High-brightness water-based facade reflective marking paint and preparation method thereof

Abstract

This invention discloses a high-brightness water-based reflective road marking paint and its preparation method, belonging to the technical field of road marking paints. The paint is made from the following raw materials in parts by weight: 20-35 parts water-based acrylic emulsion, 20-30 parts water, 25-30 parts glass microspheres, 10-15 parts flake pearlescent powder, 1-2 parts wetting and dispersing agent, 0.2-0.5 parts anti-settling agent, 5-10 parts modified pearlescent powder, and 1-3 parts pearlescent powder orientation agent. The modified pearlescent powder is obtained by grafting flake pearlescent powder with silane coupling agent KH550 and polyvinyl alcohol, significantly improving its dispersibility in the water-based system. The pearlescent powder orientation agent is a comb-like polymer copolymerized from acrylic acid, macromonomer EPEG3000, and 3-pentenoic acid monoglyceride in a specific mass ratio, which effectively promotes the oriented and orderly arrangement of pearlescent powder during film formation, forming a highly efficient reflective layer. The synergistic effect of these two factors gives the coating of this invention an extremely high retroreflective brightness coefficient (≥578 mcd / m). 2 / lx), which is far superior to traditional products, and also has the advantages of readily available raw materials and simple processes.

Description

Technical Field

[0001] This invention belongs to the field of road marking paint technology, specifically relating to a high-brightness water-based reflective vertical marking paint and its preparation method. Background Technology

[0002] Reflective warning markings utilize the principle of retroreflection to achieve high visibility at night or in low-light environments. The main materials used in their installation are reflective film and reflective paint. Traditional high-intensity reflective film has a frontal brightness of approximately 250 mcd / m². 2 / lx, but its performance degrades significantly at large observation angles (e.g., 2°) or in rainy night conditions. While full-prism reflective films have high reflectivity (e.g., diamond-grade can reach 800 mcd / m), 2 While reflective film can be applied to smooth surfaces (e.g., / lx), it is expensive and limited by installation angle. Furthermore, it requires application to rough surfaces like concrete, necessitating additional steps (such as anchoring tinplate or using specialized adhesive). Initial installation is complex and subject to structural limitations, making it difficult to apply to irregularly shaped surfaces and prone to air bubbles or wrinkles. Post-installation maintenance is also problematic, as adhesive aging, temperature changes, or mechanical abrasion can cause peeling and detachment, requiring complete removal and reapplication, which is time-consuming and labor-intensive. Reflective coatings can achieve a retroreflection coefficient of 300-400 mcd / m². 2 / lx (measured value), maintaining high brightness even in rainy nights or humid environments (e.g., retroreflection coefficient ≥100 mcd / m during continuous rainfall). 2 ( / lx), and research has found that reflective paint has excellent wide-angle visibility. Generally, reflective paint is applied by spraying or brushing and can be directly adhered to various surfaces such as cement concrete, wood, metal, and asphalt, including uneven or irregularly shaped structures (such as bridge piers, tunnel walls, and crash barriers). Its application requires no additional substrate treatment (such as for galvanized sheet installation), supports automated spraying, is highly efficient, and can achieve multi-color, one-time application.

[0003] Chinese patent CN106349838A discloses an ultra-wide-angle, high-brightness water-based environmentally friendly facade reflective coating and its preparation method. The reflective coating requires the following materials by weight: 20-30 parts water-based acrylic resin, 1-5 parts film-forming aid, 0.1-10 parts co-solvent, 10-20 parts metallic pigment, 5-15 parts distilled water, 6-15 parts coloring pigment, 20-60 parts reflective carrier, and 1-3 parts additives. The additives are a mixture of wetting and dispersing agents, leveling agents, preservatives, thickeners, and defoamers in any proportion. This patent produces a relatively low retroreflection coefficient of only 288 mcd / m². 2The value of / lx fails to meet national standards. Chinese patent CN119662089A discloses a formula, preparation method, and preparation apparatus for a facade reflective coating. The materials required for the reflective coating, by weight, include: 30-40 parts epoxy resin, 15-20 parts glass microspheres, 10-20 parts ceramic microspheres, 6-8 parts titanium dioxide, 1-2 parts polycarboxylate dispersant, 0.5-1 part silicone defoamer, 1-2 parts hydroxyethyl cellulose thickener, 1 part silane coupling agent, and 20-30 parts deionized water. This patent does not provide a specific value for the retroreflection coefficient. Because this patent only improves the bonding strength between the reflective material and the matrix resin through modification, without considering the retroreflection situation after film formation, the problem of low retroreflection coefficient and lack of brightness in traditional reflective coatings remains unsolved. It can be found that there is still room for improvement in the reflective performance of reflective coatings. This paper obtains reflective coatings with high retroreflection coefficients by combining and modifying different reflective materials. The production operation is simple and convenient and the cost is low. It has been mass-produced and launched to the market. Summary of the Invention

