts; polymer resin material: 50 parts; additives: 1 part.

[0037] Example 3

[0038] The difference between Example 3 and Example 1 is as follows: core-shell satellite structure luminescent material: 35 parts; attapulgite: 12 parts; polymer resin material: 55 parts; additives: 2 parts.

[0039] Example 4

[0040] The difference between Example 4 and Example 1 is that the proportions of boric acid flux and activated carbon in step S1 are 5% and 2% of the total weight of the raw materials, respectively.

[0041] Example 5

[0042] The difference between Example 5 and Example 1 is that the doping amounts of Eu, Dy and Nd in step S1 are 2%, 3% and 1.5% of the molar amount of Sr, respectively.

[0043] Example 6

[0044] The difference between Example 6 and Example 1 is that in step S2, the SrAl2O4 luminescent core is dispersed in the mixed solution at a ratio of 5g:100mL.

[0045] Example 7

[0046] The difference between Example 7 and Example 1 is that the amount of tetraethyl orthosilicate used in step S2 is 15% of the weight of SrAl2O4 powder.

[0047] Example 8

[0048] The difference between Example 8 and Example 1 is that the concentration of dilute sulfuric acid in step S3 is 2M.

[0049] Example 9

[0050] The difference between Example 9 and Example 1 is that the amount of tetrabutyl titanate used in step S3 is 10% of the weight of SrAl2O4@SiO2.

[0051] Example 10

[0052] The difference between Example 10 and Example 1 is that in step S5, the amount of GO added is 3% of the weight of SrAl2O4@SiO2@TiO2-NH2, and the amount of hydrazine hydrate is 5 times that of GO.

[0053] Example 11

[0054] The difference between Example 11 and Example 1 is that the mass mixing ratio of component A to component B in step S11 is 100:25.

[0055] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is as follows: core-shell satellite structure luminescent material: 10 parts; attapulgite: 30 parts; polymer resin material: 40 parts; additives: 1 part.

[0056] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is as follows: core-shell satellite structure luminescent material: 40 parts; attapulgite: 1 part; polymer resin material: 70 parts; additives: 1 part.

[0057] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the coating does not contain attapulgite.

[0058] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that TiO2 and rGO satellite point anchoring is not performed in the core-shell satellite structure luminescent material.

[0059] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that no chemical bonds (rGO) are formed in the core-shell satellite structure luminescent material.

[0060] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that the proportions of boric acid flux and activated carbon in step S1 are 10% and 5% of the total weight of the raw materials, respectively.

[0061] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is that the doping amounts of Eu, Dy and Nd in step S1 are 5%, 5% and 5% of the molar amount of Sr, respectively.

[0062] Comparative Example 8 The difference between Comparative Example 8 and Example 1 is that the amount of tetraethyl orthosilicate used in step S2 is 3% of the weight of SrAl2O4 powder.

[0063] Comparative Example 9 The difference between Comparative Example 9 and Example 1 is that the amount of tetrabutyl titanate used in step S3 is 20% of the weight of SrAl2O4@SiO2.

[0064] Comparative Example 10 The difference between Comparative Example 10 and Example 1 is that hydrazine hydrate reduction is not performed in step S3.

[0065] Comparative Example 11 The difference between Comparative Example 11 and Example 1 is that the mass mixing ratio of component A to component B in step S11 is 100:45.

[0066] Comparative Example 12 The difference between Comparative Example 12 and Example 1 is that only high-refractive-index glass microspheres are sprinkled in step S12.

[0067] Comparative Example 13 The difference between Comparative Example 13 and Example 1 is that only transparent glass microspheres are sprinkled in step S12.

[0068] Performance testing: Test Example 1 Initial afterglow intensity and afterglow retention: A spectrometer equipped with a photoluminescence excitation system and a weak light detector was used. After irradiating the sample under a standard D65 light source for 30 minutes, it was moved to a dark room, and its initial brightness (cd / m²) was immediately measured. 2 Record the brightness values ​​at 10 minutes, 60 minutes, 6 hours and 24 hours thereafter, and calculate the afterglow retention rate (6 hours / initial).

[0069] Weather resistance test: Following standard ASTM G154, a QUV accelerated aging test chamber was used. Test conditions: UVB-313 lamp, 8 hours of UV irradiation at 60°C, followed by 4 hours of condensation at 50°C as one cycle. After 500 hours of testing, the coating was observed for chalking, cracking, and discoloration, and the afterglow retention rate (relative to the initial value before aging) was measured.

[0070] Table 1 shows the optical performance tests.

