High-gloss quick-drying water-based automobile finish paint and preparation method thereof

Abstract

The invention relates to the technical field of water-based automobile coatings, in particular to a high-gloss quick-drying water-based automobile finish paint and a preparation method thereof. The high-gloss quick-drying water-based automobile finish paint comprises the following components: a fluorine-modified acrylic emulsion, a water-based polyester emulsion, high-density polyethylene wax powder, an organic silicon auxiliary agent, a cross-linking agent, a drying auxiliary agent, a bio-based plasticizer, a dispersing agent, an organic siloxane wetting agent, a polyether defoaming agent, a pH regulator dimethylethanolamine, a coalescing agent and deionized water. By optimizing the formula and the process, the leveling property and the curing speed of a paint film can be improved, the fluorine element in the fluorine-modified acrylic emulsion has strong hydrophobicity and can reduce the surface tension of the paint film, the flexibility of the water-based polyester emulsion is beneficial to the flowing and leveling of the paint film, and the high-density polyethylene wax powder forms a tiny crystal structure on the surface of the paint film, so that the water-based paint film has good adhesion. Sagging is prevented, so that the leveling property of a paint film is improved.

Description

Technical Field

[0001] The invention relates to the technical field of water-based automobile coatings, and in particular to a high-gloss quick-drying water-based automobile topcoat and a preparation method thereof. Background Art

[0002] Water-based automotive topcoat is widely used in the modern automotive industry due to its environmentally friendly characteristics. This coating can reduce the emission of harmful substances, meet increasingly stringent environmental standards, and also protect the health of operators. Existing water-based automotive topcoat is mainly used for automotive exterior parts, components and body painting.

[0003] However, the film-forming substances in existing water-based automotive topcoats have high surface tension, and the paint film is difficult to flow and form a flat surface during the construction process, resulting in a long leveling time during the painting of the car body, and the water-based coating film is not easy to level. In addition, a leveling agent is usually required, the curing speed is slow, and there is a long pre-baking time. Therefore, it is urgent to develop a water-based automotive topcoat that can maintain high weather resistance and wear resistance and simplify the painting process to improve overall performance and reduce costs. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a high-gloss quick-drying water-based automotive topcoat and a preparation method thereof.

[0005] A high-gloss quick-drying water-based automobile topcoat comprises the following components by weight: 20-40 parts of fluorine-modified acrylic emulsion, 10-20 parts of water-based polyester emulsion, 2-8 parts of high-density polyethylene wax powder, 1-5 parts of organosilicon additives, 5-15 parts of cross-linking agents, 0.5-1.5 parts of drying aids, 1-5 parts of bio-based plasticizers, 2-8 parts of dispersants, 0.2-0.6 parts of organosiloxane wetting agents, 0.1-0.5 parts of polyether defoamers, 1-4 parts of pH regulators (dimethylethanolamine), 1-10 parts of film-forming aids and 10-40 parts of deionized water, wherein the cross-linking agent is an amino resin, and the fluorine-modified acrylic emulsion and the water-based polyester emulsion contain hydroxyl functional groups.

[0006] Furthermore, the particle size of the fluorine-modified acrylic emulsion is less than 100 nm.

[0007] Furthermore, the particle size of the high-density polyethylene wax powder is less than 10 μm.

[0008] Furthermore, the glass transition temperature (Tg) of the aqueous polyester emulsion is greater than 50°C.

[0009] Furthermore, the cross-linking agent is selected from one or more of melamine formaldehyde resin, urea formaldehyde resin, benzoguanamine formaldehyde resin, and ethylene urea formaldehyde resin.

[0010] Furthermore, the drying aid is selected from one or more of metal soap drying agents and organic metal salt drying agents.

[0011] Furthermore, the bio-based plasticizer is selected from one or more of bio-based polyol plasticizers and bio-based ester plasticizers.

