A luminescent powder coating and a method for producing the same

Abstract

The application discloses a luminescent powder coating and a preparation method thereof, and belongs to the field of powder coating preparation. The carboxyl-terminated polyester resin is added to provide superior mechanical properties for the powder coating, the fluorine-containing acrylic resin is easy to coat the luminescent material, and the luminescent material can maintain stable performance in long-term outdoor exposure and is not prone to fading, pulverization and aging problems, so the luminescent material coated by the fluorine-containing acrylic resin is added to the powder coating system, and the weather resistance of the luminescent material can be obviously improved. The bonding process treatment enables the luminescent material to be arranged firmly and uniformly and orderly on the surface of the coating film, so that the luminescence is more uniform. Overall, through the use of the compounding of components, the components are synergistically combined, so that more excellent performance is exhibited. Compared with traditional powder coatings added with fluorescent agents, the powder coating has better weather resistance, high afterglow brightness, can be effectively used in outdoor places, can play a decorative and warning effect, has excellent overall stability, and still maintains excellent luminescent performance after long-time storage and use.

Description

Technical Field

[0001] This invention relates to the field of powder coating preparation, and more specifically, to a luminescent powder coating and its preparation method. Background Technology

[0002] With social development and the improvement of people's living standards, the performance and functional requirements of coatings are becoming increasingly diversified. Powder coatings, a type of coating with 100% solid components, differ from traditional solvent-based and water-based coatings. Their VOC (volatile organic compound) content is almost zero, resulting in no solvent pollution and making them more energy-efficient and environmentally friendly. Luminescent coatings are one of the fastest-growing high-tech functional materials internationally. These coatings are made by mixing luminescent materials, organic resins, organic solvents, inorganic pigments, fillers, and additives in specific proportions. They can absorb and store light energy under sunlight or lamplight, and then slowly release the absorbed energy as visible light in the dark, with a luminescence time that can last for more than 10 hours. Due to their ability to emit light in dark environments, luminescent coatings have broad application prospects in areas such as traffic safety, building decoration, and fire emergency response. In existing technologies, powder coatings are given a certain luminescent effect by adding alkaline earth metal aluminate luminescent materials. Due to the different ratios of strontium oxide and aluminum oxide, the wavelength and afterglow time of fluorescence are also different. By changing the content of strontium oxide and aluminum oxide, the doping amount of europium and dysprosium, and by partially or completely replacing strontium oxide with calcium oxide, magnesium oxide, barium oxide, etc., or by adding them in combination, a series of rare earth activated alkaline earth metal aluminate luminescent coatings with different initial luminescence intensities and afterglow times can be obtained. However, the luminescent coatings still have the problems of short luminescence time, low luminescence intensity and poor stability, which limits their application range. Summary of the Invention

[0003] The purpose of this invention is to provide a luminescent powder coating and its preparation method to solve the problems of short luminescence time, low luminescence intensity, and poor stability that still exist in luminescent coatings.

[0004] To achieve the above objectives, the present invention provides a luminescent powder coating comprising the following raw materials in parts by weight: 55-70 parts of carboxyl-terminated polyester resin, 5-10 parts of fluorinated acrylic resin, 4-5.3 parts of triglycidyl isocyanate, 10-20 parts of filler, 10-20 parts of luminescent material, 0.5-2 parts of leveling agent, 0.5-2 parts of brightener, 0.5-1 part of carbon nanotubes, 0.2-0.3 parts of anti-scratch agent, 0.2-0.5 parts of benzoin, 0.5-2 parts of defoamer, 0.5-2 parts of antioxidant, 0-3.0 parts of pigment, 0.1-0.2 parts of desiccant, 0.1-0.3 parts of bonding agent, and 0.3-0.5 parts of silica.

[0005] Furthermore, the carboxyl-terminated polyester resin has an acid value of 32 mg KOH / g to 38 mg KOH / g, a viscosity at 200℃ (mPa.s) of 1500 to 2500, and a glass transition temperature of 67℃ to 70℃.

[0006] Furthermore, the filler is at least one of calcium carbonate, mica powder, and barium sulfate.