[0071] As shown in Table 1, the coating in Comparative Example 1 had too little luminescent material, resulting in a decrease in initial strength and retention rate. In Comparative Example 2, the excessive resin and insufficient attapulgite led to uneven dispersion of the luminescent material and low stress transmission efficiency. Although the initial strength was not low, the decay was accelerated and the retention rate was poor. In Comparative Example 3, the stress excitation mechanism failed due to the absence of attapulgite, resulting in intrinsic afterglow without stress. In Comparative Example 4, the TiO2 / rGO-free coating had the worst performance, demonstrating that the stress localization electric field generated by TiO2 satellite points and the charge transport network of rGO can enhance stress excitation efficiency. In Comparative Example 5, the unbonded strength of the physically mixed rGO was better than that of Comparative Example 4 but much worse than that of Example 1, indicating that chemical bonding can provide efficient interfacial electronic coupling and stress transmission, while physical mixing easily leads to phase separation. The optimized doping in Example 5 achieved... The highest initial intensity; in Comparative Example 7, the 5% overdoping of each component resulted in a severe "concentration quenching" effect, with mutual interference between luminescent centers and a decrease in afterglow intensity; the increased SiO2 coating thickness in Example 6 and the increased TiO2 content in Example 9 provided better protection and more stress points, but the excessive amount in Comparative Example 9 may lead to an overly thick shell or TiO2 agglomeration, which in turn affects stress transmission and luminous efficiency; the excessively thin SiO2 in Comparative Example 8 would result in insufficient protection and poor weather resistance; Comparative Examples 12 and 13 used only single-size glass microspheres, and their afterglow performance and initial excitation brightness were lower than those of Example 1. The high-refractive-index microspheres mainly served as a reflective cavity to enhance light feedback, while the transparent microspheres acted as lenses to improve light convergence efficiency and initial retroreflection value. The two worked together to improve the vehicle headlight excitation efficiency and human eye observation brightness.

[0072] Performance Test 2: Abrasion resistance test: Refer to standard JT / T 712-2008 and use an abrasion testing machine. Record the abrasion value; the lower the abrasion value, the better the abrasion resistance.

[0073] Water resistance test: Immerse the coated sample in deionized water and soak it in a 40°C constant temperature water bath for 240 hours. Remove it, wipe the surface dry, and check for blistering, whitening, or peeling. Test its adhesion change and afterglow strength loss rate.

[0074] Coating viscosity: The viscosity of the mixture of component A was measured at 25°C.

[0075] Freezing stability: Component A was sealed and placed in environments of -5°C and -20°C for 7 days and 30 days respectively. After being restored to room temperature, the presence of agglomeration, flocculation, stratification, etc. was observed, and its redispersibility and coating performance were tested.

[0076] Table 2 shows the mechanical performance tests.

[0077] All examples exhibited excellent UV aging resistance, primarily attributed to the synergistic protection provided by the SiO2 / TiO2 / rGO structure. SiO2 isolates moisture and oxygen, while TiO2 and rGO efficiently absorb and scatter UV radiation. In contrast, Comparative Examples 4, 5, and 10 showed decreased weather resistance due to the lack of a TiO2 / rGO structure, chemical bonding of rGO, or the use of unreduced GO, respectively. Regarding mechanical properties, abrasion resistance mainly depends on the resin crosslinking density and the reinforcing effect of attapulgite. Example 11 exhibited the best abrasion resistance due to its high crosslinking density, while the excessive attapulgite in Comparative Example 1 led to increased material brittleness and insufficient resin matrix content. In Comparative Examples 2 and 3, the low or absent attapulgite content resulted in insufficient reinforcement, all contributing to poor abrasion resistance. Furthermore, the excessive curing agent in Comparative Example 11 resulted in an excessively high crosslinking density, increasing material brittleness and also negatively impacting abrasion resistance. Furthermore, Example 10 enhanced charge transport capability and weather resistance by increasing the amount of rGO; while the GO used in Comparative Example 10, due to its insulation and hydrophilicity, not only hindered charge transport but also introduced hygroscopicity, severely deteriorating the coating's water resistance and storage stability; in terms of water resistance, Comparative Example 3, lacking the nano-reinforcing effect of attapulgite, was more prone to water penetration and swelling, leading to blistering and peeling; the excessive attapulgite in Comparative Example 1 may form hydrophilic channels, causing slight whitening of the surface; and Comparative Example 10 also suffered from moisture absorption and decreased stability due to the hydrophilic properties of GO; in the freeze-thaw stability test, Comparative Example 1 showed caking due to filler sedimentation, while Comparative Examples 10 and 11 showed flocculation and paste formation due to chemical instability and excessive cross-linking, respectively, while all examples showed good stability.

[0078] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A weather-resistant, stress-excited, long-afterglow traffic marking paint, characterized in that: Portions by weight Luminescent material for core-shell satellite structures: 20-35 parts; Attapulgite: 5-12 parts; Polymer resin material: 50-60 parts; Additives: 1-2 parts; in, The core of the luminescent material in the core-shell satellite structure is rare-earth-doped strontium aluminate (SrAl2O4):Eu 2+ ,Dy 3+ ,Nd 3+ The outer shell is made of 50-100 nm silicon dioxide, and the satellite points are TiO2 connected to a reduced graphene oxide network; The additives include leveling agents, defoamers, anti-aging agents, and catalysts.