[0004] The purpose of this invention is to provide a high-brightness water-based reflective facade coating to further improve the brightness and retroreflection of water-based reflective facade coatings.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0006] A high-gloss water-based reflective facade coating is made from the following raw materials in parts by weight: 20-35 parts water-based acrylic emulsion, 20-30 parts water, 25-30 parts glass microspheres, 10-15 parts flake pearlescent powder, 1-2 parts wetting and dispersing agent, 0.2-0.5 parts anti-settling agent, 5-10 parts modified pearlescent powder, and 1-3 parts pearlescent powder orientation agent;

[0007] The modified pearlescent powder is prepared by reacting flake pearlescent powder, silane coupling agent KH550 and polyvinyl alcohol at a mass ratio of 100:(1~1.5):5; the polyvinyl alcohol is PVA0388.

[0008] The pearlescent powder orientation agent is prepared by copolymerization of acrylic acid, macromonomer EPEG3000 and 3-pentenoic acid monoglyceride in a mass ratio of 10:90:2.

[0009] Preferably, the modified pearlescent powder is prepared by the following method: silane coupling agent KH550, water, and ethanol are mixed and hydrolyzed at a mass ratio of 2:1:9 for 30 min, then flake pearlescent powder and polyvinyl alcohol are added, and the mixture is stirred at high speed at 75~90℃ for 30~45 min to obtain the modified pearlescent powder.

[0010] Preferably, the pearlescent powder alignment agent is prepared by the following method:

[0011] (a) Initiator A and water are added to acrylic acid and mixed to obtain component A;

[0012] (b) Initiator B, chain transfer agent and water are mixed evenly to obtain component B;

[0013] (c) Mix macromonomer EPEG3000, 3-pentenoic acid monoglyceride and water evenly to obtain a substrate. At the same time, add component A and component B dropwise to the substrate while stirring. The dropwise addition time is controlled at 90~120min. After the dropwise addition is completed, add saturated liquid alkali to neutralize and obtain pearlescent powder orientation agent.

[0014] Preferably, the initiator A is VC, and the amount used is 1% to 2% of the mass of acrylic acid, and the mass ratio of water to acrylic acid in component A is 0.8:1.

[0015] Preferably, the initiator B is ammonium persulfate, and the amount used is 3% to 5% of the mass of acrylic acid; the chain transfer agent is mercaptopropionic acid; and the mass ratio of water to acrylic acid in component B is 0.2:1.

[0016] Preferably, in step (c), the amount of water in the substrate is 80 times the mass of 3-pentenoic acid monoglyceride; the amount of saturated alkali is the same as the mass of acrylic acid.

[0017] Preferably, the glass microspheres have a retroreflection coefficient of 1.9 and a particle size of 200-350 mesh.

[0018] Preferably, the wetting and dispersing agent is one of LD70A or LD64200.

[0019] Preferably, the aqueous acrylic emulsion is at least one of LA1909, PRIMAL NW-5118, and PRIMAL B-959; and the flake pearlescent powder is at least one of Paliocrom Gold L200, Iriodin 504, and PM-200.

[0020] Preferably, the anti-settling agent is one of montmorillonite, hydroxymethyl cellulose powder, or a saturated solution of hydroxymethylpropyl cellulose.

[0021] This invention also provides a method for preparing a high-brightness water-based reflective facade paint, which includes the following steps:

[0022] (1) Prepare modified pearlescent powder and pearlescent powder orientation agent respectively;

[0023] (2) Add water-based acrylic emulsion, water, and wetting and dispersing agent to a dispersion vessel and stir at 1500r / min~2000r / min for 15~20min. Then add flake pearl powder, modified pearl powder, anti-settling agent, pearl powder orientation agent and glass microspheres and stir again at 2500r / min~3000r / min for 20~30min. Filter with a 60-mesh filter and pack into a barrel to obtain the final product.