[0007] Furthermore, the luminescent material includes a matrix and an activator, and the activator accounts for 10% to 30% of the mass of the matrix.

[0008] Furthermore, the activator is a rare earth element.

[0009] Furthermore, the matrix is ​​one or a mixture of two of aluminates and silicates.

[0010] Furthermore, the carbon nanotubes have an electrical conductivity >150s / cm and a length of 10~20um, and are obtained by rolling up graphene sheets.

[0011] Furthermore, the anti-scratch agent is at least one of micronized polypropylene wax, PTFE-modified PE wax, and PP wax.

[0012] In addition, the present invention also provides a method for preparing a luminescent powder coating, the method comprising the following steps:

[0013] The luminescent material is added to a drum ball mill for ball milling. Then, the ball-milled luminescent material and silicon dioxide are added to a mixing device for high-speed airflow impact treatment to obtain mixture A. Then, mixture A, carbon nanotubes and fluorinated acrylic resin are added to a grinding device for stirring, grinding and coating treatment to obtain mixture B.

[0014] Carboxyl-terminated polyester resin, triglycidyl isocyanate, filler, leveling agent, gloss agent, scratch-resistant agent, benzoin, defoamer, antioxidant, and pigment are added to a mixing tank for premixing; then, mixture C is obtained by melt extrusion, cooling, and ACM milling.

[0015] Mixture B, mixture C, and bonding agent are mixed and bonded. Then, a desiccant is added and the mixture is sieved through a 160-180 mesh screen to obtain a luminescent powder coating.

[0016] Furthermore, the conditions for melt extrusion are: screw speed of 40HZ~45HZ, melting zone temperature of 120℃~125℃, and mixing zone temperature of 130℃~135℃.

[0017] Furthermore, the bonding process conditions are as follows: bonding temperature is 65℃~68℃, heating speed is 900rpm~1000rpm, bonding speed is 600rpm~700rpm, cooling speed is 400rpm~500rpm, cold water temperature is 17℃~19℃, hot water temperature is 70℃~75℃, and the bonding time is 300s~500s.

[0018] The luminescent powder coating, its preparation method, and its application provided by the above technical solution have the following advantages compared with the prior art:

[0019] The end-carboxyl polyester resin in this invention has low viscosity and excellent leveling properties, while also providing superior mechanical properties for the coating. The fluorine atoms in the fluorinated acrylic resin have high electronegativity and small atomic radii, resulting in low surface energy, making it easier to coat the luminescent material. Furthermore, the luminescent material after ball milling has a larger specific surface area, further promoting the coating effect of the fluorinated acrylic resin. The presence of fluorine atoms gives the resin good UV resistance and antioxidant properties. The fluorinated acrylic resin can maintain its stable performance during long-term outdoor exposure, and is not prone to fading, chalking, or aging. The added carbon nanotubes give the coated luminescent material good conductivity, which facilitates the adsorption of the luminescent material onto the substrate surface during powder coating, effectively enhancing the luminescence intensity of the luminescent powder coating. Adding the coated luminescent material to the powder coating system significantly improves its weather resistance, allowing for stable outdoor use and significant durability. The low surface energy of the coating resin allows the luminescent material to float to the coating surface as much as possible during the powder coating melting process, increasing the luminescent area.

[0020] This invention utilizes a bonding process to ensure that the treated luminescent material firmly adheres to the surface of powder particles. After spraying and curing, the luminescent material is evenly and orderly arranged on the surface of the coating, resulting in more uniform luminescence. Simultaneously, the coating treatment significantly increases the content of the luminescent material in the powder coating, avoiding the problem of poor leveling caused by excessive addition. The grinding discs and columns of the ACM mill involved in the preparation of the luminescent powder coating, as well as the bonding mixing vessel, undergo carburizing treatment. This increases the Mohs hardness and wear resistance of the mill and bonding machine, preventing iron metal precipitation from surface damage during high-speed operation from contaminating the luminescent material and causing phenomena such as dimming and uneven luminescence in the luminescent powder coating.

