A quick-drying modified road marking paint and its preparation method

Abstract

The present invention discloses a quick-drying modified road marking paint and a preparation method thereof, belonging to the field of paint preparation. The preparation method includes: weighing high-solid-content acrylic epoxy resin, adding a mixed solution of ethyl acetate and propylene glycol methyl ether acetate in portions, and adding a film-forming aid and a leveling agent to prepare a first mixed resin; pretreating nano-silica and surface-modifying flaky mica to prepare a composite functional filler; adding the composite functional filler to the first mixed resin in three portions to prepare a second mixed resin; preparing a modified gallium indium tin liquid metal suspension; successively adding nano-zinc oxide, thioxanthone photoinitiator and the modified gallium indium tin liquid metal suspension to the second mixed resin, and dispersing under light-shielded conditions using a planetary stirrer. The road marking paint prepared by the present invention can effectively avoid the problem of marking pollution caused by electrostatic adsorption of dust.

Description

Technical Field

[0001] The present invention relates to the field of coatings, and particularly to a quick-drying modified road marking paint 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 abrasion resistance, serious static electricity accumulation, and poor self-cleaning ability, and it is difficult to meet the actual application requirements. Summary of the Invention

[0003] One of the purposes of the present invention is to provide a preparation method of a quick-drying modified road marking paint to solve the disadvantages of existing road marking paints such as slow drying, poor abrasion resistance, serious static electricity accumulation, and poor self-cleaning ability.

[0004] The present invention is achieved through the following technical solutions. A preparation method of a quick-drying modified road marking paint includes the following steps: S100. Weigh a high-solid acrylic epoxy resin, add it to a mixed solution of ethyl acetate and propylene glycol methyl ether acetate in portions, heat it in a 45°C water bath and stir for 30 minutes to prepare a first mixed solution. Add a film-forming aid and a leveling agent to the first mixed solution in sequence, and disperse it at high speed with a paddle stirrer for 15 minutes to prepare a first mixed resin; S200. Pretreat nano-silica and surface-modify flaky mica to prepare a composite functional filler; S300. Add the pretreated nano-silica and the modified flaky mica to the first mixed resin in three portions, with an interval of 5 minutes each time, and disperse it with a high-speed disperser to prepare a second mixed resin; S400. Disperse the modified gallium indium tin liquid metal in a PMA / ethyl acetate mixed solvent with a volume ratio of 3:7, add 0.05 wt% sodium dodecyl sulfate, and adjust the surface charge to -45 mV with a high-speed shear emulsifier to prepare a modified gallium indium tin liquid metal suspension; S500. Add nano-zinc oxide, thioxanthone photoinitiator, and the modified gallium indium tin liquid metal suspension to the second mixed resin in sequence, and disperse it with a planetary stirrer under light-shielded conditions.

[0005] Further, 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 compound content ≤ 280 g / L.

[0006] Further, the film-forming aid is ethylene glycol monobutyl ether, and the leveling agent is polyether-modified silicone.

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

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

[0009] Immersing mica powder into an acetone solution containing a titanate coupling agent, magnetically stirring and reacting at 60 °C, centrifuging and separating, and then air-drying for standby.

[0010] Further, step S300 also includes: maintaining the temperature ≤ 60 °C during the dispersion process, sieving through a 400-mesh sieve after the dispersion is completed, and the fineness of the slurry of the prepared second mixed resin ≤ 25 μm.

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

[0012] Further, the thiol-based silane coupling agent modified gallium-indium-tin eutectic liquid metal is prepared through 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 pickling is completed, and placing the reactant in a vacuum drying oven to dry and remove the surface free water after rinsing is completed; S420. Mixing the pickled gallium-indium-tin eutectic liquid metal with ethylene glycol monobutyl ether, inputting it into a microfluidic crusher, and circulating and processing 3 times to obtain gallium-indium-tin eutectic liquid metal nano-droplets; S430. Dissolving mercaptopropyltrimethoxysilane with an ethanol / water mixed solution with a volume ratio of 9:1, and adjusting the pH 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 an oil bath at 45 °C under a nitrogen atmosphere protection for 2 hours, after the reaction ends, collecting the reaction product by a centrifuge, and washing 3 times with absolute ethanol to remove the unreacted substances to prepare the thiol-based silane coupling agent modified gallium-indium-tin eutectic liquid metal, and the molar ratio of the gallium-indium-tin eutectic liquid metal nano-droplets to the second mixed solution is 1:0.8.

