Special pigment printing paste for automobile highlight black and preparation method thereof

Abstract

The invention relates to the technical field of pigment color paste, and discloses pigment color paste special for automobile highlight black and a preparation method of the pigment color paste, and the pigment color paste is prepared by taking environment-friendly polyurethane resin, melanin pigment, a nano silicon dioxide filler, a flatting agent, a defoaming agent, zirconium oxide nanoparticles and anti-ultraviolet microcapsules as raw materials. On one hand, the construction performance of the pigment color paste is improved through regulation and control of a formula, on the other hand, the content of volatile organic compounds is reduced through selection of environment-friendly polyurethane resin, and on the third hand, by preparation of the anti-ultraviolet microcapsules and utilization of hindered amine functional groups and nano titanium dioxide in the anti-ultraviolet microcapsules, the anti-ultraviolet performance of the pigment color paste is improved. According to the present invention, the pigment color paste is endowed with the excellent UV protection function, the aging resistance of the pigment color paste is improved, the pigment color paste can maintain the good and stable performance under the long-term outdoor condition, and the application range of the pigment color paste in the severe environment is broadened.

Description

Technical Field

[0001] The present invention relates to the technical field of coating color pastes, in particular to a coating color paste dedicated to automotive high-gloss black and a preparation method thereof. Background Art

[0002] With the continuous development of the automotive market, consumers are increasingly demanding higher quality in their vehicles' exteriors, and the demand for black automotive coatings is increasing year by year. The R&D technology for black coatings is relatively mature. Black paste can serve as an intermediate product in the coating production process, allowing for the production of varying black coating qualities through blending. The resulting appearance of black coatings enhances the vehicle's class and aesthetics. By blending and adding different ingredients, black paste can optimize the coating production process and reduce costs. The development and application of black paste as an intermediate product can improve the coating's applicability and market competitiveness, reduce coating production costs, increase production efficiency, and enhance the company's economic benefits.

[0003] However, the realization of high-gloss black paint paste is a technical challenge, especially while maintaining high gloss, it is also necessary to ensure the paint paste's aging resistance, wear resistance and ease of construction. In the existing technology, black paint pastes often contain volatile organic compounds, which pose a potential threat to the environment and human health. Therefore, with the increasingly stringent environmental regulations and the improvement of consumers' requirements for automobile appearance quality, the development of an automotive high-gloss black paint paste that is both environmentally friendly and has excellent performance has become an urgent problem to be solved in the industry, and the development of nanotechnology has provided new possibilities for improving the performance of paint pastes. Summary of the Invention

[0004] The present invention provides a coating paste specially used for automotive high-gloss black and a preparation method thereof. The coating paste prepared by the present invention is environmentally friendly and has a glossiness of not only above 90GU, which meets the grade standard of high-gloss paint (75GU), but also exhibits very excellent wear resistance, corrosion resistance and aging resistance.

[0005] A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 35-70 parts of environmentally friendly polyurethane resin; 9-20 parts of melanin pigment; 8-15 parts of nano-silica filler; 2-6 parts of leveling agent; 1-2 parts defoamer; 1-3 parts of zirconium oxide nanoparticles; 3-6 parts of anti-UV microcapsules; Among them, the anti-ultraviolet microcapsules are based on the free radical polymerization mechanism, with methyl methacrylate, butyl acrylate, dispersant, emulsifier, organic-inorganic composite anti-ultraviolet agent as raw materials, and are prepared by emulsion polymerization under the initiation of ammonium persulfate.

[0006] Furthermore, the preparation method of the organic-inorganic composite anti-ultraviolet agent is: One molar equivalent of pentaerythritol triacrylate and two molar equivalents of 2,2,6,6-tetramethylpiperidinamine undergo Michael addition reaction, followed by urethanization reaction with one molar equivalent of an isocyanate silane coupling agent to obtain a hindered amine silane coupling agent. The hindered amine silane coupling agent is used to modify the surface of nano-titanium dioxide to obtain an organic-inorganic composite anti-ultraviolet agent.