[0021] This invention utilizes a compounding of components, with synergistic effects among them, resulting in superior performance. Compared to traditional powder coatings containing fluorescent agents, it exhibits better weather resistance, higher afterglow brightness, and is effectively suitable for outdoor use, serving both decorative and warning purposes. It also demonstrates excellent overall stability, maintaining superior luminescence performance even after prolonged storage and use. Furthermore, the luminescent material particles of this invention are larger, resulting in higher afterglow brightness. Encapsulation with a low-surface-energy fluorinated acrylic resin allows them to effectively float on the powder coating film, significantly enhancing the coverage of the luminescent material and further improving afterglow brightness. The luminescent material, composed of a matrix and an activator, provides enhanced decorative effects. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] According to one embodiment of the present invention, a luminescent powder coating comprises the following raw materials in parts by weight: 55-70 parts of carboxyl-terminated polyester resin, 5-10 parts of fluorinated acrylic resin, 4-5.3 parts of triglycidyl isocyanate, 10-20 parts of filler, 10-20 parts of luminescent material, 0.5-2 parts of leveling agent, 0.5-2 parts of brightener, 0.5-1 parts of carbon nanotubes, 0.2-0.3 parts of anti-scratch agent, 0.2-0.5 parts of benzoin, 0.5-2 parts of defoamer, 0.5-2 parts of antioxidant, 0-3.0 parts of pigment, 0.1-0.2 parts of desiccant, 0.1-0.3 parts of bonding agent, and 0.3-0.5 parts of silica.

[0025] In one embodiment, the carboxyl-terminated polyester resin has an acid value of 32 mg KOH / g to 38 mg KOH / g, a viscosity of 1500 to 2500 mPa·s at 200°C, and a glass transition temperature of 67°C to 70°C.

[0026] In one embodiment, the fluorinated acrylic resin is a synthetic resin in which fluorine is introduced into the acrylic resin structure.

[0027] In one embodiment, the filler is at least one of calcium carbonate, mica powder, and barium sulfate.

[0028] In one embodiment, the luminescent material includes a matrix and an activator, wherein the activator accounts for 10% to 30% of the mass of the matrix.

[0029] In one embodiment, the activator is a rare earth element.

[0030] In one embodiment, the rare earth element is at least one of europium and dysprosium.

[0031] In one embodiment, the matrix is ​​one or a mixture of two of aluminates and silicates.

[0032] In one embodiment, the carbon nanotubes have an electrical conductivity >150 s / cm and a length of 10~20 μm, and are obtained by rolling up graphene sheets.

[0033] In one embodiment, the matrix and activator are mixed and then treated at a temperature of 45°C to 65°C for 20 to 30 minutes to obtain a luminescent material.

[0034] In one embodiment, the anti-scratch agent is at least one of micronized polypropylene wax, PTFE-modified PE wax, and PP wax.

[0035] In one embodiment, the leveling agent is a polyester-modified silicone leveling agent.

[0036] In one embodiment, the defoamer is a polyether-modified silicone defoamer.

[0037] In one embodiment, the antioxidant is a hindered phenolic antioxidant.

[0038] In one embodiment, the median particle size of the silicon dioxide is 7 nm to 10 nm.

[0039] In one embodiment, the desiccant is imported alumina C, a fine-particle pure alumina with a surface area (m2 / g): 100±10, an average particle size (nm): 10-13, and an Al2O3 content of ≥99.7%.

[0040] In one embodiment, the bonding agent is a white, extremely fine powder, the main component of which is a complex amide wax, with a solid content >99.5% and a particle size (D). 50 The thickness is 2-3 μm. Adding bonding additives in the bonding process helps prevent agglomeration and improves the bonding effect of metal powder.

[0041] In one embodiment, the surfaces of the grinding disc and grinding column of the ACM grinding machine, as well as the bonded stirring tank, undergo carburizing treatment, with a carburized hardened layer thickness of 2-6 mm. The specific processing involves placing the metal and carburizing agent together in a sealed cavity, activating the metal surface using heating and vacuum methods, and then allowing carbon to penetrate the metal matrix through decomposition, absorption, and diffusion processes.