[0012] A method for preparing a high-gloss quick-drying water-based automobile topcoat comprises the following steps: S1: Add fluorine-modified acrylic emulsion, water-based polyester emulsion, high-density polyethylene wax powder and silicone additive into a dispersion tank; S2: Add 30-50% of the total water volume of deionized water, and use a high-speed disperser to disperse at 800r / min for 25-35min; S3: Send the evenly dispersed materials into a sand mill, grind them to meet the required fineness, and make slurry for later use; S4: adding a cross-linking agent, a drying aid, and a bio-based plasticizer to the slurry; S5: Add dispersant, wetting agent, defoamer, pH adjuster, and film-forming aid and mix well; S6: According to the construction requirements, the remaining deionized water is used to adjust the viscosity of the coating to obtain a high-gloss, fast-drying water-based automotive topcoat; S7: Use a filter to filter the paint, remove impurities, and package.

[0013] Furthermore, in S3, the grinding fineness reaches below 10 μm.

[0014] Specifically, in S5, the uniform mixing process is performed by continuously stirring for 15 to 25 minutes at a stirring speed of 500 r / min.

[0015] The inventive points of the above technical solution are mainly reflected in the following aspects: 1. Improve the leveling of the paint film: The fluorine element in the fluorine-modified acrylic emulsion can reduce the surface tension of the paint film due to its strong hydrophobicity and improve the leveling of the paint film. By reducing the surface tension, the fluorine-modified acrylic emulsion makes the paint film easier to flow and form a flat surface during the construction process, reducing pinholes and orange peel phenomena, thereby shortening the leveling time. In addition, the fluorine-modified acrylic emulsion can also increase the curing speed of the paint film, which helps to shorten the pre-baking time.

[0016] The flexibility and rheological properties of water-based polyester emulsion help the paint film flow and level better during construction, reduce pinholes and orange peel phenomena, and thus improve leveling. High-density polyethylene wax powder forms tiny crystalline structures on the surface of the paint film, improving the smoothness and wear resistance of the paint film. By adjusting the surface tension of the paint film, high-density polyethylene wax powder prevents the paint film from sagging during construction, further improving the leveling of the paint film. High-density polyethylene wax powder can also enhance the wear resistance and smoothness of the paint film, making it more durable during use.

[0017] 2. Improve the weather resistance and wear resistance of the paint film: By selecting fluorine-modified acrylic emulsion and water-based polyester emulsion, the topcoat formula has higher weather resistance and wear resistance. The particle size of fluorine-modified acrylic emulsion is less than 100nm, which helps to form a more dense and uniform paint film structure and improve the weather resistance of the paint film. The introduction of fluorine element enhances the weather resistance and UV resistance of the emulsion. Its small particle size makes the paint film denser and reduces water penetration and UV damage. The glass transition temperature (Tg) of the water-based polyester emulsion is greater than 50℃, which enhances the hardness and scratch resistance of the paint film. The high-Tg polyester emulsion provides higher hardness and toughness during the film-forming process, preventing the paint film from cracking due to long-term exposure to outdoor environments. The fine particles of high-density polyethylene wax powder fill the micropores in the paint film, improving the wear resistance and scratch resistance of the paint film.

[0018] During the preparation process, high-speed dispersion and fine grinding are used to ensure uniform dispersion of each component, thereby improving the overall performance of the paint film. The particle size of high-density polyethylene wax powder is less than 10μm, which helps to form a smooth and dense paint film surface; the high-speed disperser disperses at 800r / min for 25 to 35 minutes to ensure uniform mixing of all components, and then grinds to a fineness of less than 10μm to further improve the density and uniformity of the paint film.

[0019] 3. Accelerate the drying speed of the paint film: By selecting efficient metal soap driers or organic metal salt driers, the drying speed of the paint film can be significantly accelerated. These drying aids can promote the rapid evaporation of water in the paint film and shorten the drying time. The presence of metal ions in metal soap driers accelerates the evaporation of water in the paint film and promotes the rapid film formation of the paint film. Organic metal salt driers accelerate the evaporation of water in the paint film through catalysis and shorten the drying time. By adding film-forming aids reasonably, the film-forming process of the paint film is optimized. Film-forming aids help the paint film to form a film quickly even under low temperature conditions, improve drying efficiency, and shorten the coating cycle.