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

[0014] On the other hand, the present invention also 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 paint of the present invention uses a high-solid acrylic epoxy resin as the matrix resin, and additives such as photoinitiators and nano-zinc oxide are added, enabling the paint to have excellent quick-drying performance, high construction efficiency, shortening the road closure time, and reducing the impact on traffic.

[0017] It overcomes many defects existing in road marking paints and meets the actual application requirements.

[0018] 2. Composite functional fillers such as nano-silica and modified mica flakes are added to the paint of the present invention, endowing the paint with excellent wear resistance, prolonging the service life of road markings, and reducing the maintenance cost.

[0019] 3. Components such as nano-silica and nano-zinc oxide in the paint of the present invention have photocatalytic self-cleaning functions, endowing the paint with excellent self-cleaning performance, helping to maintain the cleanliness of the markings, and improving the recognition and night-time retroreflective performance of the markings.

[0020] 4. By introducing modified gallium-indium-tin liquid metal into the paint, the present invention has good electrical conductivity and antistatic performance, and can effectively avoid the problem of marking pollution caused by electrostatic adsorption of dust. After being 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 prolong the service life of the coating. And the modification by MPTMS makes the liquid metal have better compatibility, especially with the resin matrix or other materials, avoiding problems of phase separation and non-uniform dispersion, enabling the liquid metal paint to be well combined with the resin substrate, and providing 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, form a part of this application, and do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0022] Figure 1 It is a flowchart of the method provided by Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

[0024] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can 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 the methods and / or materials related to the said documents. In case of conflict with any incorporated document, the content of this specification shall prevail. Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, that is, they are intended to include but not limited to. Unless the context clearly indicates otherwise, the expressions "a" and "an" used herein include plural referents. It should be noted that "first", "second", etc. are only for convenience of description and easy distinction, and cannot be construed as indicating or implying relative importance. The term "about" used herein means a range of ±20% of the value following it. In some embodiments, the term "about" means a range of ±10% of the value following it. In some embodiments, the term "about" means a range of ±5% of the value following it.

[0025] Example 1

[0026] In this embodiment, a preparation method of 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 high solid content acrylic epoxy resin (solid content ≥ 75%, glass transition temperature Tg = 35°C), and gradually add ethyl acetate (industrial grade, purity 99%) and propylene glycol monomethyl ether acetate (PMA) under stirring conditions to prepare a first mixed solution. Keep the first mixed solution in a water bath at 45°C and stir at 600 rpm for 30 minutes until the solution is transparent and free of particles. Control the resin / solvent mass ratio to be 80:37.5 (2.13:1), and the volatile organic compound (VOC) content ≤ 280 g / L.

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

[0029] Step 2: Configure the composite functional filler. First, pretreat the nano-silica and surface-modify the flaky mica.

[0030] The pretreatment includes adding hydrophilic nano-silica and γ-aminopropyltriethoxysilane into absolute ethanol together, treating 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 into an acetone solution containing titanate coupling agent, magnetically stirring and reacting at 60 °C, centrifuging and separating, and then air-drying for standby.

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

[0033] Step 4: Premix 6 vol% modified gallium-indium-tin liquid metal and ammonium polyacrylate dispersant in ethylene glycol monobutyl ether, and treat with a three-roll mill for 3 times to obtain a uniform liquid metal suspension.