[0007] Furthermore, the isocyanate silane coupling agent is 3-isocyanate propyltrimethoxysilane or isocyanate propyltriethoxysilane.

[0008] Furthermore, the melanin pigment is carbon black with a particle size of 20-50 nm.

[0009] Furthermore, the particle size of the nano-silica filler is 10-20 nm.

[0010] Furthermore, the leveling agent is any one of BYK-333 leveling agent, BYK-348 leveling agent or BYK-378 leveling agent.

[0011] Furthermore, the defoamer is any one of BYK-017 defoamer, BYK-1660 defoamer or JT-908 defoamer.

[0012] A method for preparing a special coating paste for automotive high gloss black is as follows: After evenly mixing the environmentally friendly polyurethane resin, melanin pigment, and nano-silica filler, heat to 35-45°C and mix evenly in a high-speed disperser. Then add zirconium oxide nanoparticles and anti-UV microcapsules and disperse evenly. Then add leveling agent and defoaming agent, grind, and filter to obtain the coating paste.

[0013] Beneficial effects: The present invention uses an environmentally friendly polyurethane resin, a melanin pigment, a nano-silica filler, a leveling agent, a defoaming agent, zirconium oxide nanoparticles, and anti-UV microcapsules as raw materials to prepare a coating paste. The present invention improves the workability of the coating paste by adjusting the formulation. Furthermore, by selecting an environmentally friendly polyurethane resin, the content of volatile organic compounds is reduced. Thirdly, by preparing anti-UV microcapsules and utilizing the hindered amine functional groups and nano-titanium dioxide in the anti-UV microcapsules, the coating paste is endowed with excellent UV protection, thereby preventing the coating paste coating from aging due to long-term sunlight exposure and improving the aging resistance of the coating paste. After undergoing artificial weathering aging tests, the cured coating of the coating paste exhibits no gloss loss, discoloration, or powdering. This helps the coating paste maintain good and stable performance under long-term outdoor conditions, broadening the application range of the coating paste in harsh environments. DETAILED DESCRIPTION

[0014] Experimental Example 1: 1. The preparation method of anti-ultraviolet microcapsules is as follows: 1 molar equivalent of pentaerythritol triacrylate and 2 molar equivalents of 2,2,6,6-tetramethylpiperidinamine undergo Michael addition reaction, followed by urethanization reaction with 1 molar equivalent of 3-isocyanatepropyltrimethoxysilane to obtain a hindered amine silane coupling agent; The surface of nano-titanium dioxide is modified using a hindered amine silane coupling agent to obtain an organic-inorganic composite anti-UV agent; based on the free radical polymerization mechanism, methyl methacrylate, butyl acrylate, dispersant, emulsifier, and organic-inorganic composite anti-UV agent are used as raw materials, and emulsion polymerization is carried out under the initiation of ammonium persulfate to prepare anti-UV microcapsules.

[0015] 2. The preparation method of anti-ultraviolet microcapsules comprises the following steps: Step 1: Add 3 g of pentaerythritol triacrylate to 50 mL of dimethyl sulfoxide, stir and mix well, then add 3.2 g of 2,2,6,6-tetramethylpiperidinamine, place the system at 65 ° C for 5 hours, cool naturally to room temperature, then introduce nitrogen, add 2.1 g of 3-isocyanatepropyltrimethoxysilane, stir well, add 0.1 g of dibutyltin dilaurate, heat to 70 ° C, keep the reaction for 4 hours, and cool to room temperature. Afterwards, filter, wash, and dry to obtain a hindered amine silane coupling agent; step 2, add 0.2g of hindered amine silane coupling agent to 100mL of deionized water, add hydrochloric acid dropwise, adjust the pH to 4, ultrasonically disperse for 10min, stir for 40min, then add 4g of nano titanium dioxide (rutile type, average particle size of 20nm), heat to 80°C, continue stirring for 3h, filter, wash, and dry to obtain an organic-inorganic composite anti-ultraviolet agent; Step 3: Add 0.03 g of sodium dodecylsulfonate, 0.03 g of emulsifier OP-10, and 2.5 g of an organic-inorganic composite anti-ultraviolet agent to 50 mL of deionized water, stir and mix evenly, adjust the pH to 8 with ammonia water, heat to 75 ° C, add 0.1 g of ammonium persulfate, stir for 15 minutes, add 3.5 g of methyl methacrylate and 3.5 g of butyl acrylate, keep warm and react for 5 hours. After the reaction is completed, cool to room temperature, filter under reduced pressure, wash, and dry to obtain anti-ultraviolet microcapsules.