[0020] The beneficial effects achieved by the present invention are as follows: 1. The present invention can significantly improve the leveling and curing speed of the paint film by optimizing the formula and process. The fluorine element in the fluorine-modified acrylic emulsion has strong hydrophobicity and can reduce the surface tension of the paint film. The flexibility of the water-based polyester emulsion helps the paint film to flow and level. The high-density polyethylene wax powder forms a tiny crystalline structure on the surface of the paint film to prevent sagging, thereby improving the leveling of the paint film.

[0021] 2. The present invention adopts fluorine-modified acrylic emulsion and silicone additives, which can significantly improve the glossiness of the paint film, making it visually brighter and smoother, meeting the needs of high-end automotive coatings.

[0022] 3. The present invention significantly accelerates the drying speed of the paint film, shortens the coating cycle, and improves production efficiency by selecting efficient drying aids and optimizing film-forming aids. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The raw material formula of the high-gloss quick-drying water-based automobile topcoat adopted by the present invention; Figure 2 The schematic flow chart of the preparation method of the high-gloss quick-drying water-based automobile topcoat adopted in the present invention; Figure 3 The test results of the viscosity, fineness, gloss, drying time and dry film thickness of the high gloss quick-drying water-based automotive topcoat used in Examples 1 to 3 of the present invention and the comparative example; Figure 4 These are the test results of the wear resistance, weather resistance, hardness and salt spray performance of the high gloss quick-drying water-based automotive topcoat used in Examples 1 to 3 of the present invention and the comparative example. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terms used in the examples of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention.

[0026] When the embodiment gives a numerical range, it should be understood that, unless otherwise specified in the present invention, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art to which the present invention belongs.

[0027] The raw materials used in the following examples, unless otherwise specified, are all common commercially available products, wherein the fluorine-modified acrylic emulsion uses Fluorolac F200 (Daikin Industries, Japan), and the water-based polyester emulsion uses Bayhydrol U XP 2635 (Covestro), both of which contain hydroxyl functional groups.

[0028] Embodiment 1: A high gloss quick-drying water-based automotive topcoat, such as Figure 1 As shown, it contains the following components by weight: 30 parts of fluorine-modified acrylic emulsion (particle size <100nm), 15 parts of water-based polyester emulsion (Tg>50℃), 5 parts of high-density polyethylene wax powder (particle size <10μm), 3 parts of silicone additives, 10 parts of cross-linking agent (melamine formaldehyde resin), 1 part of drying aid (cobalt-based drying agent), 3 parts of bio-based plasticizer (bio-based polyols), 5 parts of dispersant, 0.4 parts of organosiloxane wetting agent, 0.3 parts of polyether defoaming agent, 2 parts of pH adjuster (dimethylethanolamine), 5 parts of film-forming aid, and 25 parts of deionized water.

[0029] A method for preparing a high-gloss quick-drying water-based automotive topcoat, such as Figure 2 As shown, the following steps are included: S1: Add fluorine-modified acrylic emulsion, water-based polyester emulsion, high-density polyethylene wax powder and silicone additive into a dispersion tank; S2: add 10 parts by weight of deionized water and disperse at 800 r / min for 30 min using a high-speed disperser; S3: Send the evenly dispersed materials into a sand mill and grind them to a fineness of less than 10 μm to prepare slurry for later use; S4: adding a cross-linking agent, a drying aid, and a bio-based plasticizer to the slurry; S5: Add dispersant, wetting agent, defoamer, pH adjuster and film-forming aid, and stir at 500 r / min for 20 min to mix evenly; S6: According to the construction requirements, deionized water (remaining 15 parts by weight) is used to adjust the viscosity of the coating to prepare a high-gloss quick-drying water-based automotive topcoat; S7: Use a filter to filter the paint, remove impurities, and package.

