Quick-drying modified road marking paint and preparation method thereof

Abstract

The invention discloses a quick-drying modified road marking coating and a preparation method thereof, and belongs to the field of coating preparation, the preparation method comprises the following steps: weighing high-solid-content acrylic acid epoxy resin, adding a mixed solution of ethyl acetate and propylene glycol methyl ether acetate in batches, and adding a coalescing agent and a flatting agent to prepare first mixed resin; the preparation method comprises the following steps: pretreating nano silicon dioxide and carrying out surface modification on flaky mica to prepare a composite functional filler; adding the composite functional filler into the first mixed resin in three times to prepare second mixed resin; preparing to obtain a modified gallium indium tin liquid metal suspension; and sequentially adding nano zinc oxide, a thioxanthone photoinitiator and the modified gallium indium tin liquid metal suspension into the second mixed resin, and dispersing by using a planetary stirrer under a dark condition. The road marking paint prepared by the invention can effectively avoid the problem of marking pollution caused by electrostatic adsorption of dust.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular to a quick-drying modified road marking coating and a preparation method thereof. Background Art

[0002] Road marking paint is an important traffic safety facility, and its performance is directly related to the service life and safety of road markings. Existing road marking paints have problems such as slow drying, poor wear resistance, severe static electricity accumulation, and poor self-cleaning ability, which are difficult to meet actual application needs. Summary of the invention

[0003] One of the purposes of the present invention is to provide a method for preparing a quick-drying modified road marking paint, so as to solve the shortcomings of the road marking paint in the prior art, such as slow drying, poor wear resistance, serious static electricity accumulation, and poor self-cleaning ability.

[0004] The present invention is achieved by the following technical scheme. A method for preparing a quick-drying modified road marking paint comprises the following steps: S100, weighing a high-solid acrylic epoxy resin, adding a mixed solution of ethyl acetate and propylene glycol methyl ether acetate in portions, heating in a 45°C water bath and stirring for 30 minutes to prepare a first mixed solution, sequentially adding a film-forming aid and a leveling agent to the first mixed solution, and dispersing at high speed for 15 minutes using a paddle stirrer to prepare a first mixed resin; S200, pretreating nano-silicon dioxide and surface-modifying flaky mica to prepare a composite functional filler; S300, adding the pretreated nano-silicon dioxide to the surface of the flaky mica; Silicon oxide and modified flaky mica are added to the first mixed resin three times, each time with an interval of 5 minutes, and dispersed by a high-speed disperser to prepare a second mixed resin; S400, the modified gallium indium tin liquid metal is dispersed in a PMA / ethyl acetate mixed solvent with a volume ratio of 3:7, 0.05wt% sodium dodecyl sulfate is added, and the surface charge is adjusted to -45mV by a high-speed shear emulsifier to prepare a modified gallium indium tin liquid metal suspension; S500, nano zinc oxide, thioxanthone photoinitiator and modified gallium indium tin liquid metal suspension are added to the second mixed resin in sequence, and dispersed in a light-proof condition using a planetary mixer.

[0005] Furthermore, the mass ratio of the high solid acrylic epoxy resin to the mixed solution of ethyl acetate and propylene glycol methyl ether acetate in the first mixed solution is 2.13:1, and the volatile organic matter content is ≤280g / L.

[0006] Furthermore, the film-forming aid is ethylene glycol butyl ether, and the leveling agent is polyether-modified siloxane.

[0007] Furthermore, the pretreatment of the nano-silica includes: adding hydrophilic nano-silica and γ-aminopropyltriethoxysilane into anhydrous ethanol, treating with an ultrasonic stirrer for 30 minutes, filtering and activating the filtered material in a vacuum drying oven.

[0008] Further, the surface modification of the flaky mica includes:

[0009] The mica powder was immersed in an acetone solution containing a titanate coupling agent, reacted with magnetic stirring at 60°C, centrifuged and dried for later use.

[0010] Furthermore, step S300 further includes: maintaining the temperature ≤ 60° C. during the dispersion process, and sieving with 400 mesh after the dispersion is completed, so that the fineness of the prepared second mixed resin slurry is ≤ 25 μm.

[0011] Furthermore, the modified gallium indium tin liquid metal is a gallium indium tin eutectic liquid metal modified by a thiol-silane coupling agent.

