Special paper containing CaAl2O4: Pr < 3 + >, Nd < 3 + > luminescent powder and preparation method thereof

Abstract

The invention belongs to the crossing field of functional materials and anti-counterfeiting technologies, and discloses specialty paper containing CaAl2O4: Pr < + >, Nd < + > luminescent materials and a preparation method thereof, and the preparation method comprises the following preparation steps: firstly, grinding calcium carbonate, aluminum oxide and boric acid in a mortar to realize preliminary uniform mixing, then adding praseodymium neodymium oxide, and continuing grinding; after the raw materials are fully mixed, the sample powder is subjected to tabletting treatment, tablets are sequentially put into small crucibles, the adjacent tablets are spaced, and then the small crucibles are put into a large crucible containing graphite powder; putting the large crucible into a high-temperature furnace, slowly heating to a sintering temperature at a certain heating rate, preserving heat, naturally cooling to room temperature, and taking out a sample in the crucible; and finally, fully grinding the sample by using a mortar, and controlling the grinding temperature to obtain CaAl2O4: Pr < + >, Nd < + > luminescent powder. And adding the prepared CaAl2O4: Pr < + >, Nd < + > luminescent powder into the pulped paper pulp solution, and carrying out papermaking on the mixed paper pulp solution to obtain the specialty paper containing the CaAl2O4: Pr < + >, Nd < + > luminescent powder. A high-temperature solid-phase method is adopted, the process is mature and stable, operation is easy and convenient, complex equipment is not needed, and the method is suitable for industrial large-scale production. The compounding process of the luminescent material and paper pulp is simple and easy to popularize and apply in the papermaking industry.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of functional materials and anti-counterfeiting technology, specifically involving a technology for preparing anti-counterfeiting paper based on rare earth ion co-doped calcium aluminum oxide luminescent material, which is suitable for high-security printed materials such as banknotes, tickets, and certificates. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Specialty paper, possessing unique functions distinct from ordinary paper, is experiencing a continuously rising market demand in areas such as anti-counterfeiting, labeling, and high-end consumer goods. Among these, luminescent specialty paper, with its luminescent properties under ultraviolet excitation and in dark environments, has become a core carrier for anti-counterfeiting and nighttime labeling technologies. In the field of inorganic luminescent material synthesis, the high-temperature solid-state method is a classic and mature technical route, boasting significant advantages such as simple operation, low equipment requirements, and ease of large-scale production, making it widely used in research and industry for luminescent material preparation. However, existing CaAl2O4-based Pr³... + 、Nd³ + The composite effect of the luminescent powder with special paper is poor, making it difficult to obtain a better luminescent effect.

[0004] Therefore, it is urgent to prepare CaAl2O4:Pr³ fluorescein with superior luminescence performance. + ,Nd³ + Specialty paper with luminescent powder. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method containing CaAl2O4:Pr³ + ,Nd³ + Specialty paper containing luminescent powder and its preparation method. This invention develops a CaAl2O4:Pr³ powder prepared by a high-temperature solid-state method. + ,Nd³ + Luminescent powders can be combined with pulp to prepare specialty papers, which has significant industrial value.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a solution containing CaAl2O4:Pr³ + ,Nd³ + The preparation method of specialty paper with luminescent powder includes: Calcium salt, aluminum salt, and boric acid were mixed evenly, then praseodymium salt and neodymium salt were added and mixed evenly. The mixture was then prepared, sintered, and CaAl₂O₄:Pr³ was obtained. + ,Nd³+ Luminescent powder; Add the CaAl2O4:Pr³ to the pulp solution after beating. + ,Nd³ + Luminescent powder, mixed evenly, is then subjected to papermaking to obtain a product containing CaAl2O4:Pr³. + ,Nd³ + Specialty paper with luminescent powder.