[0042] In addition, the present invention also provides a method for preparing a luminescent powder coating, the method comprising the following steps:

[0043] The luminescent material is added to a drum ball mill for ball milling. The ball-milled luminescent material and silicon dioxide are added to a mixing device for high-speed airflow impact treatment to obtain mixture A. Then, mixture A, carbon nanotubes and fluorinated acrylic resin are added to a grinding device for stirring, grinding and coating treatment to obtain mixture B.

[0044] Carboxyl-terminated polyester resin, triglycidyl isocyanate, filler, leveling agent, gloss agent, scratch-resistant agent, benzoin, defoamer, antioxidant, and pigment are added to a mixing tank for premixing; then, mixture C is obtained by melt extrusion, cooling, and ACM milling.

[0045] Mixture B, mixture C, and bonding agent are mixed and bonded. Then, a desiccant is added and the mixture is sieved through a 160-180 mesh screen to obtain a luminescent powder coating.

[0046] In one embodiment, the conditions for melt extrusion are: screw speed of 40 Hz to 45 Hz, melting zone temperature of 120 ℃ to 125 ℃, and mixing zone temperature of 130 ℃ to 135 ℃.

[0047] In one embodiment, the grinding mill settings during the ACM grinding process are as follows: main grinding frequency 30HZ~35HZ, auxiliary grinding frequency 20HZ~30HZ, and feeding frequency 18HZ~25HZ.

[0048] In one embodiment, the bonding process conditions are as follows: bonding temperature is 65℃~68℃, heating speed is 900rpm~1000rpm, bonding speed is 600rpm~700rpm, cooling speed is 400rpm~500rpm, cold water temperature is 17℃~19℃, hot water temperature is 70℃~75℃, and the bonding time is 300s~500s.

[0049] This invention utilizes a combination of components, which work synergistically to achieve superior performance. Compared to traditional powder coatings with added fluorescent agents, it exhibits better weather resistance, higher afterglow brightness, and can be effectively used in outdoor settings for both decorative and warning purposes. It also demonstrates excellent overall stability, maintaining superior luminescence performance even after prolonged storage and use.

[0050] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments.

[0051] It should be noted that all raw materials listed below are by weight. The surfaces of the grinding disc and grinding column of the ACM grinder in the following examples, as well as the bonded mixing tank, have undergone carburizing treatment.

[0052] Example 1:

[0053] A method for preparing a luminescent powder coating includes the following steps:

[0054] Aluminate and europium (20% by mass of the aluminate) were mixed and treated at 50°C for 25 minutes to obtain a luminescent material.

[0055] Sixteen parts of luminescent material were added to a drum ball mill for ball milling. The ball-milled luminescent material and 0.4 parts of silica were added to a mixing device for high-speed airflow impact treatment to obtain mixture A. Then, mixture A, 0.8 parts of carbon nanotubes and 8 parts of fluorinated acrylic resin were added to a grinding device for stirring, grinding and coating treatment to obtain mixture B.

[0056] 65 parts of carboxyl-terminated polyester resin, 4.9 parts of triglycidyl isocyanate, 15 parts of calcium carbonate, 1 part of polyester-modified silicone leveling agent, 0.5 parts of brightener, 0.2 parts of micronized polypropylene wax, 0.2 parts of benzoin, 0.8 parts of polyether-modified silicone defoamer, 1 part of hindered phenolic antioxidant, and 1 part of pigment were added to a mixing tank for premixing. Then, the mixture was melt-extruded under the following conditions: screw speed 45 Hz, melting zone temperature 120 ℃, mixing zone temperature 130 ℃, cooled, and then subjected to ACM grinding. During the ACM grinding process, the grinding mill settings were: main mill frequency 30 Hz, auxiliary mill frequency 20 Hz, and feeding frequency 18 Hz, to obtain mixture C.