[0016] Example 1: A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 35 parts of environmentally friendly polyurethane resin (waterborne polyurethane Bayhydrol AXP 2407); 9 parts of carbon black (particle size 20-50 nm); 8 parts of nano-silica filler (10-20nm); 2 parts BYK-378 leveling agent; 1 part BYK-017 defoamer; 1 part of zirconium oxide nanoparticles (particle size 30 nm); 3 parts of anti-UV microcapsules (prepared in Experimental Example 1); A special coating paste for automotive high gloss black, the preparation method of which is as follows: After uniformly mixing the environmentally friendly polyurethane resin, carbon black and nano-silica filler, the temperature was raised to 40°C and the mixture was fully dispersed in a high-speed disperser at a speed of 2000 r / min for 10 minutes. Zirconium oxide nanoparticles and anti-UV microcapsules were added and dispersed at a speed of 3000 r / min for 60 minutes. BYK-378 leveling agent and BYK-017 defoaming agent were then added and dispersed at a speed of 2000 r / min for 10 minutes. The mixture was ground using a three-roll grinder for 20 minutes and filtered to obtain a coating paste.

[0017] Example 2: A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 40 parts of environmentally friendly polyurethane resin (water-based polyurethane Bayhydrol A XP 2407); 10 parts of carbon black (particle size 20-50 nm); 9 parts of nano-silica filler (10-20nm); 3 parts of leveling agent (BYK-378); 1 part defoamer (BYK-017); 1 part of zirconium oxide nanoparticles (particle size 30 nm); 3 parts of anti-UV microcapsules (prepared in Experimental Example 1); A special coating paste for automotive high gloss black, the preparation method of which is as follows: After uniformly mixing the environmentally friendly polyurethane resin, carbon black and nano-silica filler, the temperature was raised to 40°C and the mixture was fully dispersed in a high-speed disperser at a speed of 2000 r / min for 10 minutes. Zirconium oxide nanoparticles and anti-UV microcapsules were added and dispersed at a speed of 3000 r / min for 60 minutes. BYK-378 leveling agent and BYK-017 defoaming agent were then added and dispersed at a speed of 2000 r / min for 10 minutes. The mixture was ground using a three-roll grinder for 20 minutes and filtered to obtain a coating paste.

[0018] Example 3: A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 45 parts of environmentally friendly polyurethane resin (waterborne polyurethane Bayhydrol A XP 2407); 11 parts of carbon black (particle size 20-50 nm); 10 parts of nano-silica filler (10-20nm); 3 parts of leveling agent (BYK-378); 1 part defoamer (BYK-017); 2 parts of zirconium oxide nanoparticles (particle size 30 nm); 4 parts of anti-UV microcapsules (prepared in Experimental Example 1); A special coating paste for automotive high gloss black, the preparation method of which is as follows: After uniformly mixing the environmentally friendly polyurethane resin, carbon black and nano-silica filler, the temperature was raised to 40°C and the mixture was fully dispersed in a high-speed disperser at a speed of 2000 r / min for 10 minutes. Zirconium oxide nanoparticles and anti-UV microcapsules were added and dispersed at a speed of 3000 r / min for 60 minutes. BYK-378 leveling agent and BYK-017 defoaming agent were then added and dispersed at a speed of 2000 r / min for 10 minutes. The mixture was ground using a three-roll grinder for 20 minutes and filtered to obtain a coating paste.