[0012] Further, the thiol-silane coupling agent-modified gallium-indium-tin eutectic liquid metal is prepared by the following steps: S410, removing the Ga2O3 oxide layer on the surface of the gallium-indium-tin eutectic liquid metal by pickling, rinsing the reaction product with deionized water after the pickling, and placing the reactant in a vacuum drying oven to dry and remove surface free water after the rinse; S420, mixing the gallium-indium-tin eutectic liquid metal after pickling with ethylene glycol monobutyl ether, inputting the mixture into a microfluidic crusher, and cyclically treating the mixture 3 times to obtain gallium-indium-tin eutectic liquid metal nanodroplets; S430, using ethanol with a volume ratio of 9:1 / water mixed solution to dissolve mercaptopropyltrimethoxysilane, and adjust the solution to pH=4.5 with acetic acid to prepare a second mixed solution; S440, inject the gallium indium tin eutectic liquid metal nanodroplets into the second mixed solution, use a 45°C oil bath to react for 2 hours under nitrogen atmosphere protection, after the reaction, collect the reaction product by a centrifuge, and wash it three times with anhydrous ethanol to remove unreacted products, to prepare a thiol silane coupling agent modified gallium indium tin eutectic liquid metal, the molar ratio of the gallium indium tin eutectic liquid metal nanodroplets to the second mixed solution is 1:0.8.

[0013] Further, the pickling includes immersing the gallium indium tin eutectic liquid metal in a 5wt% dilute hydrochloric acid solution, heating the dilute hydrochloric acid solution to 50°C, and reacting it with magnetic stirring for 15 minutes; or immersing the gallium indium tin eutectic liquid metal in a 30wt% citric acid solution, heating the citric acid solution to 65°C, and reacting it with magnetic stirring for 20 minutes; or immersing the gallium indium tin eutectic liquid metal in a 20wt% oxalic acid solution, heating the oxalic acid solution to 65°C, and reacting it with magnetic stirring for 30 minutes.

[0014] Another aspect of the present invention further provides a quick-drying modified road marking paint, which is prepared according to the preparation method described above.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] 1. The coating of the present invention adopts high-solid acrylic epoxy resin as the base resin, and adds components such as photoinitiator and nano zinc oxide, so that the coating has excellent quick-drying performance, high construction efficiency, shortened road closure time, and reduced impact on traffic.

[0017] There are many defects in road marking paint, which meets the actual application needs.

[0018] 2. Composite functional fillers such as nano-silicon dioxide and modified mica flakes are added to the coating of the present invention, which endows the coating with excellent wear resistance, prolongs the service life of road markings, and reduces maintenance costs.

[0019] 3. The nano silicon dioxide and nano zinc oxide in the coating of the present invention have photocatalytic self-cleaning function, which gives the coating excellent self-cleaning performance, helps to maintain the cleanliness of the markings, and improves the recognition of the markings and the nighttime reflective performance.

[0020] 4. The present invention introduces modified gallium indium tin liquid metal into the coating, which has good conductivity and antistatic properties, and can effectively avoid the problem of electrostatic adsorption of dust causing marking pollution. After the gallium indium tin liquid metal is modified by MPTMS, a Ga-S covalent bond and a Si-O-Si network coating layer will be formed on the surface of the liquid metal, providing double protection. This modification can effectively improve the long-term stability of the coating, prevent metal oxidation and corrosion problems, and extend the service life of the coating. In addition, the MPTMS modification makes the liquid metal have better compatibility, especially compatibility with the resin matrix or other materials, avoiding the problems of phase separation and uneven dispersion, so that the liquid metal coating can be well combined with the resin substrate to provide a uniform coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0022] Figure 1 This is a flow chart of the method provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0024] Unless otherwise specified, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art in the art to which the present invention relates. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail. Regarding the "comprising", "including", "having", "containing", etc. used herein, they are all open terms, that is, they mean including but not limited to. Unless the context clearly indicates otherwise, the expressions "a" and "one" used herein include plural references. It should be noted that "first", "second", etc. are only for the convenience of description and distinction, and cannot be understood as indicating or implying relative importance. The term "about" used herein means a range of ±20% of the value thereafter. In some embodiments, the term "about" means a range of ±10% of the value thereafter. In some embodiments, the term "about" means a range of ±5% of the value thereafter.

[0025] Example 1

[0026] In this embodiment, a method for preparing a quick-drying modified road marking paint is disclosed. Figure 1 The flowchart of this embodiment is shown. It can be seen from the figure that this embodiment includes the following steps:

[0027] Step 1: Prepare the matrix resin, weigh a high-solid acrylic epoxy resin (solid content ≥ 75%, glass transition temperature Tg = 35°C), gradually add ethyl acetate (industrial grade, purity 99%) and propylene glycol methyl ether acetate (PMA) under stirring conditions to prepare a first mixed solution, keep the first mixed solution heated in a 45°C water bath, stir at 600 rpm for 30 minutes until the solution is transparent and free of particles, control the resin / solvent mass ratio to 80:37.5 (2.13:1), and the volatile organic compound (VOC) content ≤280 g / L.

[0028] Then, a film-forming aid and a leveling agent were added to the first mixed solution in sequence, and a paddle stirrer was used to disperse the mixture at high speed for 15 minutes to prepare a first mixed resin.

[0029] Step 2: Prepare the composite functional filler, first pre-treat the nano-silica and perform surface modification on the flaky mica.

[0030] The pretreatment includes adding hydrophilic nano-silica and gamma-aminopropyltriethoxysilane into anhydrous ethanol, treating the material with an ultrasonic stirrer for 30 minutes, and then activating the material in a vacuum drying oven.