[0024] The beneficial effects of this invention are as follows:

[0025] (1) This invention improves the retroreflective properties of water-based reflective facade coatings by adding modified pearlescent powder and a pearlescent powder orientation agent. The modified pearlescent powder is prepared from flake pearlescent powder, KH550, and PVA0388. KH550 can undergo a coupling reaction with flake pearlescent powder and PVA0388. PVA0388 is grafted onto the flake pearlescent powder through the coupling reaction with KH550, which improves the hydrophilicity of the pearlescent powder, makes the pearlescent powder more dispersible in water, and allows the pearlescent powder to be arranged more uniformly. The pearlescent powder orientation agent is made from propylene. It is prepared by reacting acid, EPEG3000, and 3-pentenoic acid monoglyceride. The three substances, acrylic acid, EPEG3000, and 3-pentenoic acid monoglyceride, are copolymerized to form a comb-like molecular chain. The carboxyl groups on the molecular chain can form a chelating effect with the metal layer on the surface of the pearlescent powder, and the hydroxyl groups on the molecular chain can increase the adsorption force on water. The polyoxyethylene side chain can form a super-dispersion in water and swing with the flow of water, thereby indirectly driving the arrangement of the pearlescent powder. This allows the pearlescent powder to form a thinner, more uniform, and flatter physical reflective structure in water, thus significantly improving the retroreflective effect.

[0026] (2) The raw materials for the high-brightness water-based reflective facade coating of the present invention are readily available, inexpensive, and easy to process. At the same time, the preparation method of the present invention can obtain the high-brightness water-based reflective facade coating by simply stirring once and then discharging and packing it into a barrel. The production operation is simple, no additional processing equipment is required, the cost is low, and it is suitable for large-scale production.

[0027] (3) Experiments have shown that the high-brightness water-based reflective facade coating prepared using the modified pearlescent powder and pearlescent powder orientation agent of this invention has a retroreflective brightness coefficient ≥578mcd / m 2 / lx has a significant advantage in retroreflective coefficient compared to ordinary water-based reflective facade coatings made without the addition of modified pearlescent powder and pearlescent powder orientation agent. Attached Figure Description

[0028] Figure 1 The results of the retroreflection brightness test on the facade of the product obtained in Embodiment 1 of the present invention;

[0029] Figure 2The results of the horizontal plane test of the retroreflection brightness of the product obtained in Embodiment 1 of the present invention are shown. Detailed Implementation

[0030] The technical solution of the present invention will be further described below with reference to specific embodiments, but it is not limited thereto.

[0031] Example 1

[0032] A high-brightness water-based reflective facade coating is made from the following raw materials in parts by weight: 200 kg of water-based acrylic emulsion (brand name PRIMAL B-959), 300 kg of water, 300 kg of glass microspheres, 100 kg of flake pearlescent powder Paliocolon Gold L200, 10 kg of wetting and dispersing agent LD70A, 5 kg of 1250 mesh montmorillonite, 100 kg of modified pearlescent powder, and 10 kg of pearlescent powder orientation agent. The glass microspheres are 200 mesh glass microspheres with a retroreflective coefficient of 1.9.

[0033] The modified pearlescent powder is prepared as follows: 2 kg KH550, 9 kg ethanol, and 1 kg water are mixed and stirred for 30 minutes until a transparent solution is obtained to obtain hydrolyzed KH550. First, 100 kg of flake pearlescent powder Paliocolon Gold L200 is added to a high-speed mixer, and then the high-speed mixer is heated to 75°C. After the temperature is reached, 1.5 kg of hydrolyzed KH550 and 5 kg of PVA0388 are added while stirring. After the addition is completed, the speed of the high-speed mixer is increased to 2000 r / min, and the reaction is carried out for 45 minutes. After the reaction is completed, the modified pearlescent powder can be obtained.