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

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

[0036] Pickle the gallium-indium-tin eutectic liquid metal to remove the oxide layer on the surface. The pickling can use citric acid, oxalic acid or dilute hydrochloric acid. Remove the Ga2O3 oxide layer on the surface of the gallium-indium-tin eutectic liquid metal through pickling.

[0037] After the washing is completed, rinse the reaction product with deionized water. After the rinsing is completed, place the reactant in a vacuum drying oven to dry and remove the surface free water.

[0038] 2) Mix the pickled gallium-indium-tin eutectic liquid metal with ethylene glycol monobutyl ether, input it into a microfluidic crusher, and circulate and process 3 times to obtain gallium-indium-tin eutectic liquid metal nano-droplets.

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

[0040] Inject the gallium-indium-tin eutectic liquid metal nano-droplets into the hydrolyzed mercaptopropyltrimethoxysilane solution. The molar ratio of the gallium-indium-tin eutectic liquid metal nano-droplets to the mercaptopropyltrimethoxysilane solution is 1:0.8. React in a 45 °C oil bath for 2 hours under the protection of a nitrogen atmosphere, with continuous stirring during the period.

[0041] After the reaction is completed, the reaction product is collected by a centrifuge and washed three times with absolute ethanol to remove unreacted substances, obtaining a thiol-functionalized silane-coupled gallium-indium-tin eutectic liquid metal.

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

[0043] Step 5: Nano-zinc oxide, thioxanthone photoinitiator, and the homogeneous liquid-modified gallium-indium-tin eutectic liquid metal suspension in Step 4 are successively added to the second mixed resin, and dispersed using a planetary mixer under light-shielded conditions to prepare a quick-drying modified road marking paint.

[0044] Example 2

[0045] Step 1: Prepare the matrix 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 conditions, maintain a water bath heating at 50 °C, 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 silicone as a leveling agent are successively added to the prepared resin-solvent mixed solution, and dispersed at a high speed of 1500 rpm for 15 minutes using a paddle stirrer to prepare the matrix resin.

[0047] Step 2: Prepare the composite functional filler, including pretreatment of nano-silica and surface modification of 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 part of γ-aminopropyltriethoxysilane (KH550) to 20 parts of absolute ethanol, treating with an ultrasonic stirrer (power 600 W, frequency 28 kHz) for 30 minutes, and then activating in an 80 °C vacuum drying oven for 2 hours.

[0049] The surface modification of flaky mica includes: immersing 5 parts of mica powder (aspect ratio > 80) in an acetone solution containing 1.5 parts of titanate coupling agent (NDZ-201), magnetically stirring and reacting at 60 °C for 1 hour, centrifuging and separating, and then drying for standby.

[0050] Step 3: Add the activated nano-silica and modified mica flakes prepared in Step 2 into the matrix resin prepared in Step 1 in three portions, with a 5-minute interval between each addition. Disperse for 40 minutes using a high-speed disperser (rotation speed 2500 rpm, blade diameter 50 mm), and maintain the temperature ≤ 60 °C during the process. Sieve (400 mesh) to remove undispersed aggregates, and measure the slurry fineness ≤ 25 μm (Hegman blade gauge) to obtain the mixed matrix resin.

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

[0052] Specifically, the modified gallium-indium-tin liquid metal in this example is prepared through the following steps:

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

[0054] First, pickle the gallium-indium-tin eutectic liquid metal to remove the surface oxide layer. In this example, immerse 100 g of gallium-indium-tin eutectic liquid metal (Ga62.5In21.5Sn16, melting point 10.8 °C) into a 5 wt% dilute hydrochloric acid (HCl) solution, heat the dilute hydrochloric acid solution to 50 °C, and use magnetic stirring to react for 15 minutes to remove the surface Ga2O3 oxide layer by acid etching.

[0055] After pickling, rinse the reaction product 3 times with deionized water, and then treat it in a vacuum drying oven (temperature 30 °C / -0.1 MPa) for 20 minutes to remove surface free water.