[0019] Example 4: A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 50 parts of environmentally friendly polyurethane resin (water-based polyurethane Bayhydrol A XP 2407); 13 parts of carbon black (particle size 20-50 nm); 11 parts of nano-silica filler (10-20 nm); 4 parts of leveling agent (BYK-378); 1.5 parts defoamer (BYK-017); 2 parts of zirconium oxide nanoparticles (particle size 30 nm); 4 parts of anti-UV microcapsules (prepared in Experimental Example 1); A special coating paste for automotive high gloss black, the preparation method of which is as follows: After uniformly mixing the environmentally friendly polyurethane resin, carbon black and nano-silica filler, the temperature was raised to 40°C and the mixture was fully dispersed in a high-speed disperser at a speed of 2000 r / min for 10 minutes. Zirconium oxide nanoparticles and anti-UV microcapsules were added and dispersed at a speed of 3000 r / min for 60 minutes. BYK-378 leveling agent and BYK-017 defoaming agent were then added and dispersed at a speed of 2000 r / min for 10 minutes. The mixture was ground using a three-roll grinder for 20 minutes and filtered to obtain a coating paste.

[0020] Example 5: A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 55 parts of environmentally friendly polyurethane resin (waterborne polyurethane Bayhydrol A XP 2407); 15 parts of carbon black (particle size 20-50 nm); 12 parts of nano-silica filler (10-20nm); 4 parts of leveling agent (BYK-378); 1.5 parts defoamer (BYK-017); 2.5 parts of zirconium oxide nanoparticles (particle size 30 nm); 5 parts of anti-UV microcapsules (prepared in Experimental Example 1); A special coating paste for automotive high gloss black, the preparation method of which is as follows: After uniformly mixing the environmentally friendly polyurethane resin, carbon black and nano-silica filler, the temperature was raised to 40°C and the mixture was fully dispersed in a high-speed disperser at a speed of 2000 r / min for 10 minutes. Zirconium oxide nanoparticles and anti-UV microcapsules were added and dispersed at a speed of 3000 r / min for 60 minutes. BYK-378 leveling agent and BYK-017 defoaming agent were then added and dispersed at a speed of 2000 r / min for 10 minutes. The mixture was ground using a three-roll grinder for 20 minutes and filtered to obtain a coating paste.

[0021] Example 6: A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 60 parts of environmentally friendly polyurethane resin (waterborne polyurethane Bayhydrol A XP 2407); 16 parts of carbon black (particle size 20-50 nm); 13 parts of nano-silica filler (10-20 nm); 5 parts of leveling agent (BYK-378); 2 parts defoamer (BYK-017); 2.5 parts of zirconium oxide nanoparticles (particle size 30 nm); 5 parts of anti-UV microcapsules (prepared in Experimental Example 1); A special coating paste for automotive high gloss black, the preparation method of which is as follows: After uniformly mixing the environmentally friendly polyurethane resin, carbon black and nano-silica filler, the temperature was raised to 40°C and the mixture was fully dispersed in a high-speed disperser at a speed of 2000 r / min for 10 minutes. Zirconium oxide nanoparticles and anti-UV microcapsules were added and dispersed at a speed of 3000 r / min for 60 minutes. BYK-378 leveling agent and BYK-017 defoaming agent were then added and dispersed at a speed of 2000 r / min for 10 minutes. The mixture was ground using a three-roll grinder for 20 minutes and filtered to obtain a coating paste.

[0022] Example 7: A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 65 parts of environmentally friendly polyurethane resin (waterborne polyurethane Bayhydrol AXP 2407); 18 parts of carbon black (particle size 20-50 nm); 14 parts of nano-silica filler (10-20nm); 5 parts of leveling agent (BYK-378); 2 parts defoamer (BYK-017); 3 parts of zirconium oxide nanoparticles (particle size 30 nm); 6 parts of anti-UV microcapsules (prepared in Experimental Example 1); A special coating paste for automotive high gloss black, the preparation method of which is as follows: After uniformly mixing the environmentally friendly polyurethane resin, carbon black and nano-silica filler, the temperature was raised to 40°C and the mixture was fully dispersed in a high-speed disperser at a speed of 2000 r / min for 10 minutes. Zirconium oxide nanoparticles and anti-UV microcapsules were added and dispersed at a speed of 3000 r / min for 60 minutes. BYK-378 leveling agent and BYK-017 defoaming agent were then added and dispersed at a speed of 2000 r / min for 10 minutes. The mixture was ground using a three-roll grinder for 20 minutes and filtered to obtain a coating paste.