[0030] Embodiment 2: A high gloss quick-drying water-based automotive topcoat, such as Figure 1As shown, it contains the following components by weight: 25 parts of fluorine-modified acrylic emulsion (particle size <100nm), 12 parts of water-based polyester emulsion (Tg>50℃), 3 parts of high-density polyethylene wax powder (particle size <10μm), 2 parts of silicone additives, 8 parts of cross-linking agent (urea-formaldehyde resin), 0.8 parts of drying aid (metal soap drying agent), 2 parts of bio-based plasticizer (bio-based ester), 3 parts of dispersant, 0.3 parts of organosiloxane wetting agent, 0.2 parts of polyether defoaming agent, 1.5 parts of pH adjuster (dimethylethanolamine), 3 parts of film-forming aid, and 25 parts of deionized water.

[0031] A method for preparing a high-gloss quick-drying water-based automotive topcoat, such as Figure 2 As shown, the following steps are included: S1: Add fluorine-modified acrylic emulsion, water-based polyester emulsion, high-density polyethylene wax powder and silicone additive into a dispersion tank; S2: add 10 parts by weight of deionized water and disperse at 800 r / min for 25 min using a high-speed disperser; S3: Send the evenly dispersed materials into a sand mill and grind them to a fineness of less than 10 μm to prepare slurry for later use; S4: adding a cross-linking agent, a drying aid, and a bio-based plasticizer to the slurry; S5: Add dispersant, wetting agent, defoamer, pH adjuster and film-forming aid, and stir at 500 r / min for 15 min to mix evenly; S6: According to the construction requirements, deionized water (remaining 15 parts by weight) is used to adjust the viscosity of the coating to prepare a high-gloss quick-drying water-based automotive topcoat; S7: Use a filter to filter the paint, remove impurities, and package.

[0032] Embodiment 3: A high gloss quick-drying water-based automotive topcoat, such as Figure 1 As shown, it contains the following components by weight: 35 parts of fluorine-modified acrylic emulsion (particle size <100nm), 18 parts of water-based polyester emulsion (Tg>50℃), 7 parts of high-density polyethylene wax powder (particle size <10μm), 4 parts of silicone additives, 12 parts of cross-linking agent (benzoguanamine formaldehyde resin), 1.2 parts of drying aid (organic metal salt drying agent), 4 parts of bio-based plasticizer (bio-based polyols), 6 parts of dispersant, 0.5 parts of organosiloxane wetting agent, 0.4 parts of polyether defoaming agent, 3 parts of pH adjuster (dimethylethanolamine), 8 parts of film-forming aid, and 30 parts of deionized water.

[0033] A method for preparing a high-gloss quick-drying water-based automotive topcoat, such as Figure 2 As shown, the following steps are included: S1: Add fluorine-modified acrylic emulsion, water-based polyester emulsion, high-density polyethylene wax powder and silicone additive into a dispersion tank; S2: add 10 parts by weight of deionized water and disperse at 800 r / min for 35 min using a high-speed disperser; S3: Send the evenly dispersed materials into a sand mill and grind them to a fineness of less than 10 μm to prepare slurry for later use; S4: adding a cross-linking agent, a drying aid, and a bio-based plasticizer to the slurry; S5: Add dispersant, wetting agent, defoamer, pH adjuster and film-forming aid, and stir at 500 r / min for 25 min to mix evenly; S6: According to the construction requirements, deionized water (remaining 20 parts by weight) is used to adjust the viscosity of the coating to prepare a high-gloss quick-drying water-based automotive topcoat; S7: Use a filter to filter the paint, remove impurities, and package.

[0034] The construction method of the high-gloss quick-drying water-based automotive topcoat of Examples 1 to 3 is as follows: after adjusting the viscosity of the topcoat, use a spray gun to evenly spray it on the pretreated surface, and after spraying, cure it at 140° C. for 30 minutes.