[0007] This invention has found that the integrity and order of the crystal structure affect the CaAl2O4:Pr³ + ,Nd³ + To investigate the luminescent effect of luminescent powder combined with special paper, this invention studied flux, sintering atmosphere, and sintering temperature to obtain CaAl2O4:Pr³ with better crystal structure integrity and order. + ,Nd³ + Luminescent powder; simultaneously, this invention also relates to CaAl2O4:Pr³ + ,Nd³ + The process of laminating luminescent powder with paper was studied, which significantly improved the content of CaAl2O4:Pr³. + ,Nd³ + The luminescent effect of special paper with luminescent powder.

[0008] A second aspect of the present invention provides a CaAl2O4:Pr³ compound prepared by the above method. + ,Nd³ + Specialty paper with luminescent powder.

[0009] A third aspect of the present invention provides the above-mentioned CaAl2O4:Pr³ + ,Nd³ + Applications of luminescent powder-coated specialty paper in anti-counterfeiting, labeling, and high-end consumer sectors.

[0010] Beneficial effects of the present invention (1) The present invention adopts the high temperature solid phase method, which is mature and stable, easy to operate, and does not require complex equipment, making it suitable for large-scale industrial production.

[0011] (2) The composite process of the luminescent material and pulp of the present invention is simple and easy to promote and apply in the papermaking industry.

[0012] (3) This invention investigated flux, sintering atmosphere and sintering temperature, and obtained CaAl2O4:Pr³ with better crystal structure integrity and order. + ,Nd³ + Luminescent powder; simultaneously, this invention also relates to CaAl2O4:Pr³ + ,Nd³ +The process of laminating luminescent powder with paper was studied, which significantly improved the content of CaAl2O4:Pr³. + ,Nd³ + The luminescent effect of special paper with luminescent powder. Attached Figure Description

[0013] The accompanying drawings, which form part of this specification, are intended to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are for illustrative purposes only and do not constitute any undue limitation of the invention.

[0014] Figure 1 The CaAl2O4:Pr³ obtained in Example 1 + ,Nd³ + XRD pattern of luminescent material; Figure 2 The CaAl2O4:Pr³ obtained in Example 2 + ,Nd³ + XRD pattern of luminescent material; Figure 3 The CaAl2O4:Pr³ obtained in Example 3 + ,Nd³ + XRD pattern of luminescent material. Detailed Implementation

[0015] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0016] This invention provides a CaAl2O4:Pr³ + ,Nd³ + The preparation method of specialty paper with luminescent powder includes: Calcium salt, aluminum salt, and boric acid were mixed evenly, then praseodymium salt and neodymium salt were added and mixed evenly. The mixture was then prepared, sintered, and CaAl₂O₄:Pr³ was obtained. + ,Nd³ + Luminescent powder; Add the CaAl2O4:Pr³ to the pulp solution after beating. + ,Nd³ + Luminescent powder, mixed evenly, is then subjected to papermaking to obtain a product containing CaAl2O4:Pr³. + ,Nd³ + Specialty paper with luminescent powder.

[0017] The type of calcium salt affects the crystal structure and luminescence performance of luminescent materials. Therefore, this invention studies the types of calcium salts, preferably calcium carbonate, to obtain better luminescence performance.

[0018] The type of aluminum salt affects the crystal structure and luminescence performance of luminescent materials. Therefore, this invention studies the types of aluminum salts. Preferably, the aluminum salt is aluminum oxide to obtain better luminescence performance.

[0019] The mixing method, purity, and particle size of raw materials affect the performance of luminescent materials. Therefore, this invention studies the mixing method, purity, and particle size of raw materials. Preferably, calcium carbonate, alumina, and boric acid are ground in a mortar to achieve preliminary uniform mixing. The purity of calcium carbonate is 99.95-99.99%, the purity of alumina is 95.0-99.0%, and the purity of boric acid is 95.0-99.0%. After grinding, the particle size of the mixture of calcium carbonate, alumina, and boric acid is 100-300 mesh to obtain better luminescent performance.