[0023] Example 8: A special coating paste for automotive high-gloss black, comprising the following raw materials in parts by weight: 70 parts of environmentally friendly polyurethane resin (water-based polyurethane Bayhydrol AXP 2407); 20 parts of carbon black (particle size 20-50 nm); 15 parts of nano-silica filler (10-20 nm); 6 parts of leveling agent (BYK-378); 2 parts of defoaming agent (BYK-017); 3 parts of zirconium oxide nanoparticles (particle size 30 nm); 6 parts of anti-ultraviolet microcapsules (prepared in Experimental Example 1); A coating color paste special for automobile high-gloss black, the preparation method thereof is as follows: After the environmentally friendly polyurethane resin, carbon black and nano-silica filler are uniformly mixed, the temperature is raised to 40℃, and then they are fully dispersed in a high-speed dispersion machine at a speed of 2000 r / min for 10 min, zirconium oxide nanoparticles and anti-ultraviolet microcapsules are added and dispersed at a speed of 3000 r / min for 60 min, then BYK-378 leveling agent and BYK-017 defoaming agent are added and dispersed at a speed of 2000 r / min for 10 min, and then a three-roll grinding machine is used for grinding for 20 min, and then filtration is performed to obtain the coating color paste.

[0024] Comparative Example 1 A coating color paste special for automobile high-gloss black, the preparation method thereof is as follows: 55 parts of environmentally friendly polyurethane resin (water-based polyurethane Bayhydrol AXP 2407); 15 parts of carbon black (particle size 20-50 nm); 12 parts of nano-silica filler (10-20 nm); 4 parts of leveling agent (BYK-378); 1.5 parts of defoaming agent (BYK-017); 2.5 parts of zirconium oxide nanoparticles (particle size 30 nm); A coating color paste special for automobile high-gloss black, the preparation method thereof is as follows: After the environmentally friendly polyurethane resin, carbon black and nano-silica filler are uniformly mixed, the temperature is raised to 40℃, and then they are fully dispersed in a high-speed dispersion machine at a speed of 2000 r / min for 10 min, zirconium oxide nanoparticles and anti-ultraviolet microcapsules are added and dispersed at a speed of 3000 r / min for 60 min, then BYK-378 leveling agent and BYK-017 defoaming agent are added and dispersed at a speed of 2000 r / min for 10 min, and then a three-roll grinding machine is used for grinding for 20 min, and then filtration is performed to obtain the coating color paste.

[0025] Performance detection: After 8 parts by weight of Bayhydur 304 curing agent was added into 2 parts by weight of propylene glycol methyl ether acetate and mixed uniformly, 55 parts by weight of the paint color paste prepared in Examples 1-8 and Comparative Example 1 was added thereinto and stirred at a stirring rate of 1000 r / min for 3 min, the paint color paste was coated on a glass plate with a size of 150 mm x 100 mm x 2 mm, the coating film thickness was 55 μm, and the coating layer was formed after curing at 60℃ for 40 min.