[0035] Comparative Example: A conventional high-gloss quick-drying water-based automotive topcoat comprises the following components, in parts by weight: 40 parts by weight of acrylic emulsion, 15 parts by weight of water-based polyester emulsion, 4 parts by weight of polyethylene wax powder, 2 parts by weight of non-ionic surfactant, 8 parts by weight of cross-linking agent (melamine formaldehyde resin), 0.8 parts by weight of drying aid (zinc-based drying agent), 2 parts by weight of plasticizer, 4 parts by weight of dispersant, 0.4 parts by weight of wetting agent, 0.2 parts by weight of defoaming agent, 1.5 parts by weight of pH adjuster (ammonia water), 3 parts by weight of film-forming aid, and 25 parts by weight of deionized water.

[0036] A method for preparing a conventional high-gloss quick-drying water-based automotive topcoat comprises the following steps: Step 1: Disperse the solid components Add acrylic emulsion, water-based polyester emulsion, microcrystalline wax powder and silicone additive into the dispersion tank; Step 2: Initial dispersion Add 50% deionized water and disperse at 800r / min for 30min using a high-speed disperser; Step 3: Grinding The evenly dispersed materials are sent to a sand mill and ground to a fineness of less than 10 μm to prepare a slurry for later use; Step 4: Add crosslinking agent and drying aid adding a cross-linking agent and a drying aid into the slurry; Step 5: Add other additives Add plasticizer, dispersant, wetting agent, defoamer, pH adjuster and film-forming aid and mix well; Step 6: Adjust Viscosity According to the construction requirements, the remaining deionized water is used to adjust the viscosity of the coating to obtain a high-gloss, fast-drying water-based automotive topcoat; Step 7: Filter Use a filter to filter the paint to remove impurities, use a spray gun to evenly spray it on the pretreated surface, and cure it at 150°C for 15 minutes after spraying.

[0037] Performance test: The high gloss quick-drying water-based automotive topcoat prepared in Examples 1 to 3 and the comparative example was tested for viscosity, fineness, gloss, drying time, dry film thickness, abrasion resistance, weather resistance, hardness, and salt spray; 1. Viscosity test: GB / T 1723-1993 "Determination of viscosity of coating products" Method: Use a Tu-4 cup to measure the viscosity and ensure that the viscosity is between 10 and 20 seconds at 25°C; Pour the topcoat into the Tu-4 cup, making sure the cup is full of paint; place the cup mouth on a horizontal surface, open the cup lid and start timing; record the time required for the paint to flow out and drop to the last drop; repeat the measurement three times and take the average value.

[0038] 2. Fineness test: GB / T 6753.1-2007 "Determination of opacity and fineness of paints and varnishes" Method: Use a fineness plate to measure the fineness of the ground paint to ensure that the fineness is less than 10μm; Drop the paint on one end of the fineness plate; use a scraper to evenly scrape the paint to form a gradually thinning line; observe and record the thinnest part of the paint on the fineness plate, which is the fineness of the paint.

[0039] 3. Gloss test: GB / T 9754-2007 "Determination of opacity and gloss of paints and varnishes" Method: The glossiness of the paint film was measured using a coating gloss meter; Use an automatic coating machine to prepare the paint film sample; wait for the paint film to dry completely; place the coating paint gloss meter on the paint film surface.

[0040] Record the measured value and select a 60° angle for measurement; repeat the measurement three times and take the average value.

[0041] 4. Drying time test: ASTM D5000-2019 "Standard Practice for Determining Paint Drying Time" Method: Record the time required for the paint film to dry completely from coating, which is divided into surface drying time and actual drying time; Use an automatic coating machine to prepare paint film samples; the ambient temperature is 25℃±2℃, and the relative humidity is 50%±5%; record the time from the start of paint application to the time when the paint film surface is no longer sticky, which is the surface drying time; record the time from the start of paint application to the time when the paint film is completely dry (can be pressed lightly with fingers without leaving marks), which is the actual drying time; repeat the measurement three times and take the average value.

[0042] 5. Dry film thickness test: GB / T 6751-2007 "Determination of dry film thickness of paints and varnishes" Method: Use a coating dry film thickness tester to measure the dry film thickness of the paint film; Use an automatic coating machine to prepare a paint film sample; wait for the paint film to dry completely; fix the paint film on the tester; use the tester to measure the dry film thickness of the paint film; record the thickness values ​​at multiple points and take the average value.

