Water-based outdoor asphalt pavement color-changing coating and preparation method thereof

Abstract

The application discloses a kind of water-based outdoor asphalt pavement color-changing coating and preparation method thereof, belong to water-based paint technical field.The formula composition of the coating includes: 30-50 parts of self-crosslinking type elastic acrylate copolymer emulsion, 10-30 parts of inorganic nano-modified acrylic emulsion, 20-25 parts of color-changing pigment, 0.3-0.8 parts of dispersing agent, 0.3-0.8 parts of base material wetting agent, 0.1-0.3 parts of defoaming agent, 0.2-0.5 parts of leveling agent, 0.5-1.2 parts of thickening agent, 1-5 parts of LH additive, 0.1-0.5 parts of pH regulator, 10-15 parts of deionized water.The beneficial effect: the present application is by the specific proportion of self-crosslinking type elastic acrylate copolymer emulsion, inorganic nano-modified acrylic emulsion, color-changing pigment, dispersing agent, base material wetting agent, defoaming agent, leveling agent, thickening agent, LH additive, pH regulator and deionized water are mixed, after specific preparation procedure, obtain a kind of water-based outdoor asphalt pavement color-changing coating, improve weather resistance, water resistance, wear resistance and acid and alkali resistance.

Description

Technical Field

[0001] This invention relates to the field of water-based coatings technology, specifically to a water-based outdoor asphalt pavement color-changing coating and its preparation method. Background Technology

[0002] Since the 20th century, asphalt has been widely used as a paving material. Today, asphalt pavements are used for highways, city streets, sidewalks, non-motorized vehicle lanes, and park greenways.

[0003] Colored asphalt pavement is commonly used for sidewalks, non-motorized vehicle lanes, and park greenways. This improves the monotony of ordinary black asphalt pavement and allows it to blend harmoniously with surrounding buildings and landscapes. It beautifies the city, guides traffic, and reflects the characteristics and style of a country or city, enhancing the overall image and function of the city and showcasing the grandeur and charm of a modern metropolis.

[0004] Traditional colored asphalt processes primarily use light-colored asphalt binders, supplemented with various pigments for color modification. However, in practical applications, this type of colored asphalt pavement is prone to fading after exposure to wind and sun, significantly affecting its appearance and lifespan.

[0005] For example, patent CN115124926 A discloses a coating for outdoor asphalt color modification and its preparation method. This invention uses emulsified asphalt as raw material, and its water-based formulation is environmentally friendly. The addition of water-based epoxy resin can improve the corrosion resistance and wear resistance of the road surface; however, epoxy resin has poor weather resistance and is not suitable for outdoor use. Furthermore, the two-component design results in high cost and inconvenient construction.

[0006] Conventional water-based coatings have a drawback: poor applicability in low-temperature, high-humidity environments. They cannot be applied in winter when temperatures drop below 5°C, and their drying performance is significantly reduced during the rainy season when humidity is high. Asphalt pavement color-changing coatings are typically applied outdoors, requiring fast application and the ability to withstand low temperatures and sudden weather changes. Summary of the Invention

[0007] The technical problem to be solved by this invention is how to solve the problems of poor water resistance, weather resistance and wear resistance of existing outdoor asphalt pavement color-changing coatings.

[0008] The present invention solves the above-mentioned technical problems through the following technical means:

[0009] The first aspect of this invention provides a water-based outdoor asphalt pavement color-changing coating, the formulation comprising, by weight parts: 30-50 parts of self-crosslinking elastic acrylic copolymer emulsion, 10-30 parts of inorganic nano-modified acrylic emulsion, 20-25 parts of color-changing pigment, 0.3-0.8 parts of dispersant, 0.3-0.8 parts of substrate wetting agent, 0.1-0.3 parts of defoamer, 0.2-0.5 parts of leveling agent, 0.5-1.2 parts of thickener, 1-5 parts of LH additive, 0.1-0.5 parts of pH adjuster, and 10-15 parts of deionized water.

[0010] Beneficial Effects: This invention combines a specific ratio of self-crosslinking elastic acrylate copolymer emulsion, inorganic nano-modified acrylic emulsion, color-changing pigment, dispersant, substrate wetting agent, defoamer, leveling agent, thickener, LH additive, pH adjuster, and deionized water to prepare a water-based outdoor asphalt pavement color-changing coating. This coating exhibits excellent low-temperature film-forming properties, drying performance, initial water resistance, weather resistance, and abrasion resistance. It is low-cost, single-component, and easy to apply, making it suitable for the renovation and maintenance of faded colored asphalt pavements and for color changing of black asphalt pavements.

