Process for the preparation of an aluminum pigment with fluorescent effect

Abstract

The application discloses a preparation method of aluminum pigment with fluorescent effect, and comprises the following steps: grafting a first coupling agent on the surface of aluminum powder to obtain pretreated aluminum powder; immersing the pretreated aluminum powder into a fluorescent solution to obtain aluminum powder combined with fluorescent material; and coating a silica layer on the surface of the aluminum powder combined with fluorescent material to obtain aluminum pigment with fluorescent effect. The application provides a preparation method of aluminum pigment with fluorescent effect, wherein the fluorescent material is firmly adsorbed on the surface of the aluminum powder through hydrogen bond and coordination bond, and then a silica layer is prepared by using the gel-sol method to coat the fluorescent material on the surface of the aluminum powder, so that the aluminum pigment with fluorescent effect and stable performance is formed.

Description

Technical Field

[0001] This invention relates to the field of aluminum pigment technology, and in particular to a method for preparing an aluminum pigment with fluorescent effects. Background Technology

[0002] With the rapid development of optoelectronic devices, high-end coatings, and smart materials, composite materials that combine luminescence with excellent physicochemical properties have become a research hotspot in the industry. Among them, fluorescent materials, with their highly efficient luminescence characteristics, are widely used in lighting displays, anti-counterfeiting marks, stress sensing, and other fields. Meanwhile, aluminum and aluminum alloys, due to their light weight, good thermal conductivity, and metallic luster, occupy an important position in industry as structural materials and functional fillers.

[0003] Existing technologies for combining fluorescent materials and aluminum powder mainly involve simple physical mixing, such as layering fluorescent coatings with aluminum powder coatings or combining phosphors with stress-luminescent properties with aluminum powder, followed by hot-pressing sintering to prepare composite materials. However, coatings formed by simply dispersing phosphors in resin suffer from significant light absorption or scattering loss by the substrate, resulting in insufficient overall brightness and short afterglow time. While some fluorescent materials are combined with aluminum, the bonding is often too weak, and both materials are directly exposed to the external environment, leading to poor weather resistance. Furthermore, while some fluoride-based red phosphors exhibit excellent luminescence performance, their inherent physicochemical properties result in poor stability in humid and hot environments, susceptibility to deliquescence, and rapid decay of luminescence efficiency, severely limiting their application in harsh environments. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method for preparing an aluminum pigment with fluorescent effect. The fluorescent material is firmly adsorbed onto the surface of aluminum powder through hydrogen bonds and coordination bonds. Then, a silica layer is prepared by gel-sol method to coat the fluorescent material onto the surface of aluminum powder, thereby forming an aluminum pigment with fluorescent effect and stable performance.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: A method for preparing an aluminum pigment with fluorescent effects includes the following steps: A first coupling agent is grafted onto the surface of aluminum powder to obtain pretreated aluminum powder; Pretreated aluminum powder is immersed in a fluorescent solution to obtain aluminum powder with fluorescent material. Aluminum powder incorporating fluorescent materials is coated with a silica layer to obtain an aluminum pigment with fluorescent properties.

[0006] According to one aspect of the present invention, grafting a first coupling agent onto the surface of aluminum powder comprises: dispersing aluminum powder in a first solvent, heating and stirring until uniform to obtain an aluminum powder suspension, adding the first coupling agent dropwise into the aluminum powder suspension and stirring, followed by post-treatment to obtain pretreated aluminum powder.

[0007] According to one aspect of the present invention, the mass ratio of the aluminum powder, the first solvent, and the first coupling agent is (90-110):(480-520):1. Preferably, the first coupling agent is an aminosilane coupling agent, specifically KH-550 or KH-792. The first solvent is an alcohol solvent, preferably n-propanol.

[0008] According to one aspect of the invention, the first coupling agent is diluted before being added dropwise to the aluminum powder suspension. The dilution process includes adding a second solvent to the first coupling agent. Preferably, the second solvent is n-propanol.