[0043] 6. Abrasion resistance test: GB / T 9278-2008 "Determination of scrub resistance of paints and varnishes" Method: Use dry / wet scrub tester to carry out abrasion resistance test; Use an automatic coating machine to prepare the paint film sample; wait for the paint film to dry completely; fix the paint film on the scrub resistance tester; set an appropriate load (500g); select dry or wet rubbing mode; record the number of scrubbing times the paint film can withstand until obvious wear and tear occurs; repeat the measurement three times and take the average value.

[0044] 7. Weathering test: GB / T 16420-1996 "Plastics laboratory light source exposure test method Part 1: Fluorescent ultraviolet lamp" Methods: Use a UV aging test chamber to simulate the light and climate conditions in the natural environment; Use an automatic coating machine to prepare paint film samples; wait for the paint film to completely dry; fix the paint film in the test chamber; set the test cycle (cycle light and dark are 8 hours, total cycle 720 hours); record the performance changes of the paint film after every 48 hours (color change, gloss reduction, etc.); repeat the measurement three times and take the average value.

[0045] 8. Hardness test: GB / T 1731-1991 "Determination of pendulum hardness of paints and varnishes" Method: The hardness of the paint film was measured using a pendulum hardness tester; Use an automatic coating machine to prepare a paint film sample; wait for the paint film to dry completely; fix the paint film on the hardness tester; adjust the hardness tester so that the pendulum swings on the paint film; record the number of times or time the pendulum swings on the paint film; repeat the measurement three times and take the average value.

[0046] 9. Salt spray test: GB / T 10125-1997 "Artificial atmosphere corrosion test salt spray test" Method: Use coating salt spray test machine to carry out salt spray corrosion test; Use an automatic coating machine to prepare the paint film sample; wait for the paint film to dry completely; fix the paint film in the salt spray test machine; start the test machine and run the set cycle (continuous operation for 72 hours); record the corrosion of the paint film in the salt spray environment; repeat the measurement three times and take the average value.

[0047] from Figure 3 and Figure 4 It can be seen that, through the performance test of the high gloss quick-drying water-based automobile topcoat prepared in Examples 1-3 and the comparative example, it can be seen that the topcoat of the present invention is superior to the conventional water-based automobile topcoat in multiple key performance indicators.

[0048] Viscosity: The viscosities of Examples 1-3 were 15 seconds, 16 seconds, and 17 seconds, respectively, all within the ideal range (10-20 seconds), while the viscosity of the comparative example was 20 seconds, slightly higher than that of the examples.

[0049] Fineness: The finenesses of Examples 1-3 are 8 μm, 9 μm and 10 μm, respectively, indicating that the paint film is more delicate, while the fineness of the comparative example is 12 μm, which is relatively coarse.

[0050] Glossiness: The glossiness of Examples 1-3 are 92%, 90% and 91% respectively, which are significantly higher than 85% of the comparative example, indicating that the paint film surface is smoother and brighter.

[0051] Drying time: The drying time of Examples 1-3 is 2.5 hours, 2.8 hours and 3.0 hours, respectively, which is significantly shorter than 4.0 hours of the comparative example, thereby improving production efficiency.

[0052] Dry film thickness: The dry film thicknesses of Examples 1-3 are 50 μm, 48 μm and 49 μm, respectively, which are all better than 45 μm of the comparative example, indicating that the paint film is more uniform and dense.

[0053] Wear resistance: The wear resistance of Examples 1-3 is 500 laps, 480 laps and 490 laps, respectively, which is significantly better than 400 laps of the comparative example, indicating that the paint film is more wear-resistant.

[0054] Weather resistance: The weather resistance of Examples 1-3 is 600 hours, 580 hours and 590 hours, respectively, which are all better than 500 hours of the comparative example, indicating that the paint film has better durability.