[0034] The pearlescent powder orientation agent is prepared as follows: 1 kg of acrylic acid, 0.8 kg of water, and 10 g of vitamin C are mixed evenly to obtain component A. 30 g of ammonium persulfate, 5 g of mercaptopropionic acid, and 0.2 kg of water are mixed evenly to obtain component B. 9 kg of EPGE3000, 0.2 kg of 3-pentenoic acid monoglyceride, and 16 kg of water are added to a reaction vessel. Components A and B are first connected to peristaltic pumps, which are then connected to the reaction vessel. Without heating, the reaction vessel is directly stirred at a speed of 500 r / min. Components A and B are added dropwise while stirring for 90 minutes. After the addition is complete, 1 kg of saturated liquid alkali is added. After the addition is complete, the pearlescent powder orientation agent is obtained.

[0035] A method for preparing a high-brightness water-based reflective facade paint includes the following steps:

[0036] (1) Prepare modified pearlescent powder and pearlescent powder orientation agent respectively;

[0037] (2) Add PRIMAL B-959, water, and wetting and dispersing agent to the dispersion kettle and stir for 15 minutes at 1500 r / min. Then add flake pearl powder, modified pearl powder, anti-settling agent, pearl powder orientation agent, and glass microspheres and stir again for 30 minutes at 2500 r / min. After stirring, release the coating and filter it through a 60-mesh filter to obtain a high-brightness water-based vertical reflective line light coating.

[0038] Example 2

[0039] A high-brightness water-based reflective facade coating is made from the following raw materials in parts by weight: 300 kg of water-based acrylic emulsion (brand name LA1909), 200 kg of water, 250 kg of glass microspheres, 150 kg of flake pearlescent powder Iriodin 504, 1.5 kg of wetting and dispersing agent LD64200, 2 kg of anti-settling agent hydroxymethyl cellulose powder, 50 kg of modified pearlescent powder, and 30 kg of pearlescent powder orientation agent. The glass microspheres are 350-mesh glass microspheres with a retroreflective coefficient of 1.9.

[0040] The modified pearlescent powder is prepared as follows: 1 kg KH550, 4.5 kg ethanol, and 0.5 kg water are mixed and stirred for 30 minutes until a transparent solution is obtained to obtain hydrolyzed KH550. First, 50 kg of flake pearlescent powder Iriodin 504 is added to a high-speed mixer, and then the high-speed mixer is heated to 90°C. After the temperature is reached, 0.75 kg of hydrolyzed KH550 and 2.5 kg of PVA0388 are added while stirring. After the addition is completed, the speed of the high-speed mixer is increased to 2500 r / min, and the reaction is carried out for 30 minutes. After the reaction is completed, the modified pearlescent powder can be obtained.

[0041] The pearlescent powder orientation agent is prepared as follows: 3 kg of acrylic acid, 2.4 kg of water, and 30 g of vitamin C are mixed evenly to obtain component A. 90 g of ammonium persulfate, 15 g of mercaptopropionic acid, and 0.6 kg of water are mixed evenly to obtain component B. 27 kg of EPGE3000, 0.6 kg of 3-pentenoic acid monoglyceride, and 48 kg of water are added to a reaction vessel. Components A and B are first connected to peristaltic pumps, which are then connected to the reaction vessel. Without heating, the reaction vessel is directly stirred at a speed of 500 r / min. Components A and B are added dropwise while stirring for 100 min. After the addition is complete, 3 kg of saturated liquid alkali is added. After the addition is complete, the pearlescent powder orientation agent is obtained.

[0042] A method for preparing a high-brightness water-based reflective facade paint, comprising the following steps:

[0043] (1) Prepare modified pearlescent powder and pearlescent powder orientation agent respectively;

[0044] (2) Add LA1909, water, and wetting and dispersing agent to the dispersion kettle and stir once at 2000 r / min for 20 min. Then add flake pearl powder, modified pearl powder, anti-settling agent, pearl powder orientation agent, and glass microspheres and stir again at 3000 r / min for 20 min. After stirring, release the coating and filter it through a 60-mesh filter to obtain high-brightness water-based vertical reflective line light coating.