[0026] I. Glossiness test According to GB / T 9754-2007 standard, the 60° mirror surface glossiness of the coating layer was tested by using a bench mirror glossiness meter, and the results are shown in Table 1: Table 1 Glossiness test results of paint color paste serial number Glossiness degree / GU Example 1 95 Example 2 93 Example 3 95 Example 4 94 Example 5 96 Example 6 95 Example 7 96 Example 8 95 II. Abrasion resistance test The abrasion resistance of the coating layer was tested by using an abrasion tester, 120# sandpaper was pasted on a rubber sand wheel, and after sanding for 600 times, the appearance state of the coating layer was observed, and the results are shown in Table 2: Table 2 Abrasion resistance test results of paint color paste serial number Coating status after sanding 600 times Example 1 No obvious wear Example 2 No obvious wear Example 3 No obvious wear Example 4 No obvious wear Example 5 No obvious wear Example 6 No obvious wear Example 7 No obvious wear Example 8 No obvious wear III. Acid and alkali resistance test The coating layer was immersed in a 50% concentration sodium hydroxide solution and a 5% concentration sulfuric acid solution for 1 d, and whether the coating layer appeared light loss, discoloration, spots and peeling was observed, and the results are shown in Table 3: Table 3 Acid and alkali resistance test results of paint color paste IV. Artificial weathering resistance test According to GB / T 1865-2009 standard, the test was carried out by using a QUV aging test box, the coating layer was placed in the test box, the temperature was controlled at 55℃, the light source was turned on, and the continuous irradiation was carried out for 2000 h, after the end, the state of the coating layer was observed, and the aging resistance of the coating layer was evaluated, and the results are shown in Table 4: Table 4 Aging resistance test results of paint color paste From the experimental data in Tables 1-4, the following conclusions can be drawn: The paint color paste prepared in the application not only has a glossiness of more than 90GU, all reaching the grade standard of high gloss paint (75GU), but also has very excellent wear resistance, corrosion resistance and aging resistance.

Claims

1. A special coating paste for automotive high gloss black, characterized in that: The invention comprises the following raw materials in parts by weight: 35-70 parts of environmentally friendly polyurethane resin; 9-20 parts of melanin pigment; 8-15 parts of nano-silica filler; 2-6 parts of leveling agent; 1-2 parts defoamer; 1-3 parts of zirconium oxide nanoparticles; 3-6 parts of anti-UV microcapsules; Among them, the anti-ultraviolet microcapsules are based on the free radical polymerization mechanism, with methyl methacrylate, butyl acrylate, dispersant, emulsifier, organic-inorganic composite anti-ultraviolet agent as raw materials, and are prepared by emulsion polymerization under the initiation of ammonium persulfate.

2. The special coating paste for automotive high gloss black according to claim 1, characterized in that: The preparation method of the organic-inorganic composite anti-ultraviolet agent is as follows: 1 molar equivalent of pentaerythritol triacrylate and 2 molar equivalents of 2,2,6,6-tetramethylpiperidinamine undergo Michael addition reaction, followed by urethanization reaction with 1 molar equivalent of an isocyanate silane coupling agent to obtain a hindered amine silane coupling agent; The surface of nano-titanium dioxide is modified by using a hindered amine silane coupling agent to obtain an organic-inorganic composite anti-ultraviolet agent.

3. The special coating paste for automotive high gloss black according to claim 2, characterized in that: The isocyanate silane coupling agent is 3-isocyanate propyl trimethoxy silane or isocyanate propyl triethoxy silane.

4. The special coating paste for automotive high gloss black according to claim 1, characterized in that: The melanin pigment is carbon black with a particle size of 20-50 nm.

5. The special coating paste for automotive high gloss black according to claim 1, characterized in that: The particle size of the nano-silicon dioxide filler is 10-20 nm.

6. The special coating paste for automotive high gloss black according to claim 1, characterized in that: The leveling agent is any one of BYK-333 leveling agent, BYK-348 leveling agent or BYK-378 leveling agent.

7. The special coating paste for automotive high gloss black according to claim 1, characterized in that: The defoamer is any one of BYK-017 defoamer, BYK-1660 defoamer or JT-908 defoamer.

8. A method for preparing the automotive high gloss black coating paste according to any one of claims 1 to 7, characterized in that: The preparation method is: After evenly mixing the environmentally friendly polyurethane resin, melanin pigment, and nano-silica filler, heat to 35-45°C and mix evenly in a high-speed disperser. Then add zirconium oxide nanoparticles and anti-UV microcapsules and disperse evenly. Then add leveling agent and defoaming agent, grind, and filter to obtain the coating paste.

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