[0020] The type and purity of praseodymium and neodymium salts affect the crystal structure and luminescence performance of luminescent materials. Therefore, this invention studies the type and purity of aluminum salts. Preferably, both the praseodymium and neodymium salts are praseodymium-neodymium oxide with a purity of 99.990~99.999% to obtain better luminescence performance.

[0021] The mixing method and final particle size of doping elements affect the crystal structure and luminescence performance of luminescent materials. Therefore, this invention studies the doping method of praseodymium oxide and the particle size after doping. Preferably, praseodymium oxide is then added and further grinding is performed. After grinding, the particle size of the mixture of praseodymium oxide, calcium carbonate, aluminum oxide, and boric acid is 100-300 mesh to obtain better luminescence performance.

[0022] In order to obtain CaAl2O4-based luminescent materials with better performance, the present invention studied the mass ratio of calcium carbonate to aluminum oxide. Preferably, the mass ratio of calcium carbonate to aluminum oxide is 1:1.00~1.05 to obtain better luminescent performance.

[0023] In order to reduce the sintering temperature, promote crystallization, and optimize the particle size distribution, this invention uses boric acid as a flux and studies its addition amount. Preferably, the mass ratio of calcium carbonate to boric acid is 30~35:1, so as to better reduce the sintering temperature, promote crystallization, and optimize the particle size distribution.

[0024] By doping with praseodymium and neodymium, the luminescence performance of materials can be effectively improved. Therefore, this invention studies the doping amount of praseodymium and neodymium. Preferably, the mass ratio of praseodymium oxide to a mixture of calcium carbonate, aluminum oxide, and boric acid is 1:15~50 to effectively improve the luminescence performance.

[0025] Preferably, after the raw materials are fully mixed, the sample powder is compressed into tablets. The pressure range is 20–50 MPa, the holding time is 1–5 min, the tablet diameter is 10–40 mm, and the thickness is 1–5 mm. The tableting process, through precise pressure control, uniformly compresses the sample powder into a tablet-like structure. This molding method reduces porosity between particles, enhances the material's density, and thus improves luminescence efficiency.

[0026] Preferably, the pressing tablets are placed sequentially into the small crucible with adjacent pressing tablets spaced apart, and the spacer material used is graphite paper, so as to take advantage of its high thermal conductivity and chemical stability to optimize the heat conduction of the material.

[0027] Preferably, the small crucible is then placed in a large crucible containing graphite powder with a purity of 95.0-99.0%, in order to utilize its high temperature resistance, high thermal conductivity and chemical stability to improve the high-temperature sintering effect.

[0028] Preferably, the small crucible is then placed in a large crucible containing graphite powder with a particle size of 100-200 mesh, so as to improve its thermal conductivity by adjusting the particle size.

[0029] During high-temperature sintering, the ratio of graphite powder to calcium carbonate affects the sintering effect and product quality. Therefore, this invention studies the mass ratio of graphite powder to calcium carbonate. Preferably, the small crucible is placed in a large crucible containing graphite powder, and the mass ratio of graphite powder to calcium carbonate is 1.5~2.5:1 to obtain a better sintering effect.

[0030] Sintering temperature affects the integrity and order of the crystal structure of luminescent materials. Therefore, this invention studies the sintering temperature. Preferably, the sintering temperature is 1200~1400℃ to better improve the integrity and order of the crystal structure.

[0031] The heat preservation time affects the crystal structure and luminescence performance of the luminescent material. Therefore, this invention studies the heat preservation temperature. Preferably, the heat preservation time is 5.5~7.5h to improve the luminescence performance.

[0032] When the heating rate is too fast, the diffusion and bonding time of the particles inside the material is insufficient, which may lead to a decrease in relative density. Therefore, the present invention has studied the heating rate. Preferably, the large crucible is then placed in a high-temperature furnace and slowly heated to the sintering temperature at a certain heating rate and held at that temperature. The heating rate is 5~20℃ / min to obtain a better sintering effect.