[0045] Example 3

[0046] A high-brightness water-based reflective facade coating is made from the following raw materials in parts by weight: 35 parts water-based acrylic emulsion (brand name PRIMAL NW-5118), 25 parts water, 30 parts glass microspheres, 12 parts flake pearlescent powder PM-200, 2 parts wetting and dispersing agent LD64200, 0.4 parts anti-settling agent saturated solution of hydroxymethyl cellulose, 10 parts modified pearlescent powder, and 2 parts pearlescent powder orientation agent. The glass microspheres consist of 10 kg of 250-mesh glass microspheres with a retroreflective coefficient of 1.9 and 20 kg of 300-mesh glass microspheres.

[0047] The modified pearlescent powder is prepared as follows: 2 kg KH550, 9 kg ethanol and 1 kg water are mixed and stirred for 30 minutes until a transparent solution is obtained to obtain hydrolyzed KH550. First, 100 kg of flake pearlescent powder PM-200 is added to a high-speed mixer, and then the high-speed mixer is heated to 75°C. After the temperature is reached, 1.5 kg of hydrolyzed KH550 and 5 kg of PVA0388 are added while stirring. After the addition is completed, the speed of the high-speed mixer is increased to 2700 r / min and the reaction is carried out for 40 minutes. After the reaction is completed, the modified pearlescent powder can be obtained.

[0048] The preparation method of the pearlescent powder orientation agent is as follows: 1 kg of acrylic acid, 0.8 kg of water, and 10 g of vitamin C are mixed evenly to obtain component A. 30 g of ammonium persulfate, 5 g of mercaptopropionic acid, and 0.2 kg of water are mixed evenly to obtain component B. 9 kg of EPGE3000, 0.2 kg of 3-pentenoic acid monoglyceride, and 16 kg of water are added to a reaction vessel. Components A and B are first connected to peristaltic pumps, which are then connected to the reaction vessel. Without heating, the reaction vessel is directly stirred at a speed of 500 r / min. Components A and B are added dropwise while stirring for 120 min. After the addition is complete, 1 kg of saturated liquid alkali is added. After the addition is complete, the pearlescent powder orientation agent is obtained.

[0049] A method for preparing a high-brightness water-based reflective facade paint, comprising the following steps:

[0050] (1) Prepare modified pearlescent powder and pearlescent powder orientation agent respectively;

[0051] (2) Add PRIMAL NW-5118, water, and wetting and dispersing agent to the dispersion kettle and stir once at 1800 r / min for 20 min. Then add flake pearl powder, modified pearl powder, anti-settling agent, pearl powder orientation agent, and glass microspheres and stir again at 2800 r / min for 25 min. After stirring, release the coating and filter it through a 60-mesh filter to obtain a high-brightness water-based vertical reflective line light coating.

[0052] Example 4

[0053] A high-gloss water-based reflective facade coating is made from the following raw materials in parts by weight: 350 kg water-based acrylic emulsion, 350 kg water, 280 kg glass microspheres; 150 kg flake pearlescent powder, 20 kg wetting and dispersing agent LD70A, 5 kg anti-settling agent saturated hydroxymethyl cellulose solution, 80 kg modified pearlescent powder, and 20 kg pearlescent powder orientation agent. The water-based acrylic emulsion contains 150 kg of PRIMAL NW-5118 and 200 kg of LA1909; the flake pearlescent powder contains 100 kg of PM-200 and 50 kg of PRIMAL NW-5118. The glass microspheres are 250-mesh glass microspheres with a retroreflective coefficient of 1.9.

[0054] The modified pearlescent powder is prepared as follows: 1.6 kg KH550, 7.2 kg ethanol, and 0.8 kg water are mixed and stirred for 30 minutes until a transparent solution is obtained to obtain hydrolyzed KH550. First, 80 kg of flake pearlescent powder Iriodin 504 is added to a high-speed mixer, and then the high-speed mixer is heated to 80°C. After the temperature is reached, 1.2 kg of hydrolyzed KH550 and 4 kg of PVA0388 are added while stirring. After the addition is completed, the speed of the high-speed mixer is increased to 3000 r / min, and the reaction is carried out for 35 minutes. After the reaction is completed, the modified pearlescent powder can be obtained.