[0056] 2) Mix the pickled LM with 200 ml of ethylene glycol monobutyl ether, input it into a microfluidic crusher (shearing pressure 150 MPa, channel diameter 50 μm), and circulate and process it 3 times to obtain LM nano-droplets with a particle size D50 = 100 nm.

[0057] It should be noted that in this step, the thickness of the oxide layer can be reduced from 80 nm to < 2 nm through treatment with dilute hydrochloric acid (confirmed by XPS characterization); use diethylene glycol monobutyl ether as a co-solvent to ensure compatibility with the resin matrix in 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 = 4.5 using acetic acid, and complete hydrolysis by magnetic stirring at 35 °C for 1 hour.

[0059] Slowly inject LM nanodroplets into the hydrolyzed MPTMS solution (molar ratio of LM:MPTMS = 1:0.8), introduce nitrogen for protection, and react in an oil bath at 45 °C for 2 hours, with continuous stirring at 800 rpm during this period.

[0060] After the reaction, collect the modified LM (MPTMS@LM) by centrifugation (12000 rpm × 15 min), and wash it 3 times with anhydrous ethanol to remove the unreacted substances, thus preparing the thiol-functionalized 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 groups hydrolyze to form a Si-O-Si network coating LM; realizing dual protection of physical barrier and chemical passivation (preventing secondary oxidation).

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

[0063] Verification of particle size stability: Monitor the suspension using a dynamic light scattering instrument (DLS) to ensure that the particle size increase is ≤ 15% after 7 days of storage (an increase from D50 = 180 nm to 207 nm is considered qualified).

[0064] It should be noted that: the anionic property 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 break the formulation balance.

[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 homogeneous liquid metal suspension in step 4 to the mixed matrix resin in sequence, and disperse them for 45 minutes under light-shielded conditions using a planetary mixer (revolution 30 rpm, rotation 1200 rpm) to prepare the fast-drying modified road marking paint.

[0066] It should be noted that in this embodiment, after modifying the gallium-indium-tin eutectic liquid metal with a thiol-based silane coupling agent, it can not only form a strong interfacial bond with the resin matrix, but also significantly improve the curing efficiency of the coating, thus achieving the quick-drying effect. The 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 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 interior of the coating through uniformly dispersed heat paths, which can significantly shorten the activation time of the resin cross-linking reaction. At the same time, during the solvent evaporation stage, the surface modification layer of the LM nano-droplets can stabilize the Pickering emulsion structure, ensuring that solvent molecules (such as xylene and ethyl acetate) escape quickly through nano-scale channels, thereby increasing the solvent evaporation rate. And by uniformly mixing the modified LM in the resin matrix, a heat conduction network of LM is formed in the coating layer, thus promoting the uniform diffusion of heat from the surface to the inside, shortening the glass transition time of the resin.

[0067] Example 3

[0068] Step 1: Prepare the matrix resin. Weigh 90 parts of high solid content acrylic epoxy resin. Under stirring conditions, gradually add 35 parts of ethyl acetate (industrial grade, purity 99%) and 10 parts of propylene glycol methyl ether acetate (PMA). Maintain 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, add 6 parts of ethylene glycol butyl ether as a film-forming aid and 3 parts of polyether-modified silicone as a leveling agent to the prepared resin-solvent mixed solution in sequence. Use a paddle stirrer to disperse at a high speed of 1000 rpm for 20 minutes to prepare the matrix resin.

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

[0071] Specifically, the pre-treatment 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) to 25 parts of absolute ethanol. Treat with an ultrasonic stirrer (power 600 W, frequency 28 kHz) for 40 minutes, and then activate in a vacuum drying oven at 85°C for 1.5 hours.

[0072] The surface modification of flaky mica includes: Immerse 10 parts of mica powder (aspect ratio > 80) in an acetone solution containing 3 parts of titanate coupling agent (NDZ-201), and stir magnetically at 60°C for 1 hour. After centrifugal separation, air dry for later use.