[0011] Self-crosslinking elastic acrylate copolymer emulsion is an anionic emulsion copolymerized from acrylate monomers. It features small particle size and moderate viscosity. Due to its good compatibility with pigments and excellent pigment adhesion, it can hold a high amount of pigment. Because of its low glass transition temperature and moderate viscosity, it maintains excellent elasticity and good fullness even at low temperatures. Furthermore, its minimum film-forming temperature is below 0°C, ensuring smooth application in low winter temperatures without affecting film formation.

[0012] Inorganic nano-modified acrylic emulsions are polymerized from inorganic nanomaterials and acrylate monomers, exhibiting inorganic-organic hybrid characteristics. The introduction of inorganic materials enhances weather resistance and abrasion resistance.

[0013] By blending the two materials, the mixed emulsion retains flexibility even at -10°C, increasing the feasibility of low-temperature application in winter. The blended emulsion has lower surface tension, resulting in better wetting and penetration on asphalt pavements, ensuring adhesion between the color-changing coating and the asphalt surface. Through complementary advantages, the blended emulsion improves the water resistance, acid and alkali resistance, weather resistance, and abrasion resistance of the paint film.

[0014] Preferably, the self-crosslinking elastic acrylate copolymer emulsion is of type XL-CA.

[0015] Preferably, the inorganic nano-modified acrylic emulsion is of model TJG-6630.

[0016] Preferably, the color-changing pigment includes, but is not limited to, one or more of iron oxide red, titanium dioxide, and organic yellow pigment.

[0017] Preferably, the dispersant is one or a mixture of two of BYK-190, BYK-2012, and EFKA-4560.

[0018] Beneficial effects: It has excellent wetting and dispersing properties for inorganic and organic pigments, ensures stable storage without aggregation, and is unaffected by pH value.

[0019] Preferably, the substrate wetting agent is SINPOLS PAG-30 or TEGO 4100.

[0020] Beneficial effects: It has extremely low dynamic surface tension, eliminates microbubbles and oil shrinkage, does not affect recoating, and does not cause foam instability.

[0021] Preferably, the defoamer is BYK-093 or BYK-024.

[0022] Beneficial effects: It has good defoaming properties, good compatibility, and is not prone to causing oil leakage due to pinholes.

[0023] Preferably, the leveling agent is SN-4034 or BYK-333.

[0024] Beneficial effects: Excellent compatibility, provides good leveling properties, and improves substrate wettability and surface smoothness.

[0025] Preferably, the thickener is one or a mixture of two of AP-660, RW-8W, and Gel 0620.

[0026] Beneficial effects: Provides low-shear and high-shear thickening effects, improves viscosity stability and enhances rheological properties.

[0027] Preferably, the pH adjuster is APM-95 or SN-9730.

[0028] Beneficial effects: Stabilizes the pH of the system, has a low odor, and is highly effective.

[0029] Preferably, the LH additive is a mixture of ethylene glycol butyl ether, diethylene glycol butyl ether, and propylene glycol in a weight ratio of 1:3:1.

[0030] Beneficial effects: When ethylene glycol butyl ether, diethylene glycol butyl ether and propylene glycol are mixed in a specific ratio, they can provide an effective film-forming effect and ensure that the system remains stable and undamaged at lower temperatures.

[0031] A second aspect of the present invention provides a method for preparing the above-mentioned water-based outdoor asphalt pavement color-changing coating, comprising the following steps: feeding the raw materials according to the mass proportions of the above-mentioned materials:

[0032] (1) Add inorganic nano-modified acrylic emulsion into the mixing tank, and under stirring, add dispersant, substrate wetting agent, defoamer, color-changing pigment and a part of pH adjuster, stir evenly, wash the mixing tank with a part of deionized water, and then proceed to the next process.

[0033] (2) The raw material from step (1) is sucked into the grinding mill and ground to a fineness of ≤40μm; the grinding mill is cleaned with the remaining deionized water and then proceeded to the next process.

[0034] (3) Transfer the raw materials from step (2) into the paint mixing tank, and add the self-crosslinking elastic acrylate copolymer emulsion, LH additive, and leveling agent while stirring, and stir evenly.