2. The preparation method of a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: The core-shell satellite structure luminescent material includes the following steps: S1. Weigh out Sr source, Al source, Eu source, Dy source and Nd source, mix and grind them with boric acid flux and activated carbon reducing agent, and calcine at 1250℃~1350℃ for 2~4h under a reducing atmosphere to obtain luminescent core SrAl2O4:Eu 2+ ,Dy 3+ ,Nd 3+ ; S2. The luminescent core from step S1 is dispersed in a mixed solution of ethanol, water and ammonia. The ethanol solution of tetraethyl orthosilicate is reacted at 40℃~60℃ for 6~12 h under stirring. After the reaction is completed, it is calcined at 500℃~600℃ for 2~4 h to form a shell structure, thereby obtaining the core-shell structure intermediate SrAl2O4@SiO2. S3. The core-shell structure intermediate described in step S2 is dispersed in a dilute acid aqueous solution, and an alcoholic solution of tetrabutyl titanate is added under stirring. The reaction temperature is 50℃~70℃ and the reaction time is 2~4h. After the reaction is completed, the intermediate SrAl2O4@SiO2@TiO2 with TiO2 nanodots on the surface is obtained by centrifugation, washing and drying. S4. Disperse the intermediate SrAl2O4@SiO2@TiO2 powder from step S3 in anhydrous ethanol, add silane coupling agent KH550, reflux at 60~70°C for 4~6h, centrifuge, wash and dry to obtain aminated SrAl2O4@SiO2@TiO2-NH2 powder, and disperse it in deionized water for later use; S5. The amino-modified SrAl2O4@SiO2@TiO2-NH2 aqueous dispersion from step S4 is mixed with the graphene oxide aqueous dispersion. The pH of the mixed solution is adjusted to 4-5 with acetic acid. The mixture is stirred at 70-80°C for 6-8 hours. Then, hydrazine hydrate is added, and the reaction is continued at 80-95°C for 2 hours to reduce the graphene oxide to reduced graphene oxide. Finally, the mixture is washed with water and dried to obtain SrAl2O4@SiO2@TiO2 / rGO.

3. The method for preparing a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: Includes the following steps: S11. Mix the core-shell satellite structure luminescent material, attapulgite, polymer resin a base material and additives, and after high-speed dispersion and vacuum degassing, obtain component A; mix with component B curing agent before use; S12. After applying the mixed coating obtained in S11 to the substrate, sprinkle high-refractive-index glass microspheres with a particle size of 500~800μm at a sprinkling rate of 300~600 g / m². 2 Then, transparent glass microspheres with a particle size of 100~300μm are spread at a rate of 150~300 g / m². 2 After curing, a composite coating with a microcavity structure is formed.

4. The preparation method of a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: The high-speed dispersion in step S11 is performed at a rotation speed of 2000~3000 r / min for 5~10 min.

5. The method for preparing a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: Resin component A is polytetrahydrofuran diol with a molecular weight range of 400-3000, component B is HDI trimer curing agent, and the mass mixing ratio of component A to component B is 100:(15~25).

6. The method for preparing a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: In step S1, Al2O3 is weighed based on the molar amount of Sr in SrCO3, according to the molar ratio of Al:Sr=2:

1. Then, Eu2O3, Dy2O3, and Nd2O3, which are equivalent to 0.5%~2% of the molar amount of Sr, are weighed for doping. The proportions of boric acid flux and activated carbon are 3%~5% and 1%~2% of the total weight of raw materials, respectively.

7. The preparation method of a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: In step S2, the SrAl2O4 powder is dispersed at a ratio of 1-5 g: 100 mL in a mixed solution composed of anhydrous ethanol, deionized water, and concentrated ammonia in a volume ratio of 80:18:2; and / or, The amount of tetraethyl orthosilicate used is 8% to 15% of the weight of SrAl2O4 powder.

8. The method for preparing a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: In step S3, the SrAl2O4@SiO2 powder is dispersed in a 1-2M dilute sulfuric acid aqueous solution at a ratio of 1-5g:50mL; and / or, tetrabutyl titanate is dissolved in 2-3 times its volume of anhydrous ethanol, with the amount of tetrabutyl titanate being 5%-10% of the weight of SrAl2O4@SiO2.

9. The preparation method of a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: In step S4, the amination treatment involves adding 1%-2% by weight of silane coupling agent KH550 to SrAl2O4@SiO2@TiO2; and / or, In step S5, the amount of GO added is 1%-3% of the weight of SrAl2O4@SiO2@TiO2-NH2, and the amount of hydrazine hydrate is 4-5 times that of GO.

10. The method for preparing a weather-resistant stress-excited long afterglow traffic marking paint according to claim 1, characterized in that: The additive is composed of the following components: 10-15 parts of polydimethylsiloxane leveling agent, 20-30 parts of polyether-modified polysiloxane defoamer, 20-30 parts of benzotriazole ultraviolet absorber, and 5-15 parts of dibutyltin dilaurate catalyst.

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