[0009] According to one aspect of the present invention, the step of immersing the pretreated aluminum powder in a fluorescent solution comprises: placing the fluorescent material in a third solvent and stirring until homogeneous to obtain a fluorescent solution; immersing the pretreated aluminum powder in the fluorescent solution and stirring to disperse it to obtain a suspension; and precipitating, separating, washing, and drying the suspension to obtain aluminum powder incorporating the fluorescent material.

[0010] According to one aspect of the invention, the mass ratio of the fluorescent material to the third solvent is (1-2):50. The drying temperature is 58-62°C. Preferably, the third solvent is ethanol.

[0011] According to one aspect of the present invention, the fluorescent material is 8-hydroxyquinoline aluminum.

[0012] According to one aspect of the present invention, the process of coating the surface of aluminum powder incorporating fluorescent material with a silica layer comprises: dispersing the aluminum powder incorporating fluorescent material in a fourth solvent, adjusting the pH to 9-10, adding tetraethoxysilane dropwise and reacting, then adding a second coupling agent dropwise and stirring, followed by separation, washing, and drying to obtain an aluminum pigment with fluorescent effects. The second coupling agent is KH-550 coupling agent. The mass ratio of the aluminum powder incorporating fluorescent material, the fourth solvent, tetraethoxysilane, and the second coupling agent is (90-110):(580-620):(25-35):(1-3). The second coupling agent is KH-550 coupling agent.

[0013] According to one aspect of the invention, the fourth solvent is n-propanol.

[0014] Application of the aforementioned fluorescent aluminum pigment in coatings.

[0015] Advantages of implementing this invention: 1. Fluorescent materials are firmly adsorbed onto the surface of aluminum powder through hydrogen bonds and coordination bonds, so that the aluminum powder and fluorescent materials are tightly combined. The high reflectivity of aluminum powder is used as a "microscopic reflection cavity" to effectively collect and direct the light emitted by the fluorescent material in all directions. This fundamentally solves the light dissipation problem caused by traditional layered structures or simple mixing, and achieves a luminous intensity and a longer afterglow time that are significantly higher than those of existing technologies.

[0016] 2. By surface coating modification, a dense silica protective layer is formed on the surface of the fluorescent material particles. Without compromising the luminescence effect, it protects the aluminum sheet and fluorescent material by isolating them from external temperature and oxidizing gases, thereby increasing the service life of the fluorescent material and significantly improving its stability in harsh environments such as high temperature and high humidity.

[0017] 3. By coating and then water-based, the fluorescent material can be dispersed in a pure water system and can be used in water-based environmentally friendly paints, greatly improving the environmental protection effect. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the appearance of the aluminum pigment with fluorescent effect described in Example 1.

[0020] Figure 2 This is a fluorescence effect diagram of the aluminum pigment in Example 1 excited by a 365nm ultraviolet lamp under dark room conditions. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] A method for preparing an aluminum pigment with fluorescent effects includes the following steps: A first coupling agent is grafted onto the surface of aluminum powder to obtain pretreated aluminum powder; Pretreated aluminum powder is immersed in a fluorescent solution to obtain aluminum powder with fluorescent material. Aluminum powder incorporating fluorescent materials is coated with a silica layer to obtain an aluminum pigment with fluorescent properties.

[0023] In practical applications, grafting the first coupling agent onto the surface of aluminum powder includes: dispersing aluminum powder in a first solvent, heating and stirring until uniform to obtain an aluminum powder suspension, adding the first coupling agent dropwise to the aluminum powder suspension and stirring, followed by post-treatment to obtain pretreated aluminum powder.

[0024] In practical applications, the mass ratio of the aluminum powder, the first solvent, and the first coupling agent is (90-110):(480-520):1. Preferably, the first coupling agent is an aminosilane coupling agent, specifically KH-550 or KH-792. The first solvent is an alcohol solvent, preferably n-propanol.

[0025] In practical applications, the first coupling agent is diluted before being added to the aluminum powder suspension. The dilution process includes adding a second solvent to the first coupling agent. Preferably, the second solvent is n-propanol.