[0035] (4) Add thickener to adjust the viscosity to between 65-85 KU, and use the remaining pH adjuster to adjust the pH to between 8-9. Stir evenly, filter, and obtain water-based outdoor asphalt pavement color-changing coating.

[0036] The advantages of this invention are:

[0037] (1) This invention obtains a water-based outdoor asphalt pavement color-changing coating by mixing a specific proportion of self-crosslinking elastic acrylic copolymer emulsion, inorganic nano-modified acrylic emulsion, color-changing pigment, dispersant, substrate wetting agent, defoamer, leveling agent, thickener, LH additive, pH adjuster and deionized water through specific preparation steps, thereby improving weather resistance, water resistance, wear resistance and acid and alkali resistance.

[0038] (2) The inorganic nano-modified acrylic emulsion selected in this invention has excellent mechanical stability (2500rpm, 0.5hr), can be directly used in grinding and slurrying, reduce the use of deionized water, increase the solid content of the product, improve the drying rate of the paint film, and the inorganic nano-modified acrylic emulsion can improve weather resistance and wear resistance.

[0039] (3) This invention uses a combination of dispersants and thickeners with excellent dispersing properties, which can provide good stability to the system and ensure that no water separation, stratification, or precipitation occurs during storage at a low viscosity. At a low viscosity, the product system does not require dilution with water during application, which can improve the drying rate of the paint film and ensure good leveling of the paint film, achieving the ideal paint surface effect.

[0040] (4) The preparation method of the present invention is simple, the dispersion medium in the preparation process is deionized water, the production and transportation process is safe and environmentally friendly, the content of volatile organic compounds (VOC) in the product is extremely low, the odor is small, which is beneficial to environmental protection and the health of construction workers.

[0041] (5) This invention cleverly combines two types of self-crosslinking elastic acrylic copolymer emulsion and inorganic nano-modified acrylic emulsion in a certain proportion, which greatly improves the performance of the product. It is suitable for outdoor construction, and the paint film has good wear resistance, weather resistance, acid and alkali resistance, and water resistance. It has good adhesion to asphalt surfaces and is a good choice for asphalt pavement color changing and maintenance renovation.

[0042] (6) The present invention provides a water-based outdoor asphalt pavement color-changing coating, which adopts a single-component design, is a room-temperature self-drying water-based coating, has low formulation cost, high product cost performance, and is easy to construct. It is suitable for renovation and maintenance of large-area colored asphalt pavement after fading, as well as for color-changing of black asphalt pavement. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Unless otherwise specified, all experimental materials and reagents used in the following examples are commercially available.

[0045] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0046] In this invention, BYK-190, BYK-2012, BYK-093, BYK-024, and BYK-333 are products of BYK Chemical AG (Germany); EFKA-4560 is a product of Efka AG (Germany); SN-4034 and SN-9730 are products of Shanghai Shenzhu Chemical Technology Co., Ltd.; SINPOLS PAG-30 is a product of Xipusen New Materials (Ningbo) Co., Ltd.; TEGO 4100 is a product of Yingchuang Digo Chemical Co., Ltd. (Germany); AP-660 is a product of Shanghai Tianyu Chemical Technology Co., Ltd.; RW-8W is purchased from Rohm and Haas Corporation (USA); and Gel 0620 is purchased from OMG Corporation (USA).

[0047] The self-crosslinking elastic acrylate copolymer emulsion, inorganic nano-modified acrylic emulsion, color-changing pigment, dispersant, substrate wetting agent, defoamer, leveling agent, thickener, LH additive, and pH adjuster in the following examples are all existing technologies.

[0048] Example 1:

[0049] A water-based outdoor asphalt pavement color-changing coating, by weight, comprises the following raw materials: 50 parts of self-crosslinking elastic acrylic copolymer emulsion (model XL-CA), 10 parts of inorganic nano-modified acrylic emulsion (model TJG-6630), 20 parts of color-changing pigment (iron oxide red), 0.6 parts of BYK-2012 dispersant, 0.4 parts of TEGO 4100 substrate wetting agent, 0.1 parts of BYK-024 defoamer, 0.3 parts of BYK-333 leveling agent, 1.2 parts of thickener, 3 parts of LH additive, 0.4 parts of APM-95 pH adjuster, and 14 parts of deionized water.