[0031] The surface modification of flaky mica includes: immersing mica powder in an acetone solution containing a titanate coupling agent, reacting with magnetic stirring at 60° C., centrifuging and drying the solution for later use.

[0032] Step 3: Add the activated nano-silicon dioxide and modified mica flakes prepared in step 2 to the first mixed resin prepared in step 1 three times, with an interval of 5 minutes each time, and use a high-speed disperser to disperse for 40 minutes, and keep the temperature ≤60°C during the dispersion process. After the dispersion is completed, use a 400-mesh sieve to remove undispersed agglomerates to prepare a second mixed resin with a slurry fineness of ≤25μm.

[0033] Step 4: premix 6 vol% of modified gallium indium tin liquid metal and ammonium polyacrylate dispersant in ethylene glycol monobutyl ether, and process three times using a three-roll mill to obtain a uniform liquid metal suspension.

[0034] Specifically, the modified gallium indium tin liquid metal in this embodiment is prepared by the following steps:

[0035] 1) Oxide layer removal and pre-cleaning:

[0036] The gallium-indium-tin eutectic liquid metal is pickled to remove the oxide layer on the surface. Citric acid, oxalic acid or dilute hydrochloric acid can be used for pickling. The Ga2O3 oxide layer on the surface of the gallium-indium-tin eutectic liquid metal is removed by pickling.

[0037] After washing, the reaction product is rinsed with deionized water. After rinsing, the reactant is placed in a vacuum drying oven to dry to remove free water on the surface.

[0038] 2) The gallium indium tin eutectic liquid metal after acid washing is mixed with ethylene glycol monobutyl ether, input into a microfluidic crusher, and cycled for 3 times to obtain gallium indium tin eutectic liquid metal nanodroplets.

[0039] 3) Dissolve mercaptopropyltrimethoxysilane in a mixed solution of ethanol / water with a volume ratio of 9:1, adjust the pH to 4.5 with acetic acid, stir and complete the hydrolysis.

[0040] The gallium indium tin eutectic liquid metal nanodroplets were injected into the hydrolyzed mercaptopropyl trimethoxysilane solution, the molar ratio of the gallium indium tin eutectic liquid metal nanodroplets to the mercaptopropyl trimethoxysilane solution was 1:0.8, and the mixture was reacted in a 45°C oil bath under nitrogen atmosphere protection for 2 hours with continuous stirring.

[0041] After the reaction was completed, the reaction product was collected by a centrifuge and washed three times with anhydrous ethanol to remove the unreacted product, thereby obtaining a thiol-silane coupling agent-modified gallium-indium-tin eutectic liquid metal.

[0042] 4) The thiol-silane coupling agent-modified gallium-indium-tin eutectic liquid metal was newly dispersed in a PMA / ethyl acetate mixed solvent with a volume ratio of 3:7, 0.05wt% sodium dodecyl sulfate (SDS) was added, and the surface charge was adjusted to -45mV by a high-speed shear emulsifier (10000rpm×10min). A thiol-silane coupling agent-modified gallium-indium-tin eutectic liquid metal suspension was prepared.

[0043] Step 5: Add nano zinc oxide, thioxanthone photoinitiator and the uniform liquid modified gallium indium tin eutectic liquid metal suspension in step 4 to the second mixed resin in sequence, and disperse them under light-proof conditions using a planetary mixer to prepare a quick-drying modified road marking paint.

[0044] Example 2

[0045] Step 1: Prepare the base resin. Weigh 80 parts of high-solid acrylic epoxy resin, gradually add 30 parts of ethyl acetate (industrial grade, purity 99%) and 7.5 parts of propylene glycol methyl ether acetate (PMA) under stirring, maintain heating in a 50°C water bath, and stir at 600 rpm for 30 minutes until the system is transparent and free of particles.

[0046] Then, 5 parts of ethylene glycol butyl ether as a film-forming aid and 2 parts of polyether-modified siloxane as a leveling agent were added to the prepared resin-solvent mixed solution in sequence, and a paddle stirrer was used to disperse the mixture at a high speed of 1500 rpm for 15 minutes to prepare a base resin.

[0047] Step 2: preparing a composite functional filler, including pre-treating the nano-silica and surface modifying the flaky mica.

[0048] Specifically, the pretreatment includes adding 10 parts of hydrophilic nano-silica (particle size 20 nm, specific surface area 200 m² / g) and 0.5 parts of γ-aminopropyltriethoxysilane (KH550) into 20 parts of anhydrous ethanol, treating with an ultrasonic stirrer (power 600 W, frequency 28 kHz) for 30 minutes, and then activating in a vacuum drying oven at 80°C for 2 hours.

[0049] The surface modification of flaky mica includes: immersing 5 parts of mica powder (diameter-to-thickness ratio>80) in an acetone solution containing 1.5 parts of a titanate coupling agent (NDZ-201), reacting with magnetic stirring at 60°C for 1 hour, centrifuging and drying for later use.