[0033] Research has found that: in order to make CaAl2O4:Pr³ + ,Nd³ +Specialty papers containing luminescent powder exhibit superior luminescent properties, requiring careful control of the CaAl2O4:Pr³ ratio. + ,Nd³ + The particle size of the luminescent powder is within a specific range; therefore, in some embodiments, CaAl2O4:Pr³ + ,Nd³ + The luminescent powder has a particle size of 200-300 mesh to obtain the desired luminescent properties.

[0034] High-temperature grinding may cause lattice distortion in the material, affecting luminescence efficiency. Therefore, this invention investigated the grinding temperature. Preferably, the sample is thoroughly ground in a mortar and pestle at the end, and the grinding temperature is controlled to obtain CaAl2O4:Pr³. + ,Nd³ + The luminescent powder is ground at a temperature of 20~30℃ to obtain a better luminescent effect.

[0035] Preferably, the CaAl2O4:Pr³ + ,Nd³ + The mass ratio of luminescent powder to oven-dried wood pulp is 1:20~50, so that CaAl2O4:Pr³ + ,Nd³ + The luminescent powder is mixed evenly with oven-dried wood pulp to improve the luminescence effect.

[0036] To make CaAl2O4:Pr³ + ,Nd³ + Specialty paper with luminescent powder has superior luminescent properties, and it is necessary to control the pulp beating degree within a specific range. Therefore, in some embodiments, the pulp beating degree is 30~45°SR to obtain the desired luminescent effect.

[0037] Preferably, the mass ratio of oven-dry fiber to water in the mixed pulp solution is 1:80~120 to ensure uniform mixing of the pulp.

[0038] Preferably, CaAl2O4:Pr³ + ,Nd³ + The order of adding luminescent powder and pulp is CaAl2O4:Pr³ + ,Nd³ + The luminescent powder is added to the pulp to ensure uniform mixing and facilitate operation.

[0039] Preferably, the pulp includes mechanical pulp, chemical pulp, and chemimechanical pulp, wherein the mechanical pulp is mixed with CaAl2O4:Pr³ + ,Nd³ + The composite effect of luminescent powder is optimal.

[0040] More specifically, including: First, calcium carbonate, aluminum oxide, and boric acid were ground in a mortar to achieve preliminary uniform mixing. Then, praseodymium oxide was added and grinding continued. After the raw materials were fully mixed, the sample powder was pressed into tablets. The tablets were placed sequentially into small crucibles, spaced apart, and then placed in a large crucible containing graphite powder. Next, the large crucible was placed in a high-temperature furnace and slowly heated to the sintering temperature at a controlled rate, then held at that temperature. After naturally cooling to room temperature, the sample was removed from the crucible. Finally, the sample was thoroughly ground in a mortar, controlling the grinding temperature, to obtain CaAl₂O₄:Pr³. + ,Nd³ + Luminescent powder. The CaAl2O4:Pr³ powder prepared above was added to the pulp solution after beating. + ,Nd³ + Luminescent powder, when mixed with pulp solution, is used to produce papermaking material containing CaAl2O4:Pr³. + ,Nd³ + Specialty paper with luminescent powder.

[0041] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0042] In the following embodiments, the method for preparing mechanical pulp includes: (1) The eucalyptus chips were screened to a size of 10-20mm × 2-5mm, washed to remove impurities, and then pre-steamed at 90℃ for 15min to soften. For the bio-enzyme treatment, xylanase was used at a dosage of 50-100 IU / g of oven-dried wood chips, with a solid-liquid ratio of 1:8, pH 4.5-5.5, and temperature of 45℃. The mixture was stirred at a constant temperature for 60min. After enzymatic hydrolysis, the residue was removed by filtration and washing.

[0043] (2) The grinding process uses a two-stage disc mill: the first stage is high-consistency grinding with a concentration of 30% and a disc gap of 0.10-0.15mm; the second stage is low-consistency fine grinding with a concentration of 15% and a gap of 0.03-0.05mm.