[0026] In practical applications, immersing the pretreated aluminum powder in the fluorescent solution includes: placing the fluorescent material in a third solvent, stirring until homogeneous to obtain a fluorescent solution, immersing the pretreated aluminum powder in the fluorescent solution and stirring to disperse it to obtain a suspension, and precipitating, separating, washing and drying the suspension to obtain aluminum powder incorporating the fluorescent material.

[0027] In practical applications, the mass ratio of the fluorescent material to the third solvent is (1-2):50. The drying temperature is 58-62°C. Preferably, the third solvent is ethanol.

[0028] In practical applications, the fluorescent material is 8-hydroxyquinoline aluminum. 8-hydroxyquinoline aluminum is easy to disperse evenly and can achieve coordination fixation after contact with the surface of pretreated aluminum powder.

[0029] In practical applications, the process of coating the surface of aluminum powder incorporating fluorescent materials with a silica layer includes: dispersing the aluminum powder incorporating fluorescent materials in a fourth solvent, adjusting the pH to 9-10, adding tetraethoxysilane dropwise and reacting at 60-80°C, then adding a second coupling agent dropwise and stirring, followed by separation, washing, and drying to obtain an aluminum pigment with fluorescent effects. The second coupling agent is KH-550. The mass ratio of the aluminum powder incorporating fluorescent materials, the fourth solvent, tetraethoxysilane, and the second coupling agent is (90-110):(580-620):(25-35):(1-3). Preferably, the fourth solvent is n-propanol.

[0030] In practical applications, the pretreated aluminum powder surface incorporates amino activation sites, allowing the fluorescent material to adhere firmly to the aluminum powder surface via coordination sites and hydrogen bonds. The silica layer forms a dense inorganic protective shell, protecting the inner aluminum powder and fluorescent material from physical damage.

[0031] An aluminum pigment with fluorescent properties comprises, from the inside out, an aluminum powder layer, a fluorescent material layer, and a protective layer. The fluorescent material layer is 8-hydroxyquinoline aluminum bonded to the surface of the aluminum powder, and the protective layer is a silica layer coating the outside of the fluorescent material layer. The fluorescent aluminum pigment is prepared by the following method: A first coupling agent is grafted onto the surface of aluminum powder to obtain pretreated aluminum powder; Pretreated aluminum powder was immersed in an 8-hydroxyquinoline aluminum solution to obtain aluminum powder with fluorescent material. Aluminum powder incorporating fluorescent materials is coated with a silica layer to obtain an aluminum pigment with fluorescent properties.

[0032] The aforementioned fluorescent aluminum pigments can be widely used in various coating systems, specifically suitable for coating scenarios that require metallic texture and special visual effects, such as printing inks and decorative metallic paints.

[0033] Example 1 A method for preparing an aluminum pigment with fluorescent effects includes the following steps: S1: Take 100g of aluminum powder with an average particle size of 25μm and a purity >99.5%, add it to 500ml of n-propanol, heat to 50℃, and stir continuously at 300rpm for 1 hour using a magnetic stirrer to obtain a uniformly dispersed aluminum powder suspension. Then take 1g of coupling agent KH-550, add 15ml of n-propanol to dilute the coupling agent KH-550, obtaining a diluted KH-550 solution. Add the diluted KH-550 solution slowly dropwise to the stirred aluminum powder suspension, continuing the dropwise addition for 10 minutes. After the dropwise addition is complete, stir uniformly for 3 hours, then turn off the stirrer, centrifuge and dry the aluminum powder suspension to obtain pretreated aluminum powder.

[0034] S2: Add 9g of 8-hydroxyquinoline aluminum to 300g of ethanol and stir to dissolve to obtain a solution. Then add 95g of the pretreated aluminum powder to the solution and stir thoroughly at 500rpm at 60℃ for 2 hours to obtain a suspension. Let the suspension stand for 3 hours until it separates into layers. Then centrifuge the aluminum powder in the lower layer and dry it in an oven at 60℃ for 30min to obtain aluminum powder with fluorescent material.