[0073] Step 3: Add the activated nano-silica and modified mica flakes prepared in Step 2 into the matrix resin prepared in Step 1 in three portions, with a 5-minute interval between each addition. Disperse for 40 minutes using a high-speed disperser (rotation speed 2500 rpm, blade diameter 50 mm), and maintain the temperature ≤ 60 °C during the process. Screen (400 mesh) to remove undispersed aggregates, measure the fineness of the slurry ≤ 25 μm, and obtain the mixed matrix resin.

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

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

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

[0077] First, perform pickling on the gallium indium tin eutectic liquid metal to remove the surface oxide layer. In this example, immerse 100 g of gallium indium tin eutectic liquid metal (Ga62.5In21.5Sn16, melting point 10.8 °C) into a 30 wt% citric acid solution, heat the citric acid solution to 65 °C, and use magnetic stirring to react for 20 minutes to remove the surface Ga2O3 oxide layer by acid etching.

[0078] After pickling, rinse the reaction product 3 times with deionized water, and then treat it in a vacuum drying oven (temperature 30 °C / -0.1 MPa) for 20 minutes to remove surface free water.

[0079] 2) Mix the pickled LM with 200 ml of ethylene glycol monobutyl ether, input it into a microfluidic crusher (shearing pressure 150 MPa, channel diameter 50 μm), and circulate and process 3 times to obtain LM nano-droplets with a particle size D50 = 150 nm.

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

[0081] Slowly inject the LM nano-droplets into the hydrolyzed MPTMS solution (molar ratio of LM:MPTMS = 1:0.8), introduce nitrogen protection, and react in an oil bath at 45 °C for 2 hours, with continuous stirring at 800 rpm during this period.

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

[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 generate a Si-O-Si network to coat LM; realizing double protection of physical barrier and chemical passivation (preventing 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: 2.5 parts of nano-zinc oxide (ZnO, photocatalytic grade, particle size 30 nm), 0.6 part of thioxanthone photoinitiator (ITX) and the homogeneous liquid metal suspension in Step 4 were successively added to the mixed matrix resin, and dispersed for 45 minutes under dark conditions using a planetary mixer (revolution 30 rpm, rotation 1200 rpm) to prepare a quick-drying modified road marking paint.

[0086] Example 4

[0087] Step 1: Prepare the matrix resin. Weigh 70 parts of high-solid acrylic epoxy resin, and gradually add 25 parts of ethyl acetate (industrial grade, purity 99%) and 15 parts of propylene glycol methyl ether acetate (PMA) under stirring conditions. Maintain 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 silicone as a leveling agent were successively added to the prepared resin-solvent mixed solution, and dispersed at high speed for 15 minutes at 1000 rpm using a paddle stirrer to prepare the matrix resin.

[0089] Step 2: Prepare the composite functional filler, including pretreatment of nano-silica and surface modification of 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 part of γ-aminopropyltriethoxysilane to 20 parts of absolute 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 (aspect ratio > 80) into an acetone solution containing 1.5 parts of titanate coupling agent (NDZ-201), magnetically stirring and reacting at 60 °C for 1 hour, centrifuging and separating, and then air-drying for standby.

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

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

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

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

[0096] First, perform acid pickling on the gallium indium tin eutectic liquid metal to remove the surface oxide layer. In this example, immerse 100 g of gallium indium tin eutectic liquid metal (Ga62.5In21.5Sn16, melting point 10.8 °C) into a 20 wt% oxalic acid solution, heat the oxalic acid solution to 65 °C, use magnetic stirring to react for 30 minutes, and remove the surface Ga2O3 oxide layer by acid etching.

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

[0098] 2) Mix the pickled LM with 200 ml of ethylene glycol monobutyl ether, input it into a microfluidic crusher (shearing pressure 150 MPa, channel diameter 50 μm), and circulate and process 3 times to obtain LM nano-droplets with a particle size D50 = 180 nm.

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

[0100] Slowly inject LM nano-droplets into the hydrolyzed MPTMS solution (molar ratio of LM:MPTMS = 1:0.8), introduce nitrogen protection, and react in an oil bath at 45 °C for 2 hours, with continuous stirring at 800 rpm during this period.