[0050] Step 3: Add the activated nano-silica and modified mica flakes prepared in step 2 to the base resin prepared in step 1 three times, with an interval of 5 minutes each time, and disperse for 40 minutes using a high-speed disperser (speed 2500rpm, blade diameter 50mm), and keep the temperature ≤60°C during the process. Sieve (400 mesh) to remove undispersed agglomerates, and measure the slurry fineness ≤25μm (Hegman scraper instrument) to prepare a mixed base resin.

[0051] Step 4: 6 vol% modified gallium indium tin liquid metal (LM@MPTMS, particle size 100 nm) was premixed with 0.15 parts of ammonium polyacrylate dispersant in ethylene glycol monobutyl ether and milled using a three-roll mill (roller spacing 0.05 mm, shear rate 10 4 s⁻¹) for 3 times to obtain a uniform liquid metal suspension.

[0052] Specifically, the modified gallium indium tin liquid metal in this embodiment is prepared by the following steps:

[0053] 1) Oxide layer removal and pre-cleaning:

[0054] First, the gallium indium tin eutectic liquid metal is pickled to remove the oxide layer on the surface. In this embodiment, 100g of gallium indium tin eutectic liquid metal (Ga62.5In21.5Sn16, melting point 10.8°C) is immersed in a 5wt% dilute hydrochloric acid (HCl) solution, and the dilute hydrochloric acid solution is heated to 50°C, and magnetic stirring is used to react for 15 minutes, and the surface Ga2O3 oxide layer is removed by acid etching.

[0055] After the acid wash, the reaction product was rinsed with deionized water for 3 times and then placed in a vacuum drying oven (temperature 30 °C / -0.1 MPa) for 20 min to remove surface free water.

[0056] 2) The acid-washed LM was mixed with 200 ml of ethylene glycol monobutyl ether, input into a microfluidic crusher (shear pressure 150 MPa, channel diameter 50 μm), and the treatment was repeated three times to obtain LM nanodroplets with a particle size of D50 = 100 nm.

[0057] It should be noted that in this step, the oxide layer thickness can be reduced from 80 nm to <2 nm (confirmed by XPS characterization) by treatment with dilute hydrochloric acid; diethylene glycol monobutyl ether is used as a co-solvent to ensure compatibility with the resin matrix of step 1 and prevent phase separation.

[0058] 3) Dissolve 3.2 g of mercaptopropyltrimethoxysilane (MPTMS) in 100 ml of ethanol / water (volume ratio 9:1) mixed solution, adjust the pH to 4.5 with acetic acid, and complete the hydrolysis by magnetic stirring at 35°C for 1 hour.

[0059] The LM nanodroplets were slowly injected into the hydrolyzed MPTMS solution (the molar ratio of LM:MPTMS = 1:0.8), nitrogen was introduced for protection, and the reaction was carried out in a 45°C oil bath for 2 hours, during which stirring was continuously performed at 800 rpm.

[0060] After the reaction, the modified LM (MPTMS@LM) was collected by centrifugation (12000rpm×15min), and washed three times with anhydrous ethanol to remove the unreacted products, thereby preparing the thiol-silane coupling agent-modified gallium-indium-tin eutectic liquid metal (modified MPTMS@LM).

[0061] It should be noted that the thiol group (-SH) of MPTMS forms a Ga-S covalent bond (bond energy ≈ 240 kJ / mol) with the fresh Ga atoms on the surface of LM, and the methoxy group is hydrolyzed to form a Si-O-Si network to coat LM, achieving dual protection of physical barrier and chemical passivation (anti-secondary oxidation).

[0062] 4) The modified MPTMS@LM was redispersed in a mixed solvent of PMA / ethyl acetate (volume ratio 3:7), 0.05 wt% sodium dodecyl sulfate (SDS) was added, and the surface charge was adjusted to -45 mV by a high-speed shear emulsifier (10000 rpm × 10 min).

[0063] Particle size stability verification: Dynamic light scattering (DLS) was used to monitor the suspension to ensure that the particle size growth was ≤15% after 7 days of storage (an increase from D50=180nm to 207nm was considered acceptable).

[0064] It should be noted that the anionic properties of SDS and the thiol group of MPTMS synergistically enhance the electrostatic stabilization effect; the PMA solvent matches the resin system in step 1 to avoid introducing a new solvent to disrupt the balance of the formula.

[0065] Step 5: Add 2.5 parts of nano zinc oxide (ZnO, photocatalytic grade, particle size 30 nm), 0.6 parts of thioxanthone photoinitiator (ITX) and the uniform liquid metal suspension in step 4 to the mixed matrix resin in sequence, and use a planetary mixer (revolution 30 rpm, rotation 1200 rpm) to disperse for 45 minutes under light-proof conditions to prepare a quick-drying modified road marking paint.