[0044] Methods for preparing chemical pulp include: (1) Eucalyptus chips are screened to a size of 10-20mm×2-5mm, washed to remove impurities and dust, and then directly enter the chemical cooking process. The sulfate cooking method is adopted: 20% alkali (calculated as NaOH), 28% sulfidation, 1:4-1:5 liquor ratio, heated to 165℃, held for 120min, and cooked at a pressure of 0.7MPa.

[0045] (2) After cooking, the black liquor is removed by multiple washings in a vacuum washing machine. The coarse fiber bundles and impurities are removed by a pressure screen (screen gap 0.15mm). After bleaching, the final pulp has a whiteness of 75% ISO.

[0046] The chemimechanical pulp was prepared according to the method described in the paper "Study on Process Conditions of Chemimechanical Pulp Pretreatment with Rice Straw Enzyme - Zhang Zhili".

[0047] Example 1 First, weigh out calcium carbonate (99.95% purity), alumina (95.0% purity), and boric acid (95.0% purity), with a mass ratio of calcium carbonate to alumina of 1:1.00 and a mass ratio of calcium carbonate to boric acid of 30:1. Grind these three materials together in a mortar until the particle size reaches 100 mesh, achieving initial homogeneity. Then, add praseodymium oxide (PrNd)₂O₆ (99.990% purity), with a mass ratio of praseodymium oxide to the aforementioned calcium carbonate, alumina, and boric acid mixture of 1:15. Continue grinding until the particle size of the mixture reaches 100 mesh, ensuring thorough mixing. After mixing, compress the sample powder into tablets at a pressure of 20 MPa for 1 minute, ultimately obtaining tablets with a diameter of 10 mm and a thickness of 1 mm. The compressed tablets were placed sequentially into small crucibles, separated by graphite paper. These small crucibles were then placed into a larger crucible containing graphite powder (95.0% purity, 100 mesh particle size, and a graphite powder to calcium carbonate mass ratio of 1.5:1). The larger crucible containing the tablets and graphite powder was placed in a high-temperature furnace and slowly heated to 1250℃ at a rate of 5℃ / min, holding at this temperature for 5.5 hours. After the furnace cooled naturally to room temperature, the sample was removed from the crucible and ground in a mortar at a controlled temperature of 20℃ until the particle size reached 200 mesh, yielding CaAl₂O₄:Pr³. + ,Nd³ + Luminescent powder. like Figure 1 As shown, the positions of the diffraction peaks in this spectrum match the characteristic peaks of the standard card in PDF#53-0191, indicating that the product is the target CaAl2O4-based phase. However, the diffraction peak intensities are weak, and some peaks exhibit broadening, reflecting that the crystal nucleation and growth process was insufficient during sintering at 1250℃, resulting in low crystallinity, small grain size, and insufficient ordered arrangement of the crystals, possibly indicating the presence of certain amorphous components or structural defects.

[0048] Finally, mechanical pulp was selected as the raw material pulp, and the pulp was beating was performed to control the freeness at 30°SR. The prepared CaAl2O4:Pr³ was then added to the beating pulp. + ,Nd³ + Luminescent powder, wherein CaAl2O4:Pr³ + ,Nd³ +The mass ratio of luminescent powder to oven-dry pulp is 1:20. The mixed pulp solution is adjusted to achieve a mass ratio of oven-dry fiber to water of 1:80. The pulp solution is then stirred to ensure uniform dispersion of the luminescent powder. Finally, the mixed pulp solution is formed on a paper machine, and after dehydration, pressing, and drying, a CaAl₂O₄:Pr³ content is obtained. + ,Nd³ + Special paper for luminescent materials, basis weight 200g / m³ 2 .

[0049] Test results show that when the excitation wavelength is 303 nm, the emission wavelength range is 400~600 nm. The afterglow time is 5 μs.