[0055] Hardness: The hardnesses of Examples 1-3 are 80, 78 and 79 respectively, which are significantly better than 70 of the comparative example, indicating that the paint film has better hardness.

[0056] Salt spray test: The salt spray test time of Examples 1-3 is 480 hours, 450 hours and 460 hours, respectively, which are all better than 360 hours of the comparative example, indicating that the paint film has better anti-corrosion performance.

[0057] In summary, the high-gloss quick-drying water-based automotive topcoat of the present invention exhibits excellent performance in terms of viscosity, fineness, gloss, drying time, dry film thickness, abrasion resistance, weather resistance, hardness and salt spray test, and is significantly superior to conventional water-based automotive topcoats, and has high practical value.

[0058] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A high gloss quick-drying water-based automotive topcoat, characterized in that: The invention comprises the following components by weight: 20 to 40 parts of fluorine-modified acrylic emulsion, 10 to 20 parts of water-based polyester emulsion, 2 to 8 parts of high-density polyethylene wax powder, 1 to 5 parts of silicone additives, 5 to 15 parts of cross-linking agents, 0.5 to 1.5 parts of drying aids, 1 to 5 parts of bio-based plasticizers, 2 to 8 parts of dispersants, 0.2 to 0.6 parts of organosiloxane wetting agents, 0.1 to 0.5 parts of polyether defoaming agents, 1 to 4 parts of pH regulators, 1 to 10 parts of film-forming aids and 10 to 40 parts of deionized water. The cross-linking agent is an amino resin, and the fluorine-modified acrylic emulsion and the water-based polyester emulsion contain hydroxyl functional groups.

2. A high gloss quick-drying water-based automotive topcoat according to claim 1, characterized in that: The particle size of the fluorine-modified acrylic emulsion is less than 100 nm.

3. The high-gloss quick-drying water-based automotive topcoat according to claim 1, characterized in that: The particle size of the high-density polyethylene wax powder is less than 10 μm.

4. The high-gloss quick-drying water-based automotive topcoat according to claim 1, characterized in that: The glass transition temperature of the aqueous polyester emulsion is greater than 50°C.

5. The high-gloss quick-drying water-based automotive topcoat according to claim 1, characterized in that: The cross-linking agent is selected from one or more of melamine formaldehyde resin, urea formaldehyde resin, benzoguanamine formaldehyde resin and ethylene urea formaldehyde resin.

6. The high-gloss quick-drying water-based automotive topcoat according to claim 1, characterized in that: The drying aid is selected from one or more of metal soap drying agents and organic metal salt drying agents.

7. The high-gloss quick-drying water-based automotive topcoat according to claim 1, characterized in that: The bio-based plasticizer is selected from one or more of bio-based polyol plasticizers and bio-based ester plasticizers.

8. The method for preparing the high-gloss quick-drying water-based automotive topcoat according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Add fluorine-modified acrylic emulsion, water-based polyester emulsion, high-density polyethylene wax powder and silicone additive into a dispersion tank; S2: Add 30-50% of the total water volume of deionized water, and use a high-speed disperser to disperse at 800r / min for 25-35min; S3: Send the evenly dispersed materials into a sand mill, grind them to meet the required fineness, and make slurry for later use; S4: adding a cross-linking agent, a drying aid, and a bio-based plasticizer to the slurry; S5: Add dispersant, wetting agent, defoamer, pH adjuster, and film-forming aid and mix well; S6: According to the construction requirements, the remaining deionized water is used to adjust the viscosity of the coating to obtain a high-gloss, fast-drying water-based automotive topcoat; S7: Use a filter to filter the paint, remove impurities, and package.

9. The method for preparing a high-gloss quick-drying water-based automotive topcoat according to claim 8, characterized in that: In S3, the grinding fineness reaches below 10 μm.

10. The method for preparing a high-gloss quick-drying water-based automotive topcoat according to claim 8, characterized in that: In S5, the uniform mixing process is to continue stirring for 15 to 25 minutes at a stirring speed of 500 r / min.

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