[0035] S3: Add 95g of aluminum powder incorporating fluorescent material to 600ml of n-propanol and disperse by stirring at 600rpm for 1 hour at 60℃. Add 50g of purified water and 40g of triethanolamine to adjust the pH to 9. Add 25g of tetraethoxysilane dropwise over 2 hours, and continue the reaction for 4 hours. Then add 1g of coupling agent KH-550 dropwise and continue stirring for another 4 hours. After the reaction is complete and cooled, collect the aluminum powder by centrifugation and dry it in a 60℃ oven for 30 minutes to obtain an aluminum pigment with fluorescent effects. Figure 1 This is a schematic diagram showing the appearance of the fluorescent aluminum pigment prepared in this embodiment. Figure 2 This image shows the fluorescence effect of the aluminum pigment prepared in this embodiment being excited by a 365nm ultraviolet lamp under dark conditions.

[0036] Example 2 A method for preparing an aluminum pigment with fluorescent effects includes the following steps: S1: Take 50g of aluminum powder with an average particle size of 25μm and a purity >99.5%, add it to 500ml of n-propanol, heat to 50℃, and stir continuously at 300 rpm for 1 hour using a magnetic stirrer to obtain a uniformly dispersed aluminum powder suspension. Then take 1g of coupling agent KH-550, add 15ml of n-propanol to dilute the coupling agent KH-550, obtaining a diluted KH-550 solution. Add the diluted KH-550 solution slowly dropwise to the stirred aluminum powder suspension, continuing the dropwise addition for 10 minutes. After the dropwise addition is complete, stir uniformly for 3 hours, then turn off the stirrer, centrifuge and dry the aluminum powder suspension to obtain pretreated aluminum powder.

[0037] S2: Add 6g of 8-hydroxyquinoline aluminum to 300g of ethanol and stir to dissolve, then add 45g of the pretreated aluminum powder to the solution and stir thoroughly at 500rpm at 60℃ for 2 hours to obtain a suspension. Then let the suspension stand for 3 hours until it separates into layers. Centrifuge the lower layer of precipitated aluminum powder and dry it in an oven at 60℃ for 30 minutes to obtain aluminum powder with fluorescent material.

[0038] S3: Add 45g of aluminum powder incorporating fluorescent material to 400ml of n-propanol and disperse by stirring at 600rpm for 1 hour at 60℃. Add 50g of purified water and 40g of triethanolamine to adjust the pH to 9. Add 25g of tetraethoxysilane dropwise over 2 hours, and continue the reaction for 4 hours. Then add 1g of coupling agent KH-550 dropwise and continue stirring for another 4 hours. After the reaction is complete and cooled, collect the aluminum powder by centrifugation and dry it in a 60℃ oven for 30 minutes to obtain an aluminum pigment with fluorescent effects.

[0039] Example 3 S1: Take 150g of aluminum powder with an average particle size of 25μm and a purity >99.5%, add it to 500ml of n-propanol, heat to 50℃, and stir continuously at 300 rpm for 1 hour using a magnetic stirrer to obtain a uniformly dispersed aluminum powder suspension. Then take 1g of coupling agent KH-550, add 15ml of n-propanol to dilute the coupling agent KH-550, obtaining a diluted KH-550 solution. Add the diluted KH-550 solution slowly dropwise to the stirred aluminum powder suspension, continuing the dropwise addition for 10 minutes. After the dropwise addition is complete, stir uniformly for 3 hours, then turn off the stirrer, centrifuge and dry the aluminum powder suspension to obtain pretreated aluminum powder.

[0040] S2: Add 12g of 8-hydroxyquinoline aluminum to 300g of ethanol and stir to dissolve, obtaining a solution. Then add 145g of the pretreated aluminum powder to the solution and stir thoroughly at 500rpm for 2 hours at 60℃ to obtain a suspension. Let the suspension stand for 3 hours until it separates into layers. Centrifuge the lower layer of precipitated aluminum powder and dry it in a 60℃ oven for 30 minutes to obtain aluminum powder bound with fluorescent materials.