[0066] It should be noted that in this embodiment, the gallium indium tin eutectic liquid metal is modified by a thiol-based silane coupling agent, which can not only form a strong interface bond with the resin matrix, but also significantly improve the curing efficiency of the coating, thereby achieving a quick-drying effect. Its specific mechanism of action is that the intrinsic thermal conductivity of the gallium indium tin eutectic liquid metal is much higher than that of the resin matrix. By adding the modified gallium indium tin eutectic liquid metal to the resin matrix, an efficient heat conduction network can be formed in the coating. During construction, the modified LM quickly transfers heat to the inside of the coating through a uniformly dispersed heat path, which can significantly shorten the activation time of the resin cross-linking reaction. At the same time, in the solvent volatilization stage, the surface modification layer of the LM nanodroplets can stabilize the Pickering emulsion structure, ensure that the solvent molecules (such as xylene, ethyl acetate) escape quickly through nanoscale channels, and increase the volatilization rate of the solvent. And by uniformly mixing the modified LM in the resin matrix, a thermal conductivity network of LM is formed in the layer, thereby promoting uniform diffusion of heat from the surface to the inside, so that the glass transition time of the resin is shortened.

[0067] Example 3

[0068] Step 1: Prepare the base resin. Weigh 90 parts of high-solid acrylic epoxy resin (, gradually add 35 parts of ethyl acetate (industrial grade, purity 99%) and 10 parts of propylene glycol methyl ether acetate (PMA) under stirring, maintain heating in a water bath at 55°C, and stir at 600 rpm for 30 minutes until the system is transparent and free of particles.

[0069] Then, 6 parts of ethylene glycol butyl ether as a film-forming aid and 3 parts of polyether-modified siloxane as a leveling agent were added in sequence to the prepared resin-solvent mixed solution, and a paddle stirrer was used to disperse the mixture at a high speed of 1000 rpm for 20 minutes to prepare a base resin.

[0070] Step 2: preparing a composite functional filler, including pre-treating the nano-silica and surface modifying the flaky mica.

[0071] Specifically, the pretreatment includes adding 15 parts of hydrophilic nano-silica (particle size 20 nm, specific surface area 200 m² / g) and 1.5 parts of γ-aminopropyltriethoxysilane (KH550) into 25 parts of anhydrous ethanol, treating with an ultrasonic stirrer (power 600 W, frequency 28 kHz) for 40 minutes, and then activating in a vacuum drying oven at 85°C for 1.5 hours.

[0072] The surface modification of flaky mica includes: immersing 10 parts of mica powder (diameter-to-thickness ratio>80) in an acetone solution containing 3 parts of titanate coupling agent (NDZ-201), reacting with magnetic stirring at 60°C for 1 hour, centrifuging and drying for later use.

[0073] Step 3: Add the activated nano-silica and modified mica flakes prepared in step 2 to the base resin prepared in step 1 three times, with an interval of 5 minutes each time, and disperse for 40 minutes using a high-speed disperser (speed 2500rpm, blade diameter 50mm), and keep the temperature ≤60°C during the process. Sieve (400 mesh) to remove undispersed agglomerates, and measure the slurry fineness to be ≤25μm to prepare a mixed base resin.

[0074] Step 4: 6 vol% modified gallium indium tin liquid metal (LM@MPTMS, particle size 150 nm) was premixed with 0.15 parts of ammonium polyacrylate dispersant in ethylene glycol monobutyl ether and milled using a three-roll mill (roller spacing 0.05 mm, shear rate 10 4 s⁻¹) for 3 times to obtain a uniform liquid metal suspension.

[0075] Specifically, the modified gallium indium tin liquid metal in this embodiment is prepared by the following steps:

[0076] 1) Oxide layer removal and pre-cleaning:

[0077] First, the gallium indium tin eutectic liquid metal is pickled to remove the surface oxide layer. In this embodiment, 100g of gallium indium tin eutectic liquid metal (Ga62.5In21.5Sn16, melting point 10.8°C) is immersed in a 30wt% citric acid solution, the citric acid solution is heated to 65°C, and magnetic stirring is used to react for 20 minutes, and the surface Ga2O3 oxide layer is removed by acid etching.

[0078] After the acid wash, the reaction product was rinsed with deionized water for 3 times and then placed in a vacuum drying oven (temperature 30 °C / -0.1 MPa) for 20 min to remove surface free water.

[0079] 2) The acid-washed LM was mixed with 200 ml of ethylene glycol monobutyl ether, input into a microfluidic crusher (shear pressure 150 MPa, channel diameter 50 μm), and the treatment was repeated three times to obtain LM nanodroplets with a particle size of D50 = 150 nm.

[0080] 3) Dissolve 3.2 g of mercaptopropyltrimethoxysilane (MPTMS) in 100 ml of a 9:1 ethanol / water mixed solution, adjust the pH to 4.5 with acetic acid, and complete the hydrolysis by magnetic stirring at 40°C for 1 hour.