[0057] Mixture B, mixture C, and bonding additives are mixed and subjected to a bonding process under the following conditions: bonding temperature of 65°C, heating speed of 900 rpm, bonding speed of 600 rpm, cooling speed of 400 rpm, cold water temperature of 17°C, hot water temperature of 70°C, and bonding time of 300 s. Then, imported alumina C is added, and after mixing, the mixture is sieved through a 160-mesh screen to obtain a luminescent powder coating.

[0058] Example 2:

[0059] A method for preparing a luminescent powder coating includes the following steps:

[0060] Aluminate and europium (18% by mass of the aluminate) were mixed and treated at 60°C for 30 minutes to obtain a luminescent material.

[0061] Nineteen parts of luminescent material were added to a drum ball mill for ball milling. The ball-milled luminescent material and 0.5 parts of silica were added to a mixing device for high-speed airflow impact treatment to obtain mixture A. Then, mixture A, 0.8 parts of carbon nanotubes and 8 parts of fluorinated acrylic resin were added to a grinding device for stirring, grinding and coating treatment to obtain mixture B.

[0062] 67 parts of carboxyl-terminated polyester resin, 5 parts of triglycidyl isocyanurate, 17 parts of calcium carbonate, 1 part of polyester-modified silicone leveling agent, 0.5 parts of brightener, 0.3 parts of micronized polypropylene wax, 0.5 parts of benzoin, 1 part of polyether-modified silicone defoamer, 0.5 parts of hindered phenolic antioxidant, and 1 part of pigment were added to a mixing tank for premixing. Then, the mixture was melt-extruded under the following conditions: screw speed 42 Hz, melting zone temperature 125 ℃, mixing zone temperature 132 ℃, cooled, and then subjected to ACM grinding. During the ACM grinding process, the grinding mill settings were: main mill frequency 35 Hz, auxiliary mill frequency 30 Hz, and feeding frequency 20 Hz, to obtain mixture C.

[0063] Mixture B, mixture C, and bonding additives are mixed and subjected to a bonding process under the following conditions: bonding temperature of 66°C, heating speed of 1000 rpm, bonding speed of 700 rpm, cooling speed of 500 rpm, cold water temperature of 19°C, hot water temperature of 75°C, and bonding time of 300 s. Then, imported alumina C is added, and after mixing, the mixture is sieved through a 160-mesh screen to obtain a luminescent powder coating.

[0064] Example 3:

[0065] A method for preparing a luminescent powder coating includes the following steps:

[0066] Aluminate and dysprosium at a mass percentage of 20% of the aluminate were mixed and treated at 60°C for 30 minutes to obtain a luminescent material.

[0067] Twenty parts of luminescent material were added to a drum ball mill for ball milling. The ball-milled luminescent material and 0.5 parts of silica were added to a mixing device for high-speed airflow impact treatment to obtain mixture A. Then, mixture A, 0.8 parts of carbon nanotubes and 10 parts of fluorinated acrylic resin were added to a grinding device for stirring, grinding and coating treatment to obtain mixture B.

[0068] 68 parts of carboxyl-terminated polyester resin, 5.1 parts of triglycidyl isocyanate, 18 parts of calcium carbonate, 1 part of polyester-modified silicone leveling agent, 0.8 parts of brightener, 0.3 parts of micronized polypropylene wax, 0.4 parts of benzoin, 0.8 parts of polyether-modified silicone defoamer, 0.7 parts of hindered phenolic antioxidant, and 1 part of pigment were added to a mixing tank for premixing. Then, the mixture was melt-extruded under the following conditions: screw speed 45 Hz, melting zone temperature 125 ℃, mixing zone temperature 135 ℃, cooled, and then subjected to ACM grinding. During the ACM grinding process, the mill settings were: main mill frequency 33 Hz, auxiliary mill frequency 28 Hz, and feeding frequency 22 Hz, to obtain mixture C.

[0069] Mixture B, mixture C, and bonding agent are mixed and subjected to a bonding process under the following conditions: bonding temperature 67°C, heating speed 1000 rpm, bonding speed 700 rpm, cooling speed 450 rpm, cold water temperature 19°C, hot water temperature 74°C, and bonding time 400 s. Then, imported alumina C is added, and after mixing, the mixture is sieved through a 160-mesh sieve to obtain a luminescent powder coating.