[0055] The preparation method of the pearlescent powder orientation agent is as follows: 1 kg of acrylic acid, 0.8 kg of water, and 10 g of vitamin C are mixed evenly to obtain component A. 30 g of ammonium persulfate, 5 g of mercaptopropionic acid, and 0.2 kg of water are mixed evenly to obtain component B. 9 kg of EPGE3000, 0.2 kg of 3-pentenoic acid monoglyceride, and 16 kg of water are added to a reaction vessel. Components A and B are first connected to peristaltic pumps, which are then connected to the reaction vessel. Without heating, the reaction vessel is directly stirred at a speed of 500 r / min. Components A and B are added dropwise while stirring for 90 min. After the addition is complete, 1 kg of saturated liquid alkali is added. After the addition is complete, the pearlescent powder orientation agent is obtained.

[0056] A method for preparing a high-brightness water-based reflective facade paint, comprising the following steps:

[0057] (1) Prepare modified pearlescent powder and pearlescent powder orientation agent respectively;

[0058] (2) Add water-based acrylic emulsion, water, and wetting and dispersing agent to a dispersion tank and stir once at 1500 r / min for 20 min. Then add flake pearl powder, modified pearl powder, anti-settling agent, pearl powder orientation agent, and glass microspheres and stir again at 3000 r / min for 20 min. After stirring, release the coating and filter it through a 60-mesh filter to obtain a high-brightness water-based vertical reflective line light coating.

[0059] Comparative Example 1

[0060] A high-brightness water-based reflective facade coating has the same raw material composition and preparation method as in Example 1, except that the modified pearlescent powder is replaced with flake pearlescent powder Paliocolon Gold L200.

[0061] Comparative Example 2

[0062] A high-brightness water-based reflective facade coating has the same raw material composition and preparation method as in Example 1. The only difference is that the preparation method of the pearlescent powder orientation agent only uses acrylic acid and EPEG3000 to react and does not contain 3-pentenoic acid monoglyceride. The remaining components and preparation steps are the same as in Example 1.

[0063] Comparative Example 3

[0064] A high-brightness water-based reflective facade coating has the same raw material composition and preparation method as in Example 1. The only difference is that the preparation method of the pearlescent powder orientation agent only uses acrylic acid and 3-pentenoic acid monoglyceride reaction, and does not use EPEG3000 reaction. The remaining components and preparation steps are the same as in Example 1.

[0065] Comparative Example 4

[0066] A high-brightness water-based reflective facade coating has the same raw material composition and preparation method as in Example 1. The only difference is that the preparation method of the pearlescent powder orientation agent only uses EPEG3000 and 3-pentenoic acid monoglyceride reaction, and does not use acrylic acid reaction. The remaining components and preparation steps are the same as in Example 1.

[0067] Comparative Example 5

[0068] A high-brightness water-based reflective facade coating has the same raw material composition and preparation method as in Example 1, except that no pearlescent powder directional alignment agent is added.

[0069] Comparative Example 6

[0070] A high-brightness water-based reflective facade coating has the same raw material composition and preparation method as in Example 1, except that the modified pearlescent powder is replaced with an equal amount of the original flake pearlescent powder Paliocolon Gold L200, and no pearlescent powder orientation agent is added.

[0071] Performance testing

[0072] According to the test standard described in JT / T 1327-2020, the retroreflection luminance coefficients of Examples 1-4 and Comparative Examples 1-6 were tested. Specific results are shown in Table 1 and... Figure 1-2 .

[0073] Table 1 Test Results

[0074]

[0075] As shown in Table 1, the retroreflection coefficient of the coatings prepared using Examples 1-4 of this invention is consistently 578 mcd / m. 2 Above / lx, up to 676 mcd / m 2 / lx, and the horizontal plane coefficient exceeds 700 mcd / m 2 / lx, significantly superior to existing products (~300-400 mcd / m 2 / lx), which fully demonstrates the excellent effect of the present invention. Figure 1 and Figure 2 The figures show the results of the vertical and horizontal tests in Example 1 of this invention. The test results of Comparative Examples 1-6 are significantly lower than those of the embodiments of this invention. Specifically, compared to Examples 1-4, Comparative Example 1 shows a significant performance decrease, demonstrating that the modified pearlescent powder significantly contributes to high performance by improving dispersibility. The performance of Comparative Examples 2-4 also shows severe degradation, all lower than Comparative Example 5. This indicates that the ternary copolymer structure of the pearlescent powder oriented agent described in this invention is a necessary condition for producing excellent results; the absence of any monomer will severely impair its function, highlighting the non-obviousness and synergistic effect of this molecular design. Comparative Example 5 also exhibits poor performance without the pearlescent powder oriented agent. Comparative Example 6 has the worst performance among all groups, indicating that, based on the most basic original formulation, this invention brings a significant synergistic gain effect by combining the modified pearlescent powder and the pearlescent powder oriented agent. By comparing with Comparative Examples 1, 5-6 and Example 1, it is fully demonstrated that the combined use of modified pearlescent powder and pearlescent powder orientation agent produces a technical effect of "1+1>2", ultimately achieving a leap in retroreflective performance.