[0050] In this embodiment, AP-660 and Gel 0620 are used together as thickeners in a mass ratio of 1:2. AP-660 thickener is diluted to a 50% concentration using deionized water, and Gel 0620 thickener is diluted to a 50% concentration using ethylene glycol butyl ether. The LH additive is a mixture of ethylene glycol butyl ether, diethylene glycol butyl ether, and propylene glycol in a weight ratio of 1:3:1.

[0051] The present invention provides a method for preparing a water-based outdoor asphalt pavement color-changing coating, comprising the following steps:

[0052] Add the ingredients according to the mass proportions of the above-mentioned raw materials:

[0053] (1) Add inorganic nano-modified acrylic emulsion to the mixing tank, turn on the stirrer, and stir at a speed of 400r / min-600r / min. While stirring, add dispersant, substrate wetting agent, defoamer, color-changing pigment, and pH adjuster (60% of the formula amount) in sequence. After the addition is complete, increase the speed to 800r / min-1000r / min and disperse at this speed for 30 minutes. Clean the mixing tank with half the amount of deionized water in the formula and proceed to the next process.

[0054] (2) Use a diaphragm pump to draw the material into the sand mill, start the sand mill to circulate and grind, and control the temperature of the sand mill outlet at ≤35℃. Check the fineness after each grinding cycle until the fineness is ≤40μm. Use the other half of the deionized water to clean the sand mill and proceed to the next process.

[0055] (3) After the color paste has passed the fineness test, it is transferred to the paint mixing tank. Stirring is started. At a stirring speed of 400r / min-600r / min, self-crosslinking elastic acrylate copolymer emulsion, LH additive, and leveling agent are added in sequence. After the addition is completed, stirring is continued at the same speed for 15min.

[0056] (4) Add thickeners Gel 0620 and AP-660, adjust the viscosity to 75-85 KU, and adjust the pH value to 8-9 with pH adjuster. After stirring evenly, filter and the obtained filtrate is water-based outdoor asphalt pavement color-changing coating.

[0057] Example 2:

[0058] A water-based outdoor asphalt pavement color-changing coating, by weight, comprises the following raw materials: 40 parts of self-crosslinking elastic acrylic copolymer emulsion (model XL-CA), 20 parts of inorganic nano-modified acrylic emulsion (model TJG-6630), 25 parts of color-changing pigment (organic yellow), 0.6 parts of BYK-2012 dispersant, 0.4 parts of TEGO 4100 substrate wetting agent, 0.1 parts of BYK-024 defoamer, 0.3 parts of BYK-333 leveling agent, 0.8 parts of thickener, 4 parts of LH additive, 0.4 parts of APM-95 pH adjuster, and 10 parts of deionized water.

[0059] In this embodiment, AP-660 and RW-8W are used together as thickeners in a mass ratio of 1:2. AP-660 thickener is diluted to a 50% concentration using deionized water, and RW-8W thickener is diluted to a 50% concentration using ethylene glycol butyl ether. The LH additive is a mixture of ethylene glycol butyl ether, diethylene glycol butyl ether, and propylene glycol in a weight ratio of 1:3:1.

[0060] The present invention provides a method for preparing a water-based outdoor asphalt pavement color-changing coating, comprising the following steps:

[0061] Add the ingredients according to the mass proportions of the above-mentioned raw materials:

[0062] (1) Add inorganic nano-modified acrylic emulsion to the mixing tank, turn on the stirrer, and stir at a speed of 400r / min-600r / min. While stirring, add dispersant, substrate wetting agent, defoamer, color-changing pigment, and pH adjuster (60% of the formula amount) in sequence. After the addition is complete, increase the speed to 800r / min-1000r / min and disperse at this speed for 30 minutes. Clean the mixing tank with half the amount of deionized water in the formula and proceed to the next process.

[0063] (2) Use a diaphragm pump to draw the material into the sand mill, start the sand mill to circulate and grind, and control the temperature of the sand mill outlet at ≤35℃. Check the fineness after each grinding cycle until the fineness is ≤40μm. Use the other half of the deionized water to clean the sand mill and proceed to the next process.

[0064] (3) After the color paste has passed the fineness test, it is transferred to the paint mixing tank. Stirring is started. At a stirring speed of 400r / min-600r / min, self-crosslinking elastic acrylate copolymer emulsion, LH additive, and leveling agent are added in sequence. After the addition is completed, stirring is continued at the same speed for 15min.

[0065] (4) Add thickeners RW-8W and AP-660 to adjust the viscosity to 75-85 KU, and adjust the pH value to 8-9 with pH adjuster. After stirring evenly, filter the solution to obtain water-based outdoor asphalt pavement color-changing coating.