[0041] S3: Add 145g of aluminum powder incorporating fluorescent material to 800ml of n-propanol and disperse by stirring at 600rpm for 1 hour at 80℃. Add 50g of purified water and 40g of triethanolamine to adjust the pH to 10. Add 25g of tetraethoxysilane dropwise over 2 hours, and continue the reaction for 4 hours. Then add 1g of coupling agent KH-550 dropwise and continue stirring for another 4 hours. After the reaction is complete and cooled, collect the aluminum powder by centrifugation and dry it in a 60℃ oven for 30 minutes to obtain an aluminum pigment with fluorescent effects.

[0042] Example 4 S1: Take 100g of aluminum powder with an average particle size of 25μm and a purity >99.5%, add it to 500ml of n-propanol, heat to 50℃, and stir continuously at 300 rpm for 1 hour using a magnetic stirrer to obtain a uniformly dispersed aluminum powder suspension. Then take 1g of coupling agent KH-550, add 15ml of n-propanol to dilute the coupling agent KH-550, obtaining a diluted KH-550 solution. Add the diluted KH-550 solution slowly dropwise to the stirred aluminum powder suspension, continuing the dropwise addition for 10 minutes. After the dropwise addition is complete, stir uniformly for 3 hours, then turn off the stirrer, centrifuge and dry the aluminum powder suspension to obtain pretreated aluminum powder.

[0043] S2: Add 12g of 8-hydroxyquinoline aluminum to 300g of ethanol and stir to dissolve, obtaining a solution. Then add 95g of the pretreated aluminum powder to the solution and stir thoroughly at 500rpm for 2 hours at 60℃. Let the suspension stand for 3 hours until it separates into layers. Centrifuge the lower precipitated aluminum powder and dry it in a 60℃ oven for 30 minutes to obtain aluminum powder incorporating fluorescent materials.

[0044] S3: Add 95g of aluminum powder incorporating fluorescent material to 800ml of n-propanol and disperse by stirring at 600rpm for 1 hour at 60℃. Add 50g of purified water and 40g of triethanolamine to adjust the pH to 9. Add 25g of tetraethoxysilane dropwise over 2 hours, and continue the reaction for 4 hours. Then add 1g of coupling agent KH-550 dropwise and continue stirring for another 4 hours. After the reaction is complete and cooled, collect the aluminum powder by centrifugation and dry it in a 60℃ oven for 30 minutes to obtain an aluminum pigment with fluorescent effects.

[0045] Example 5 S1: Take 100g of aluminum powder with an average particle size of 25μm and a purity >99.5%, add it to 500ml of n-propanol, heat to 50℃, and stir continuously at 300 rpm for 1 hour using a magnetic stirrer to obtain a uniformly dispersed aluminum powder suspension. Then take 1g of coupling agent KH-792, add 15ml of n-propanol to dilute the coupling agent KH-792, obtaining a diluted KH-792 solution. Add the diluted KH-792 solution slowly dropwise to the stirred aluminum powder suspension, continuing the dropwise addition for 10 minutes. After the dropwise addition is complete, stir uniformly for 3 hours, then turn off the stirrer, centrifuge and dry the aluminum powder suspension to obtain pretreated aluminum powder.

[0046] S2: Add 9g of 8-hydroxyquinoline aluminum to 300g of ethanol and stir to dissolve to obtain a solution. Then add 95g of the pretreated aluminum powder to the solution and stir thoroughly at 500rpm at 60℃ for 2 hours to obtain a suspension. Let the suspension stand for 3 hours until it separates into layers. Then centrifuge the aluminum powder in the lower layer and dry it in an oven at 60℃ for 30min to obtain aluminum powder with fluorescent material.

[0047] S3: Add 95g of aluminum powder incorporating fluorescent material to 600ml of n-propanol and disperse by stirring at 600rpm for 1 hour at 60℃. Add 50g of purified water and 40g of triethanolamine to adjust the pH to 10. Add 25g of tetraethoxysilane dropwise over 2 hours, and continue the reaction for 4 hours. Then add 1g of coupling agent KH-792 dropwise and continue stirring for another 4 hours. After the reaction is complete and cooled, collect the aluminum powder by centrifugation and dry it in a 60℃ oven for 30 minutes to obtain an aluminum pigment with fluorescent effects.