[0050] Example 2 First, weigh out calcium carbonate (99.96% purity), alumina (97.0% purity), and boric acid (97.0% purity). The mass ratio of calcium carbonate to alumina is 1:1.02, and the mass ratio of calcium carbonate to boric acid is 32:1. Grind the calcium carbonate, alumina, and boric acid in an agate mortar until the particle size is 200 mesh. After initial mixing, add praseodymium oxide (PrNd)₂O₆ (99.995% purity) at a mass ratio of praseodymium oxide to the mixture (1:30). Continue grinding until the particle size of the mixture is 200 mesh. Compress the powder into tablets at a pressure of 40 MPa for 3 minutes to produce tablets with a diameter of 25 mm and a thickness of 3 mm. The tablets were placed in small crucibles spaced apart by graphite paper. These small crucibles were then placed inside a larger crucible containing graphite powder (97.0% purity, 150 mesh particle size), with a graphite powder to calcium carbonate mass ratio of 2.0:1. The larger crucible was placed in a high-temperature furnace and heated to 1300℃ at a rate of 12℃ / min, holding at that temperature for 6.5 hours. After cooling to room temperature, the sample was removed and ground in an agate mortar at 25℃ until the particle size reached 300 mesh, yielding CaAl₂O₄:Pr³. + ,Nd³ + Luminescent powder.

[0051] like Figure 2 As shown in the diagram, the diffraction peak intensity is significantly enhanced, and the peak shape is also sharper. This indicates that when the sintering temperature is increased to 1300℃, the atomic diffusion ability is improved, the thermodynamic driving force for crystal growth is increased, resulting in improved crystallinity, further grain growth, and significant improvement in both phase purity and crystal order.

[0052] Chemical pulp was selected for beating, with the freeness controlled at 38°SR. The aforementioned luminescent powder was added to the beated chemical pulp at a mass ratio of luminescent powder to oven-dry chemical pulp of 1:30. The mass ratio of oven-dry fiber to water in the mixed pulp solution was adjusted to 1:100. After thorough stirring to ensure uniform dispersion of the luminescent powder, the pulp solution was processed on papermaking equipment, undergoing dewatering, pressing, and drying processes to obtain a product containing CaAl2O4:Pr³. + ,Nd³ + Special paper for luminescent materials, basis weight 200g / m³ 2 .

[0053] Test results show that when the excitation wavelength is 303 nm, the emission wavelength range is 600~800 nm. The afterglow time is 8 μs.

[0054] Example 3 Weigh out calcium carbonate (99.97% purity), alumina (99.0% purity), and boric acid (99.0% purity), with a calcium carbonate to alumina mass ratio of 1:1.04 and a calcium carbonate to boric acid mass ratio of 34:1. Grind the three components in an agate mortar until the particle size is 300 mesh. After initial mixing, add praseodymium oxide (PrNd)₂O₆ (99.998% purity), with a praseodymium oxide to neodymium oxide mass ratio of 1:40. Continue grinding until the particle size of the mixture is 300 mesh. Compress the mixed powder into tablets at a pressure of 20 MPa for 5 minutes to obtain tablets with a diameter of 40 mm and a thickness of 5 mm. Place the tablets in small crucibles with spacing using graphite paper. Then, place the small crucibles in a large crucible containing graphite powder (99.0% purity, 200 mesh particle size), with a graphite powder to calcium carbonate mass ratio of 2.5:1. The large crucible was placed in a high-temperature furnace and heated to 1350℃ at a heating rate of 18℃ / min, and held at that temperature for 7.0 h. After cooling to room temperature, the sample was removed and ground in an agate mortar at 28℃ to a particle size of 300 mesh, yielding CaAl2O4:Pr³ + ,Nd³ + Luminescent powder.

[0055] like Figure 3 As shown, the diffraction peaks in this spectrum have the highest intensity and the sharpest, clearest peak shapes. This indicates that 1350℃ is the optimal sintering temperature for crystal growth in this system: at this temperature, crystal growth is most complete, crystallinity reaches a high level, grain size is larger, the integrity and order of the crystal structure are optimal, and the crystal quality of the target phase is best.