[0070] Example 4:

[0071] A method for preparing a luminescent powder coating includes the following steps:

[0072] Aluminate and dysprosium at a mass percentage of 20% of the aluminate were mixed and treated at 65°C for 30 minutes to obtain a luminescent material.

[0073] Twenty parts of luminescent material were added to a drum ball mill for ball milling. The ball-milled luminescent material and 0.5 parts of silica were added to a mixing device for high-speed airflow impact treatment to obtain mixture A. Then, mixture A, 0.8 parts of carbon nanotubes and 10 parts of fluorinated acrylic resin were added to a grinding device for stirring, grinding and coating treatment to obtain mixture B.

[0074] 70 parts of carboxyl-terminated polyester resin, 5.3 parts of triglycidyl isocyanate, 20 parts of calcium carbonate, 0.9 parts of polyester-modified silicone leveling agent, 0.6 parts of brightener, 0.3 parts of micronized polypropylene wax, 0.4 parts of benzoin, 0.8 parts of polyether-modified silicone defoamer, 0.8 parts of hindered phenolic antioxidant, and 1 part of pigment were added to a mixing tank for premixing. Then, the mixture was melt-extruded under the following conditions: screw speed 45 Hz, melting zone temperature 125 ℃, mixing zone temperature 135 ℃, cooled, and ACM milled under the following conditions: main mill frequency 35 Hz, auxiliary mill frequency 30 Hz, and feeding frequency 25 Hz, to obtain mixture C.

[0075] Mixture B, mixture C, and bonding agent are mixed and subjected to a bonding process under the following conditions: bonding temperature 68°C, heating speed 1000 rpm, bonding speed 700 rpm, cooling speed 500 rpm, cold water temperature 19°C, hot water temperature 75°C, and bonding time 500 s. Then, imported alumina C is added, and after mixing, the mixture is sieved through a 160-mesh sieve to obtain a luminescent powder coating.

[0076] Comparative Example 1:

[0077] The difference between Comparative Example 1 and Example 4 is that the luminescent material in Comparative Example 1 was not coated; otherwise, it was the same as in Example 4. Specifically, the preparation method in Comparative Example 1 included the following steps:

[0078] Aluminate and dysprosium at a mass percentage of 20% of the aluminate were mixed and treated at 65°C for 30 minutes to obtain a luminescent material.

[0079] 20 parts of luminescent material, 0.5 parts of silica, 10 parts of fluorinated acrylic resin, 70 parts of carboxyl-terminated polyester resin, 5.3 parts of triglycidyl isocyanate, 20 parts of calcium carbonate, 0.9 parts of polyester-modified silicone leveling agent, 0.6 parts of brightener, 0.8 parts of carbon nanotubes, 0.3 parts of micronized polypropylene wax, 0.4 parts of benzoin, 0.8 parts of polyether-modified silicone defoamer, 0.8 parts of hindered phenolic antioxidant, and 1 part of pigment were added to a mixing tank for premixing. Then, the mixture was melt-extruded under the following conditions: screw speed 45 Hz, melting zone temperature 125 ℃, mixing zone temperature 135 ℃, cooled, and ACM milled under the following conditions: main mill frequency 35 Hz, auxiliary mill frequency 30 Hz, and feeding frequency 25 Hz.

[0080] The mixture and bonding agent are combined and bonded together under the following conditions: bonding temperature 68°C, heating speed 1000 rpm, bonding speed 700 rpm, cooling speed 500 rpm, cold water temperature 19°C, hot water temperature 75°C, and bonding time 500 s. Then, imported alumina C is added, and after mixing, the mixture is sieved through a 160-mesh screen to obtain a luminescent powder coating.

[0081] Comparative Example 2:

[0082] The difference between Comparative Example 2 and Example 4 is that the luminescent material in Comparative Example 2 is a single dysprosium component, that is, it does not include a matrix, while the rest is the same as in Example 4.