[0081] The LM nanodroplets were slowly injected into the hydrolyzed MPTMS solution (the molar ratio of LM:MPTMS = 1:0.8), nitrogen was introduced for protection, and the reaction was carried out in a 45°C oil bath for 2 hours, during which stirring was continuously performed at 800 rpm.

[0082] After the reaction, the modified LM (MPTMS@LM) was collected by centrifugation (12000rpm×15min), and washed three times with anhydrous ethanol to remove the unreacted products, thereby preparing the thiol-silane coupling agent-modified gallium-indium-tin eutectic liquid metal (modified MPTMS@LM).

[0083] It should be noted that the thiol group (-SH) of MPTMS forms a Ga-S covalent bond (bond energy ≈ 240 kJ / mol) with the fresh Ga atoms on the surface of LM, and the methoxy group is hydrolyzed to form a Si-O-Si network to coat LM, achieving dual protection of physical barrier and chemical passivation (anti-secondary oxidation).

[0084] 4) The modified MPTMS@LM was redispersed in a mixed solvent of PMA / ethyl acetate (volume ratio 3:7), 0.05 wt% sodium dodecyl sulfate (SDS) was added, and the surface charge was adjusted to -45 mV by a high-speed shear emulsifier (10000 rpm × 10 min).

[0085] Step 5: Add 2.5 parts of nano zinc oxide (ZnO, photocatalytic grade, particle size 30 nm), 0.6 parts of thioxanthone photoinitiator (ITX) and the uniform liquid metal suspension in step 4 to the mixed matrix resin in sequence, and use a planetary mixer (revolution 30 rpm, rotation 1200 rpm) to disperse for 45 minutes under light-proof conditions to prepare a quick-drying modified road marking paint.

[0086] Example 4

[0087] Step 1: Prepare the base resin. Weigh 70 parts of high-solid acrylic epoxy resin, gradually add 25 parts of ethyl acetate (industrial grade, purity 99%) and 15 parts of propylene glycol methyl ether acetate (PMA) under stirring, maintain heating in a water bath at 60°C, and stir at 1000 rpm for 20 minutes until the system is transparent and free of particles.

[0088] Then, 7 parts of ethylene glycol butyl ether as a film-forming aid and 3 parts of polyether-modified siloxane as a leveling agent were added in sequence to the prepared resin-solvent mixed solution, and a paddle stirrer was used to disperse the mixture at a high speed of 1000 rpm for 15 minutes to prepare a base resin.

[0089] Step 2: preparing a composite functional filler, including pre-treating the nano-silica and surface modifying the flaky mica.

[0090] The pretreatment includes adding 10 parts of hydrophilic nano-silica with a particle size of 20 nm and a specific surface area of ​​200 m2 / g and 0.5 parts of γ-aminopropyltriethoxysilane to 20 parts of anhydrous ethanol, treating with an ultrasonic stirrer (power 600 W, frequency 28 kHz) for 30 minutes, and then activating in a vacuum drying oven at 75°C for 2 hours.

[0091] The surface modification of flaky mica includes: immersing 5 parts of mica powder (diameter-to-thickness ratio>80) in an acetone solution containing 1.5 parts of a titanate coupling agent (NDZ-201), reacting with magnetic stirring at 60°C for 1 hour, centrifuging and drying for later use.

[0092] Step 3: Add the activated nano-silica and modified mica flakes prepared in step 2 to the base resin prepared in step 1 three times, with an interval of 5 minutes each time, and disperse for 40 minutes using a high-speed disperser (speed 2500rpm, blade diameter 50mm), and keep the temperature ≤60°C during the process. Sieve (400 mesh) to remove undispersed agglomerates, and measure the slurry fineness to be ≤25μm to prepare a mixed base resin.

[0093] Step 4: 6 vol% modified gallium indium tin liquid metal (LM@MPTMS, particle size 180 nm) was premixed with 0.15 parts of ammonium polyacrylate dispersant in ethylene glycol monobutyl ether and milled using a three-roll mill (roller spacing 0.05 mm, shear rate 10 4 s⁻¹) for 3 times to obtain a uniform liquid metal suspension.

[0094] Specifically, the modified gallium indium tin liquid metal in this embodiment is prepared by the following steps:

[0095] 1) Oxide layer removal and pre-cleaning:

[0096] First, the gallium indium tin eutectic liquid metal is pickled to remove the oxide layer on the surface. In this embodiment, 100g of gallium indium tin eutectic liquid metal (Ga62.5In21.5Sn16, melting point 10.8°C) is immersed in a 20wt% oxalic acid solution, the oxalic acid solution is heated to 65°C, and magnetic stirring is used to react for 30 minutes, and the surface Ga2O3 oxide layer is removed by acid etching.

[0097] After the acid wash, the reaction product was rinsed with deionized water for 3 times and then placed in a vacuum drying oven (temperature 30 °C / -0.1 MPa) for 20 min to remove surface free water.