[0048] Comparative Example 1 The difference from Example 1 is that the step of adding KH-550 in step S1 is omitted; all other steps are the same as in Example 1. S1: Take 100g of aluminum powder with an average particle size of 25μm and a purity of >99.5%, add it to 500ml of n-propanol, heat it to 50℃, and stir it continuously for 1 hour at a speed of 300 rpm using a magnetic stirrer to obtain a uniformly dispersed aluminum powder suspension.

[0049] S2: Add 9g of 8-hydroxyquinoline aluminum to 300g of ethanol and stir to dissolve to obtain a solution. Then add the aluminum powder suspension to the solution and stir thoroughly at 500rpm at 60℃ for 2 hours to obtain a suspension. Let the suspension stand for 3 hours until it separates into layers. Then centrifuge the aluminum powder precipitated in the lower layer and dry it in an oven at 60℃ for 30 minutes to obtain aluminum powder with fluorescent material.

[0050] S3: Add 95g of aluminum powder incorporating fluorescent material to 600ml of n-propanol and disperse by stirring at 600rpm for 1 hour at 60℃. Add 50g of purified water and 40g of triethanolamine to adjust the pH to 9. Add 25g of tetraethoxysilane dropwise over 2 hours, and continue the reaction for 4 hours. Then add 1g of coupling agent KH-550 dropwise and continue stirring for another 4 hours. After the reaction is complete and cooled, collect the aluminum powder by centrifugation and dry it in a 60℃ oven for 30 minutes to obtain an aluminum pigment with fluorescent effects.

[0051] Comparative Example 2 The difference from Example 1 is that S3 is omitted, while the rest is the same as Example 1.

[0052] Comparative Example 3 The difference from Example 1 is that the reaction temperature of S3 is reduced to 50°C, while the rest is the same as in Example 1.

[0053] Performance testing: The fluorescent aluminum pigments prepared in Examples 1, 2, 3, 4, 5, Comparative Examples 1, 2, and 3, as well as aluminum powder with an average particle size of 25 μm and a purity > 99.5% as blank control samples, were subjected to the following performance tests. The specific testing methods for each performance are as follows: Fluorescence performance test: Each sample was evenly spread on white paper or a quartz plate, forming a thin, uniform, non-overlapping, and gapless monolayer. In a dark room, a 365 nm ultraviolet lamp was used to vertically irradiate the sample surface, with the vertical distance between the ultraviolet light source and the sample surface controlled at 10 cm to 15 cm and the irradiation time at 3 to 5 seconds. The observable fluorescence intensity of each sample under ultraviolet excitation was observed and recorded.

[0054] Solvent resistance test: Take 0.02g of each sample and place it in 2 mL of chloroform or dichloromethane. Disperse ultrasonically for 4–6 minutes and observe after standing. If the solution turns yellow or yellow-green, it indicates that the silica coating layer is incomplete and the fluorescent material is not effectively coated. If the solution is clear and transparent, it indicates that the silica coating layer is complete and dense.

[0055] Thermal stability verification: Equal amounts of the test samples were placed in clean crucibles, and the crucibles were placed in muffle furnaces or ovens. The crucibles were heated at 150℃, 200℃, 250℃, and 300℃ for 30 min at each temperature. The test was conducted in parallel using brand new test samples at each temperature point. After heating, the samples were removed and allowed to cool naturally to room temperature. The samples were then excited with a 365nm ultraviolet lamp in a dark room, and the fluorescence intensity of the samples was observed and recorded.

[0056] The performance test results are shown in Table 1 below. Among them, strong fluorescence indicates high fluorescence brightness, uniform luminescence, and clear visibility to the human eye; weak fluorescence indicates low fluorescence brightness, basically uniform luminescence, and identifiable to the human eye; weak fluorescence indicates low fluorescence brightness, uneven luminescence, and barely visible to the human eye; no fluorescence indicates no fluorescence signal and only the original color of the substrate.