[0083] Comparative Example 3:

[0084] The difference between Comparative Example 3 and Example 4 is that the luminescent material in Comparative Example 3 is obtained by mixing aluminate and dysprosium at a mass percentage of 5% of the aluminate at a temperature of 65°C for 30 minutes. Everything else is the same as in Example 4.

[0085] Comparative Example 4:

[0086] The difference between Comparative Example 4 and Example 4 is that in Comparative Example 4, polyester resin was used instead of fluorinated acrylic resin, while the rest was the same as in Example 4.

[0087] Comparative Example 5:

[0088] The difference between Comparative Example 5 and Example 4 is that in Comparative Example 5, epoxy resin was used instead of carboxyl-terminated polyester resin, while the rest was the same as in Example 4.

[0089] Comparative Example 6:

[0090] The difference between Comparative Example 6 and Example 4 is that Comparative Example 6 did not undergo bonding process, but otherwise it is the same as Example 4.

[0091] Comparative Example 7:

[0092] The difference between Comparative Example 7 and Example 4 is that the bonding process conditions in Comparative Example 7 are as follows: bonding temperature is 40°C, heating speed is 1000 rpm, bonding speed is 500 rpm, cooling speed is 500 rpm, cold water temperature is 15°C, hot water temperature is 55°C, and the bonding time is 200 s. Everything else is the same as in Example 4.

[0093] Comparative Example 8:

[0094] The difference between Comparative Example 8 and Example 4 is that no luminescent material was added in Comparative Example 8, but otherwise it is the same as Example 4.

[0095] Comparative Example 9:

[0096] The difference between Comparative Example 9 and Example 4 is that the proportions of the raw materials used in Comparative Example 9 are different, while the rest are the same as in Example 4. The proportions of the raw materials used in Comparative Example 9 are as follows: 50 parts of carboxyl-terminated polyester resin, 3 parts of fluorinated acrylic resin, 1 part of triglycidyl isocyanate, 5 parts of filler, 15 parts of luminescent material, 0.5 parts of leveling agent, 0.5 parts of brightener, 0.2 parts of anti-scratch agent, 0.2 parts of benzoin, 0.5 parts of defoamer, 0.5 parts of antioxidant, 1 part of pigment, 0.1 parts of desiccant, 0.3 parts of bonding agent, and 0.1 parts of silica.

[0097] The performance of the luminescent powder coatings prepared in Examples 1-4 and the powder coatings prepared in Comparative Examples 1-9 was tested.

[0098] I. Mechanical properties are in accordance with GB / T5237.4-2017, and the test results are shown in Table 1 below.

[0099] Table 1: Mechanical Properties

[0100]

[0101] As can be seen from the data analysis in Table 1, after optimizing the preparation raw materials and the ratio of the raw materials, this application obtains a coating film with significantly improved mechanical properties.

[0102] II. Aging Resistance Test: The UVB lamp test conditions were conducted according to German standard GSBAL 631.2017, and the xenon lamp test conditions were conducted according to national standard GB / T1865-2009. The test results are shown in Table 2 below.

[0103] Table 2: Results of Aging Resistance Test

[0104]

[0105] As can be seen from the data analysis in Table 2, the coating film formed by the luminescent powder coating of this application has excellent gloss retention and uniform appearance color.

[0106] III. Brightness test, test conditions and test results are shown in Table 3 below.

[0107] Table 3: Brightness Test Results

[0108]

[0109] The data analysis in Table 3 shows that the interaction between the raw materials, the ratio of raw materials, and the process of this application results in high afterglow brightness, which can be effectively used in outdoor places and can serve as decoration and warning. The overall stability is excellent, and it still maintains excellent luminescent performance after long-term storage and use.