[0098] 2) The acid-washed LM was mixed with 200 ml of ethylene glycol monobutyl ether, input into a microfluidic crusher (shear pressure 150 MPa, channel diameter 50 μm), and the treatment was repeated three times to obtain LM nanodroplets with a particle size of D50 = 180 nm.

[0099] 3) Dissolve 3.2 g of mercaptopropyltrimethoxysilane (MPTMS) in 100 ml of a 9:1 ethanol / water mixed solution, adjust the pH to 4.5 with acetic acid, and complete the hydrolysis by magnetic stirring at 40°C for 1 hour.

[0100] The LM nanodroplets were slowly injected into the hydrolyzed MPTMS solution (the molar ratio of LM:MPTMS = 1:0.8), nitrogen was introduced for protection, and the reaction was carried out in a 45°C oil bath for 2 hours, during which stirring was continuously performed at 800 rpm.

[0101] After the reaction, the modified LM (MPTMS@LM) was collected by centrifugation (12000rpm×15min), and washed three times with anhydrous ethanol to remove the unreacted products, thereby preparing the thiol-silane coupling agent-modified gallium-indium-tin eutectic liquid metal (modified MPTMS@LM).

[0102] 4) The modified MPTMS@LM was redispersed in a mixed solvent of PMA / ethyl acetate (volume ratio 3:7), 0.05 wt% sodium dodecyl sulfate (SDS) was added, and the surface charge was adjusted to -45 mV by a high-speed shear emulsifier (10000 rpm × 10 min).

[0103] Step 5: Add 2.5 parts of nano zinc oxide (ZnO, photocatalytic grade, particle size 30 nm), 0.6 parts of thioxanthone photoinitiator (ITX) and the uniform liquid metal suspension in step 4 to the mixed matrix resin in sequence, and use a planetary mixer (revolution 30 rpm, rotation 1200 rpm) to disperse for 45 minutes under light-proof conditions to prepare a quick-drying modified road marking paint.

[0104] Comparative Example 1

[0105] The difference between this comparative example and Example 2 is that the modified gallium indium tin liquid metal in step 4 is not added, and the other operating steps are exactly the same.

[0106] Experimental example

[0107] The modified road marking coatings prepared in Examples 2, 3, 4 and the comparative example were subjected to a Taber abrasion test (500 revolutions, H18 grinding wheel). The compressive strength test of the coating was conducted using the GA / T298-2001 standard. The coating peeling test was conducted using a mechanical pull-off coating to test whether the coating was completely peeled off. The residual marking coating weight was tested in units of 10×50 cm, and the coating cross section was cut to test the distance H between the peeling layer and the substrate.

[0108] The specific experimental process is as follows:

[0109] First, pre-treat the substrate, clean and dry the asphalt or concrete road surface, and make sure it is free of oil, dirt and floating dust (water content ≤5%, pull-out strength ≥1.5MPa). Mill the old markings to a residual thickness of <0.2mm (to avoid shrinkage and cracking of the paint due to heat reflection). The construction temperature should be controlled at 5~40℃, and the relative humidity should be <85%; after rain, it should be dried naturally for more than 12 hours or heated by blast air until the dew point temperature difference is >3℃.

[0110] Then, high-pressure airless spraying was used for construction. Before construction, the coatings prepared in Examples 2, 3, 4 and the comparative example were degassed with a planetary mixer (500 rpm×10 min) and sieved (200 mesh filter); the viscosity of the coating was regulated by adding 0.5%~1.0% gas-phase SiO2 (Aerosil 200), and the viscosity of the coating was controlled to be 4500-6000 mPa·s (matching the shear thinning characteristics of the spraying) using a rotational viscometer (30°C).

[0111] Then use a high-pressure airless sprayer (select a pressure ratio of 45:1, a nozzle diameter of 0.43mm); set the spraying pressure to: 15-18MPa, spray distance 30-40cm, and gun speed 4-6m / min; spray wet film thickness: 1.2-1.5mm (dry film ≥0.9mm when the theoretical solid content is ≥75%).

[0112] After spraying, use UV-LED for curing. Control the wavelength to 365nm, the irradiation intensity to 100-120mW / cm², and the light curing time to 3-5s (when the glass transition temperature Tg jumps to above 35℃ detected by DSC, it is completely cured). Alternatively, dual-band optimization can be used: the short-wave band (315nm) is used in the front section to excite the ITX initiator, and the long-wave band (395nm) is used in the back section to activate the nano ZnO to catalyze the cross-linking reaction.

[0113] It should be noted that in order to enhance the reflective performance at night, 300-500μm glass beads (refractive index ≥1.5) can be spread simultaneously during spraying, and the embedding amount must be >0.6kg / m².