[0066] Example 3:

[0067] A water-based outdoor asphalt pavement color-changing coating, comprising, by weight, the following raw materials: 30 parts of self-crosslinking elastic acrylic copolymer emulsion (model XL-CA), 30 parts of inorganic nano-modified acrylic emulsion (model TJG-6630), 20 parts of color-changing pigment (titanium dioxide), 0.5 parts of BYK-2012 dispersant, 0.4 parts of TEGO 4100 substrate wetting agent, 0.1 parts of BYK-024 defoamer, 0.3 parts of BYK-333 leveling agent, 0.6 parts of thickener, 5 parts of LH additive, 0.5 parts of APM-95 pH adjuster, and 10 parts of deionized water.

[0068] In this embodiment, AP-660 thickener was diluted to a concentration of 50% using deionized water. The LH additive was a mixture of ethylene glycol butyl ether, diethylene glycol butyl ether, and propylene glycol in a weight ratio of 1:3:1.

[0069] The present invention provides a method for preparing a water-based outdoor asphalt pavement color-changing coating, comprising the following steps:

[0070] Add the ingredients according to the mass proportions of the above-mentioned raw materials:

[0071] (1) Add inorganic nano-modified acrylic emulsion to the mixing tank, turn on the stirrer, and stir at a speed of 400r / min-600r / min. While stirring, add dispersant, substrate wetting agent, defoamer, color-changing pigment, and pH adjuster (60% of the formula amount) in sequence. After the addition is complete, increase the speed to 800r / min-1000r / min and disperse at this speed for 30 minutes. Clean the mixing tank with half the amount of deionized water in the formula and proceed to the next process.

[0072] (2) Use a diaphragm pump to draw the material into the sand mill, start the sand mill to circulate and grind, and control the temperature of the sand mill outlet at ≤35℃. Check the fineness after each grinding cycle until the fineness is ≤40μm. Use the other half of the deionized water to clean the sand mill and proceed to the next process.

[0073] (3) After the color paste has passed the fineness test, it is transferred to the paint mixing tank. Stirring is started. At a stirring speed of 400r / min-600r / min, self-crosslinking elastic acrylate copolymer emulsion, LH additive, and leveling agent are added in sequence. After the addition is completed, stirring is continued at the same speed for 15min.

[0074] (4) Add thickener AP-660, adjust the viscosity to 65-75KU, and adjust the pH value to 8-9 with pH adjuster. After stirring evenly, filter. The obtained filtrate is water-based outdoor asphalt pavement color-changing coating.

[0075] Comparative Example 1:

[0076] The difference between this comparative example and Example 1 is that the mass ratio of the self-crosslinking elastic acrylate copolymer emulsion (model XL-CA) to the inorganic nano-modified acrylic emulsion (model TJG-6630) is adjusted to 55:5.

[0077] Comparative Example 2:

[0078] The difference between this comparative example and Example 3 is that the mass ratio of the self-crosslinking elastic acrylate copolymer emulsion (model XL-CA) to the inorganic nano-modified acrylic emulsion (model TJG-6630) is adjusted to 10:50.

[0079] The test results of the embodiments and comparative examples of this invention are as follows:

[0080]

[0081] Example 4:

[0082] A water-based outdoor asphalt pavement color-changing coating, by weight, comprises the following raw materials: 50 parts of self-crosslinking elastic acrylic copolymer emulsion (model XL-CA), 10 parts of inorganic nano-modified acrylic emulsion (model TJG-6630), 23 parts of color-changing pigment (iron oxide red), 0.3 parts of BYK-2012 dispersant, 0.3 parts of TEGO 4100 substrate wetting agent, 0.2 parts of BYK-024 defoamer, 0.2 parts of BYK-333 leveling agent, 1.2 parts of thickener, 1 part of LH additive, 0.1 parts of APM-95 pH adjuster, and 15 parts of deionized water.

[0083] In this implementation example, AP-660 and Gel 0620 are used together as thickeners in a mass ratio of 1:2. AP-660 thickener is diluted to a 50% concentration using deionized water, and Gel 0620 thickener is diluted to a 50% concentration using ethylene glycol butyl ether. The LH additive is a mixture of ethylene glycol butyl ether, diethylene glycol butyl ether, and propylene glycol in a weight ratio of 1:3:1.

[0084] The preparation method is the same as in Example 1.