[0056] Finally, chemimechanical pulp was selected as the pulp raw material and beating was performed, controlling the freeness to be 45°SR. The luminescent powder prepared above was added to the beated chemimechanical pulp, with a mass ratio of luminescent powder to oven-dry chemimechanical pulp of 1:40. The mass ratio of oven-dry fiber to water in the mixed pulp solution was adjusted to 1:110. After thorough mixing, the pulp solution was fed into a paper machine for papermaking. Subsequent dewatering, pressing, and drying processes yielded a paper containing CaAl2O4:Pr³. + ,Nd³ + Special paper for luminescent materials, basis weight 200g / m³ 2 .

[0057] Test results show that when the excitation wavelength is 303 nm, the emission wavelength range is 500~700 nm. The afterglow time is 8 μs.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A compound containing CaAl2O4:Pr³ + ,Nd³ + A method for preparing specialty paper with luminescent powder, characterized in that, include: Calcium salt, aluminum salt, and boric acid were mixed evenly, then praseodymium salt and neodymium salt were added and mixed evenly. The mixture was then prepared, sintered, and CaAl₂O₄:Pr³ was obtained. + ,Nd³ + Luminescent powder; Add the CaAl2O4:Pr³ to the pulp solution after beating. + ,Nd³ + Luminescent powder, mixed evenly, is then subjected to papermaking to obtain a product containing CaAl2O4:Pr³. + ,Nd³ + Specialty paper with luminescent powder.

2. The CaAl2O4:Pr³ compound as described in claim 1 + ,Nd³ + A method for preparing specialty paper with luminescent powder, characterized in that, The calcium salt is calcium carbonate; Alternatively, the aluminum salt is aluminum oxide; Alternatively, both the praseodymium salt and the neodymium salt are praseodymium-neodymium oxide.

3. The CaAl2O4:Pr³ compound as described in claim 1 + ,Nd³ + A method for preparing specialty paper with luminescent powder, characterized in that, The mass ratio of calcium carbonate to aluminum oxide is 1:1.00~1.05; Alternatively, the mass ratio of calcium carbonate to boric acid is 30~35:1; Alternatively, the mass ratio of praseodymium oxide to a mixture of calcium carbonate, aluminum oxide, and boric acid is 1:15~50.

4. The CaAl2O4:Pr³ compound as described in claim 1 + ,Nd³ + A method for preparing specialty paper with luminescent powder, characterized in that, The sintering temperature is 1200~1400℃.

5. The CaAl2O4:Pr³ compound as described in claim 1 + ,Nd³ + A method for preparing specialty paper with luminescent powder, characterized in that, The heat preservation time is 5.5~7.5 hours.

6. The CaAl2O4:Pr³ compound as described in claim 1 + ,Nd³ + A method for preparing specialty paper with luminescent powder, characterized in that, CaAl2O4:Pr³ + ,Nd³ + The particle size of the luminescent powder is 200~300 mesh.

7. The CaAl2O4:Pr³ compound as described in claim 1 + ,Nd³ + A method for preparing specialty paper with luminescent powder, characterized in that, The CaAl2O4:Pr³ + ,Nd³ + The mass ratio of luminescent powder to oven-dried wood pulp is 1:20~50.

8. The CaAl2O4:Pr³ compound as described in claim 1 + ,Nd³ + A method for preparing specialty paper with luminescent powder, characterized in that, The pulp freeness is 30~45°SR; Alternatively, the mass ratio of oven-dry fibers to water in the mixed pulp solution is 1:80~120.

9. The CaAl2O4:Pr³ compound prepared by the method according to any one of claims 1-8 + ,Nd³ + Specialty paper with luminescent powder.

10. The CaAl2O4:Pr³ compound as described in claim 9 + ,Nd³ + Applications of luminescent powder-coated specialty paper in anti-counterfeiting, labeling, and high-end consumer sectors.

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