[0076] It should be noted that the above embodiments are merely some preferred embodiments of the present invention, and not all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

Claims

1. A high-brightness water-based reflective facade coating, characterized in that, It is made from the following raw materials in parts by weight: 20-35 parts of water-based acrylic emulsion, 20-30 parts of water, 25-30 parts of glass microspheres, 10-15 parts of flake pearlescent powder, 1-2 parts of wetting and dispersing agent, 0.2-0.5 parts of anti-settling agent, 5-10 parts of modified pearlescent powder, and 1-3 parts of pearlescent powder orientation agent; The modified pearlescent powder is prepared by reacting flake pearlescent powder, silane coupling agent KH550 and polyvinyl alcohol in a mass ratio of 100:(1~1.5):5; The pearlescent powder orientation agent is prepared by copolymerization of acrylic acid, macromonomer EPEG3000 and 3-pentenoic acid monoglyceride in a mass ratio of 10:90:2; The modified pearlescent powder is prepared by the following method: silane coupling agent KH550, water and ethanol are mixed and hydrolyzed in a mass ratio of 2:1:9 for 30 min, then flake pearlescent powder and polyvinyl alcohol are added, and the mixture is stirred at high speed at 75~90℃ for 30~45 min to obtain the modified pearlescent powder. The pearlescent powder alignment agent is prepared by the following method: (a) Initiator A and water are added to acrylic acid and mixed to obtain component A; (b) Initiator B, chain transfer agent and water are mixed evenly to obtain component B; (c) Mix macromonomer EPEG3000, 3-pentenoic acid monoglyceride and water evenly to obtain a substrate. At the same time, add component A and component B dropwise to the substrate while stirring. The dropwise addition time is controlled at 90~120min. After the dropwise addition is completed, add saturated liquid alkali to neutralize and obtain pearlescent powder orientation agent.

2. The high-brightness water-based reflective facade coating according to claim 1, characterized in that, The initiator A is VC, and the amount used is 1% to 2% of the mass of acrylic acid. The mass ratio of water to acrylic acid in component A is 0.8:

1.

3. The high-brightness water-based reflective facade coating according to claim 1, characterized in that, The initiator B is ammonium persulfate, and its dosage is 3% to 5% of the mass of acrylic acid; the chain transfer agent is mercaptopropionic acid; the mass ratio of water to acrylic acid in component B is 0.2:

1.

4. The high-brightness water-based reflective facade coating according to claim 1, characterized in that, In step (c), the amount of water in the substrate is 80 times the mass of 3-pentenoic acid monoglyceride; the amount of saturated alkali is the same as the mass of acrylic acid.

5. The high-brightness water-based reflective facade coating according to claim 1, characterized in that, The glass microspheres have a retroreflection coefficient of 1.9 and a particle size of 200-350 mesh.

6. The high-brightness water-based reflective facade coating according to claim 1, characterized in that, The anti-settling agent is one of montmorillonite, hydroxymethyl cellulose powder, or saturated hydroxymethyl propyl cellulose solution.

7. A method for preparing a high-brightness water-based reflective facade paint according to any one of claims 1-6, characterized in that, It includes the following steps: (1) Prepare modified pearlescent powder and pearlescent powder orientation agent respectively; (2) Add water-based acrylic emulsion, water, and wetting and dispersing agent to a dispersion vessel and stir at 1500r / min~2000r / min for 15~20min. Then add flake pearl powder, modified pearl powder, anti-settling agent, pearl powder orientation agent and glass microspheres and stir again at 2500r / min~3000r / min for 20~30min. Filter with a 60-mesh filter and pack into a barrel to obtain the final product.

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