[0114] The performance comparison table of the two is shown in Table 1:

[0115] Table 1. Experimental example comparison table

[0116]

[0117] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a quick-drying modified road marking paint, characterized in that: The preparation method comprises: S100, weigh a high-solid acrylic epoxy resin, add ethyl acetate and propylene glycol methyl ether acetate mixed solution in portions, heat in a 45° C. water bath and stir for 30 minutes to prepare a first mixed solution, Adding a film-forming aid and a leveling agent to the first mixed solution in sequence, and dispersing at high speed for 15 minutes using a paddle stirrer to prepare a first mixed resin; S200, pretreating nano silicon dioxide and surface modifying flaky mica to prepare a composite functional filler; S300, adding the pretreated nano-silicon dioxide and the modified flaky mica to the first mixed resin three times, each time with an interval of 5 minutes, and dispersing with a high-speed disperser to prepare a second mixed resin; S400, dispersing the modified gallium indium tin liquid metal in a PMA / ethyl acetate mixed solvent with a volume ratio of 3:7, adding 0.05wt% sodium dodecyl sulfate, and adjusting the surface charge to -45mV by a high-speed shear emulsifier to prepare a modified gallium indium tin liquid metal suspension; S500, adding nano zinc oxide, thioxanthone photoinitiator and modified gallium indium tin liquid metal suspension to the second mixed resin in sequence, and dispersing them in a light-proof condition using a planetary mixer.

2. The method for preparing the quick-drying modified road marking paint according to claim 1, characterized in that: The mass ratio of the high solid acrylic epoxy resin to the mixed solution of ethyl acetate and propylene glycol methyl ether acetate in the first mixed solution is 2.13:

1. Volatile organic matter content ≤280g / L.

3. The method for preparing the quick-drying modified road marking paint according to claim 1, characterized in that: The film-forming aid is ethylene glycol butyl ether, and the leveling agent is polyether-modified siloxane.

4. The method for preparing the quick-drying modified road marking paint according to claim 1, characterized in that: The pretreatment of nano silicon dioxide comprises: The hydrophilic nano-silica and γ-aminopropyltriethoxysilane were added into anhydrous ethanol, treated with an ultrasonic stirrer for 30 minutes, filtered and the filtered material was activated in a vacuum drying oven.

5. The method for preparing the quick-drying modified road marking paint according to claim 1, characterized in that: The surface modification of flaky mica comprises: The mica powder was immersed in an acetone solution containing a titanate coupling agent, reacted with magnetic stirring at 60°C, centrifuged and dried for later use.

6. The method for preparing the quick-drying modified road marking paint according to claim 1, characterized in that: The step S300 further includes: maintaining the temperature ≤ 60° C. during the dispersion process, and sieving with 400 mesh after the dispersion is completed, so that the fineness of the prepared second mixed resin slurry is ≤ 25 μm.

7. The method for preparing the quick-drying modified road marking paint according to claim 1, characterized in that: The modified gallium indium tin liquid metal is a gallium indium tin eutectic liquid metal modified by a thiol-based silane coupling agent.

8. The method for preparing the quick-drying modified road marking paint according to claim 7, characterized in that: The thiol-silane coupling agent-modified gallium-indium-tin eutectic liquid metal is prepared by the following steps: S410, removing the Ga2O3 oxide layer on the surface of the gallium-indium-tin eutectic liquid metal by pickling, rinsing the reaction product with deionized water after the pickling, and placing the reactant in a vacuum drying oven to dry to remove free water on the surface; S420, mixing the gallium indium tin eutectic liquid metal after acid washing with ethylene glycol monobutyl ether, inputting the mixture into a microfluidic crusher, and performing a cyclic treatment for 3 times to obtain gallium indium tin eutectic liquid metal nanodroplets; S430, dissolving mercaptopropyltrimethoxysilane in an ethanol / water mixed solution with a volume ratio of 9:1, and adjusting the pH value of the solution to 4.5 with acetic acid to prepare a second mixed solution; S440, injecting the gallium indium tin eutectic liquid metal nano droplets into the second mixed solution, reacting in a 45° C. oil bath under nitrogen atmosphere protection for 2 hours, collecting the reaction product by centrifuge after the reaction is completed, and washing with anhydrous ethanol for 3 times to remove unreacted products, to prepare a thiol-silane coupling agent-modified gallium indium tin eutectic liquid metal, The molar ratio of the gallium-indium-tin eutectic liquid metal nanodroplets to the second mixed solution is 1:0.

8.

9. The method for preparing the quick-drying modified road marking paint according to claim 8, characterized in that: The pickling comprises immersing the gallium-indium-tin eutectic liquid metal in a 5wt% dilute hydrochloric acid solution, heating the dilute hydrochloric acid solution to 50° C., and reacting for 15 minutes using magnetic stirring; or, Immerse the gallium-indium-tin eutectic liquid metal in a 30wt% citric acid solution, heat the citric acid solution to 65°C, and react for 20 minutes using magnetic stirring; or, The gallium-indium-tin eutectic liquid metal was immersed in a 20wt% oxalic acid solution, the oxalic acid solution was heated to 65°C, and reacted for 30 minutes using magnetic stirring.

10. A quick-drying modified road marking paint, characterized in that: The quick-drying modified road marking paint is prepared according to the preparation method as described in any one of claims 1 to 9.

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