[0101] After the reaction, collect the modified LM (MPTMS@LM) by centrifugation (12000 rpm × 15 min), and wash it 3 times with absolute ethanol to remove unreacted substances, thus preparing the thiol-based silane coupling agent modified gallium-indium-tin eutectic liquid metal (modified MPTMS@LM).

[0102] 4) Redisperse the modified MPTMS@LM in a mixed solvent of PMA / ethyl acetate (volume ratio 3:7), add 0.05 wt% sodium dodecyl sulfate (SDS), and adjust the surface charge to -45 mV through 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 part of thioxanthone photoinitiator (ITX) and the uniform liquid metal suspension in Step 4 to the mixed matrix resin in sequence, and disperse them for 45 minutes under light-shielded conditions using a planetary stirrer (revolution 30 rpm, rotation 1200 rpm) to prepare the 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 rest of the operation steps are exactly the same.

[0106] Experimental Example

[0107] Conduct Taber wear (500 revolutions, H18 grinding wheel) experiments on the modified road marking paints prepared in Examples 2, 3, 4 and the comparative example. The compressive strength test of the paint is carried out according to the standard of GA / T298 - 2001; the coating peeling test uses mechanical pulling to peel off the coating, tests whether the coating peeling is complete, and tests the residual marking paint weight in units of 10 × 50 cm, intercepts the cross-section of the coating, and tests the distance H between the peeled 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, without oil stains and floating dust (moisture content ≤ 5%, pull-out strength ≥ 1.5 MPa). Milling the old marking to a residual thickness < 0.2 mm (to avoid coating shrinkage and cracking caused by thermal reflection). Control the construction temperature at 5 - 40 °C, relative humidity < 85%; after rain, it needs to be naturally dried for more than 12 hours or heated by blowing to a dew point temperature difference > 3 °C.

[0110] Then, high-pressure airless spraying construction is used. Before construction, the coatings prepared in Examples 2, 3, 4 and the comparative example are defoamed with a planetary mixer (500 rpm × 10 min) and sieved through a 200-mesh filter screen; and the viscosity of the coatings is adjusted. 0.5% - 1.0% fumed SiO2 (Aerosil 200) is added, and a rotational viscometer (30 °C) is used to control the coating viscosity to be 4500 - 6000 mPa·s (matching the spray shear thinning characteristics).

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

[0112] After spraying is completed, UV-LED is used for curing. The wavelength is controlled at 365 nm, the irradiation intensity is 100 - 120 mW / cm², and the photocuring time is 3 - 5 s (when the glass transition temperature Tg detected by DSC jumps to above 35 °C, it is considered completely cured). Or dual-band optimization can be used: the short wavelength band (315 nm) is used in the front section to excite the ITX initiator, and the long wavelength band (395 nm) is used in the rear section to activate the nano-ZnO catalytic cross-linking reaction.

[0113] It should be noted that in order to enhance the night-time retroreflective performance, 300 - 500 μm glass microspheres (refractive index ≥ 1.5) can also be synchronously spread during spraying, and the embedding amount needs to be > 0.6 kg / m².

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

[0115] Table 1. Comparison Table of Experimental Examples

[0116]