[0085] Example 5:

[0086] A water-based outdoor asphalt pavement color-changing coating, by weight, comprises the following raw materials: 50 parts of self-crosslinking elastic acrylic copolymer emulsion (model XL-CA), 10 parts of inorganic nano-modified acrylic emulsion (model TJG-6630), 24 parts of color-changing pigment (iron oxide red), 0.8 parts of BYK-2012 dispersant, 0.8 parts of TEGO 4100 substrate wetting agent, 0.3 parts of BYK-024 defoamer, 0.5 parts of BYK-333 leveling agent, 1.2 parts of thickener, 2 parts of LH additive, 0.3 parts of APM-95 pH adjuster, and 15 parts of deionized water.

[0087] In this implementation example, AP-660 and Gel 0620 are used together as thickeners in a mass ratio of 1:2. AP-660 thickener is diluted to a 50% concentration using deionized water, and Gel 0620 thickener is diluted to a 50% concentration using ethylene glycol butyl ether. The LH additive is a mixture of ethylene glycol butyl ether, diethylene glycol butyl ether, and propylene glycol in a weight ratio of 1:3:1.

[0088] The preparation method is the same as in Example 1.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-based outdoor asphalt pavement color-changing coating, characterized in that, By weight, its formulation comprises: 30-50 parts of self-crosslinking elastic acrylate copolymer emulsion, 10-30 parts of inorganic nano-modified acrylic emulsion, 20-25 parts of color-changing pigment, 0.3-0.8 parts of dispersant, 0.3-0.8 parts of substrate wetting agent, 0.1-0.3 parts of defoamer, 0.2-0.5 parts of leveling agent, 0.5-1.2 parts of thickener, 1-5 parts of LH additive, 0.1-0.5 parts of pH adjuster, and 10-15 parts of deionized water; The self-crosslinking elastic acrylate copolymer emulsion is model XL-CA; the inorganic nano-modified acrylic emulsion is model TJG-6630; the LH additive is a mixture of ethylene glycol butyl ether, diethylene glycol butyl ether, and propylene glycol in a weight ratio of 1:3:

1.

2. The water-based outdoor asphalt pavement color-changing coating according to claim 1, characterized in that, The color-changing pigment is one of iron oxide red, titanium dioxide, or organic yellow pigment.

3. The water-based outdoor asphalt pavement color-changing coating according to claim 1, characterized in that, The dispersant is one or a mixture of two of BYK-190, BYK-2012, and EFKA-4560.

4. The water-based outdoor asphalt pavement color-changing coating according to claim 3, characterized in that, The substrate wetting agent is SINPOLS PAG-30 or TEGO 4100.

5. The water-based outdoor asphalt pavement color-changing coating according to claim 4, characterized in that, The leveling agent is SN-4034 or BYK-333.

6. The water-based outdoor asphalt pavement color-changing coating according to claim 1, characterized in that, The thickener is one or a mixture of two of AP-660, RW-8W, and Gel 0620.

7. The water-based outdoor asphalt pavement color-changing coating according to claim 6, characterized in that, The thickener is AP-660.

8. The water-based outdoor asphalt pavement color-changing coating according to claim 1, characterized in that, The pH adjuster is APM-95 or SN-9730.

9. The water-based outdoor asphalt pavement color-changing coating according to claim 1, characterized in that, The defoamer is BYK-093 or BYK-024.

10. A method for preparing a water-based outdoor asphalt pavement color-changing coating as described in claim 1, characterized in that, Includes the following steps: Add ingredients according to the mass proportions of each raw material: (1) Add inorganic nano-modified acrylic emulsion into the mixing tank, and under stirring, add dispersant, substrate wetting agent, defoamer, color-changing pigment and a part of pH adjuster, stir evenly, wash the mixing tank with a part of deionized water, and then proceed to the next process. (2) The raw material from step (1) is sucked into the grinding mill and ground to a fineness of ≤40μm; the grinding mill is cleaned with the remaining deionized water and then proceeded to the next process. (3) Transfer the raw materials from step (2) into the paint mixing tank, and add the self-crosslinking elastic acrylate copolymer emulsion, LH additive, and leveling agent while stirring, and stir evenly; (4) Add thickener to adjust the viscosity to between 65-85 KU, and use the remaining pH adjuster to adjust the pH to between 8-9. Stir evenly, filter, and obtain water-based outdoor asphalt pavement color-changing coating.

Images