[0110] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A luminescent powder coating, characterized in that, The luminescent powder coating comprises the following raw materials in parts by weight: 55-70 parts of carboxyl-terminated polyester resin, 5-10 parts of fluorinated acrylic resin, 4-5.3 parts of triglycidyl isocyanate, 10-20 parts of filler, 10-20 parts of luminescent material, 0.5-2 parts of leveling agent, 0.5-2 parts of gloss agent, 0.5-1 part of carbon nanotubes, 0.2-0.3 parts of anti-scratch agent, 0.2-0.5 parts of benzoin, 0.5-2 parts of defoamer, 0.5-2 parts of antioxidant, 0-3.0 parts of pigment, 0.1-0.2 parts of desiccant, 0.1-0.3 parts of bonding agent, and 0.3-0.5 parts of silica; The luminescent material includes a matrix and an activator, wherein the activator accounts for 10% to 30% of the mass of the matrix; the activator is a rare earth element; the matrix is ​​one or a mixture of two aluminates and silicates. The method for preparing the luminescent powder coating includes the following steps: The luminescent material is added to a drum ball mill for ball milling. Then, the ball-milled luminescent material and silicon dioxide are added to a mixing device for high-speed airflow impact treatment to obtain mixture A. Then, mixture A, carbon nanotubes and fluorinated acrylic resin are added to a grinding device for stirring, grinding and coating treatment to obtain mixture B. Carboxyl-terminated polyester resin, triglycidyl isocyanate, filler, leveling agent, gloss agent, scratch-resistant agent, benzoin, defoamer, antioxidant, and pigment are added to a mixing tank for premixing; then, mixture C is obtained by melt extrusion, cooling, and ACM milling. Mixture B, mixture C, and bonding agent are mixed and subjected to a bonding process. The bonding process conditions are as follows: bonding temperature is 65℃~68℃, heating speed is 900rpm~1000rpm, bonding speed is 600rpm~700rpm, cooling speed is 400rpm~500rpm, cold water temperature is 17℃~19℃, hot water temperature is 70℃~75℃, and the bonding time is 300s~500s. After adding a desiccant and mixing, the mixture is sieved through a 160-180 mesh screen to obtain a luminescent powder coating.

2. The luminescent powder coating according to claim 1, characterized in that, The carboxyl-terminated polyester resin has an acid value of 32 mg KOH / g to 38 mg KOH / g, a viscosity of 1500 to 2500 mPa·s at 200°C, and a glass transition temperature of 67°C to 70°C.

3. The luminescent powder coating according to claim 1, characterized in that, The filler is at least one of calcium carbonate, mica powder, and barium sulfate.

4. The luminescent powder coating according to claim 1, characterized in that, The carbon nanotubes have an electrical conductivity >150 S / cm and a length of 10~20 μm, and are obtained by rolling up graphene sheets.

5. The luminescent powder coating according to claim 1, characterized in that, The anti-scratch agent is at least one of micronized polypropylene wax, PTFE-modified PE wax, and PP wax.

6. A method for preparing a luminescent powder coating, characterized in that, The preparation method is used to prepare the luminescent powder coating as described in any one of claims 1 to 5, and the preparation method includes the following steps: The luminescent material is added to a drum ball mill for ball milling. Then, the ball-milled luminescent material and silicon dioxide are added to a mixing device for high-speed airflow impact treatment to obtain mixture A. Then, mixture A, carbon nanotubes and fluorinated acrylic resin are added to a grinding device for stirring, grinding and coating treatment to obtain mixture B. Carboxyl-terminated polyester resin, triglycidyl isocyanate, filler, leveling agent, gloss agent, scratch-resistant agent, benzoin, defoamer, antioxidant, and pigment are added to a mixing tank for premixing; then, mixture C is obtained by melt extrusion, cooling, and ACM milling. Mixture B, mixture C, and bonding agent are mixed and bonded. Then, a desiccant is added and the mixture is sieved through a 160-180 mesh screen to obtain a luminescent powder coating.

7. The preparation method according to claim 6, characterized in that, The conditions for melt extrusion are: the temperature of the melting zone is 120℃~125℃, and the temperature of the mixing zone is 130℃~135℃.

8. The preparation method according to claim 6, characterized in that, The bonding process conditions are as follows: bonding temperature is 65℃~68℃, heating speed is 900rpm~1000rpm, bonding speed is 600rpm~700rpm, cooling speed is 400rpm~500rpm, cold water temperature is 17℃~19℃, hot water temperature is 70℃~75℃, and the bonding time is 300s~500s.

Images