[0117] The specific embodiments described above have further elaborated on the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of a quick-drying modified road marking paint, characterized in that The preparation method includes: S100. Weigh high-solid acrylic epoxy resin, add it to the mixed solution of ethyl acetate and propylene glycol methyl ether acetate in portions, heat it in a 45°C water bath and stir for 30 minutes to obtain a first mixed solution. Add a film-forming aid and a leveling agent to the first mixed solution in sequence, and disperse it at high speed with a paddle stirrer for 15 minutes to obtain a first mixed resin. S200. Pretreat nano-silica and modify the surface of flaky mica to obtain a composite functional filler. S300. Add the pretreated nano-silica and the modified flaky mica to the first mixed resin in three portions at intervals of 5 minutes each, and disperse them with a high-speed disperser to obtain a second mixed resin. S400. Disperse the modified gallium-indium-tin liquid metal in a PMA / ethyl acetate mixed solvent with a volume ratio of 3:7, add 0.05 wt% sodium dodecyl sulfate, and adjust the surface charge to -45 mV with a high-speed shear emulsifier to obtain a modified gallium-indium-tin liquid metal suspension. S500. Add nano-zinc oxide, thioxanthone photoinitiator and the modified gallium-indium-tin liquid metal suspension to the second mixed resin in sequence, and disperse them with a planetary mixer under light-shielded conditions. The modified gallium-indium-tin liquid metal is a thiol-based silane coupling agent modified gallium-indium-tin eutectic liquid metal. The thiol-based silane coupling agent modified gallium-indium-tin eutectic liquid metal is prepared through the following steps: S410. Remove the Ga2O3 oxide layer on the surface of the gallium-indium-tin eutectic liquid metal by pickling. After pickling, rinse the reaction product with deionized water. After rinsing, place the reactant in a vacuum drying oven to dry and remove the surface free water. S420. Mix the pickled gallium-indium-tin eutectic liquid metal with ethylene glycol monobutyl ether, input it into a microfluidic crusher, and circulate it 3 times to obtain gallium-indium-tin eutectic liquid metal nano-droplets. S430. Dissolve mercaptopropyltrimethoxysilane with an ethanol / water mixed solution with a volume ratio of 9:1, and adjust the pH of the solution to 4.5 with acetic acid to obtain a second mixed solution. S440. Inject the gallium-indium-tin eutectic liquid metal nano-droplets into the second mixed solution, react in a 45°C oil bath under a nitrogen atmosphere for 2 hours. After the reaction, collect the reaction product by centrifugation, and wash it 3 times with absolute ethanol to remove the unreacted substances to obtain the thiol-based silane coupling agent modified gallium-indium-tin eutectic liquid metal. The molar ratio of the gallium-indium-tin eutectic liquid metal nano-droplets to the second mixed solution is 1:0.

8.

2. The preparation method of 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. The volatile organic compound content ≤ 280 g / L.

3. The preparation method of the quick-drying modified road marking paint according to claim 1, characterized in that, The film-forming aid is ethylene glycol monobutyl ether, and the leveling agent is polyether-modified silicone.

4. The preparation method of the quick-drying modified road marking paint according to claim 1, characterized in that, The pretreatment of the nano-silica includes: Add hydrophilic nano-silica and γ-aminopropyltriethoxysilane to absolute ethanol together, treat it with an ultrasonic stirrer for 30 minutes, then filter it and place the filtered material in a vacuum drying oven for activation.

5. The preparation method of the quick-drying modified road marking paint according to claim 1, characterized in that, The surface modification of the flaky mica includes: Immerse mica powder in an acetone solution containing a titanate coupling agent, magnetically stir and react at 60 °C, and after centrifugal separation, air-dry for standby.

6. The preparation method of the quick-drying modified road marking paint according to claim 1, wherein The step S300 further includes: maintaining the temperature ≤ 60 °C during the dispersion process, and using a 400-mesh sieve after the dispersion is completed. The fineness of the slurry of the prepared second mixed resin is ≤ 25 μm.

7. The preparation method of the quick-drying modified road marking paint according to claim 1, characterized in that, 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 magnetically stirring and reacting for 15 min; or, Immerse the gallium-indium-tin eutectic liquid metal in a 30wt% citric acid solution, heating the citric acid solution to 65 °C, and magnetically stirring and reacting for 20 min; or, Immerse the gallium-indium-tin eutectic liquid metal in a 20wt% oxalic acid solution, heating the oxalic acid solution to 65 °C, and magnetically stirring and reacting for 30 min.

8. A quick-drying modified road marking paint, characterized in that, The quick-drying modified road marking paint is prepared according to the preparation method described in any one of claims 1 to 7.

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