[0057] Table 1

[0058] Advantages of implementing this invention: 1. Fluorescent materials are firmly adsorbed onto the surface of aluminum powder through hydrogen bonds and coordination bonds, so that the aluminum powder and fluorescent materials are tightly combined. The high reflectivity of aluminum powder is used as a "microscopic reflection cavity" to effectively collect and direct the light emitted by the fluorescent material in all directions. This fundamentally solves the light dissipation problem caused by traditional layered structures or simple mixing, and achieves a luminous intensity and a longer afterglow time that are significantly higher than those of existing technologies.

[0059] 2. By surface coating modification, a dense silica protective layer is formed on the surface of the fluorescent material particles. Without compromising the luminescence effect, it protects the aluminum sheet and fluorescent material by isolating them from external temperature and oxidizing gases, thereby increasing the service life of the fluorescent material and significantly improving its stability in harsh environments such as high temperature and high humidity.

[0060] 3. By coating and then water-based, the fluorescent material can be dispersed in a pure water system and can be used in water-based environmentally friendly paints, greatly improving the environmental protection effect.

[0061] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing an aluminum pigment with fluorescent effects, characterized in that, Includes the following steps: A first coupling agent is grafted onto the surface of aluminum powder to obtain pretreated aluminum powder; Pretreated aluminum powder is immersed in a fluorescent solution to obtain aluminum powder with fluorescent material. Aluminum powder incorporating fluorescent materials is coated with a silica layer to obtain an aluminum pigment with fluorescent properties.

2. The method for preparing an aluminum pigment with fluorescent effect according to claim 1, characterized in that, The process of grafting a first coupling agent onto the surface of aluminum powder includes: dispersing aluminum powder in a first solvent, heating and stirring to obtain an aluminum powder suspension, adding the first coupling agent dropwise to the aluminum powder suspension and stirring, followed by post-treatment to obtain pretreated aluminum powder.

3. The method for preparing an aluminum pigment with fluorescent effect according to claim 2, characterized in that, The mass ratio of the aluminum powder, the first solvent, and the first coupling agent is (90-110):(480-520):

1.

4. The method for preparing an aluminum pigment with fluorescent effect according to claim 2, characterized in that, The first coupling agent is an aminosilane coupling agent.

5. The method for preparing an aluminum pigment with fluorescent effect according to claim 2, characterized in that, The first solvent is an alcohol solvent.

6. The method for preparing an aluminum pigment with fluorescent effect according to claim 1, characterized in that, The step of immersing the pretreated aluminum powder in the fluorescent solution includes: placing the fluorescent material in a third solvent, stirring until uniform to obtain a fluorescent solution, immersing the pretreated aluminum powder in the fluorescent solution and stirring to disperse it to obtain a suspension, and precipitating, separating, washing and drying the suspension to obtain aluminum powder bound with the fluorescent material.

7. The method for preparing an aluminum pigment with fluorescent effect according to claim 6, characterized in that, The mass ratio of the fluorescent material to the third solvent is (1-2):

50.

8. The method for preparing an aluminum pigment with fluorescent effect according to claim 6, characterized in that, The fluorescent material is 8-hydroxyquinoline aluminum.

9. The method for preparing an aluminum pigment with fluorescent effect according to claim 1, characterized in that, The process of coating the surface of aluminum powder with fluorescent material with a silica layer includes: dispersing the aluminum powder with fluorescent material in a fourth solvent, adjusting the pH to 9-10, adding tetraethoxysilane dropwise and reacting, then adding a second coupling agent dropwise and stirring, followed by separation, washing, and drying to obtain an aluminum pigment with fluorescent effect.

10. A method for preparing an aluminum pigment with fluorescent effect according to claim 9, characterized in that, The mass ratio of the aluminum powder containing the fluorescent material, the fourth solvent, the tetraethoxysilane, and the second coupling agent is (90-110): (580-620): (25-35): (1-3).

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