An ultra-long afterglow zinc sulfide fluorescent anti-counterfeiting material with simultaneously adjustable fluorescence and afterglow and its application

Abstract

The present invention provides a long afterglow zinc sulfide fluorescent anti-counterfeiting material with simultaneously adjustable fluorescence and afterglow and its application. The fluorescent anti-counterfeiting material contains ZnS: a KA, b CaB2, y Mn 2+ , z R n+ , where A is selected from at least one of Cl, Br, and I, B is selected from at least one of Cl, Br, and I, and R n+ is selected from at least one of Cu 2+ , Ag + , Er 3+ , Sm 3+ , Tm 3+ , Tb 3+ . Among them, 0 ≤ a ≤ 0.1, 0 ≤ b ≤ 0.1, 0 < y ≤ 0.004, 0 < z ≤ 0.001, and a and b are not both 0 at the same time. The fluorescent anti-counterfeiting material prepared by the present invention has the characteristics of variable fluorescence, variable afterglow, and extremely long afterglow delay. Under different ultraviolet light excitations (between 254 - 365 nm), it exhibits fluorescence of different colors (one or more of blue light - orange light), and after the excitation stops, it exhibits afterglow of different colors (one or more of green light - orange light). The fluorescence color of the same phosphor is different from the afterglow color, and the afterglow delay > 5 s, which can be applied to industrial anti-counterfeiting applications.

Description

Technical Field

[0001] The present invention relates to the technical field of inorganic materials, and particularly relates to an ultra-long afterglow zinc sulfide fluorescent anti-counterfeiting material with adjustable fluorescence and afterglow simultaneously and its application. Background Art

[0002] Vigorously developing anti-counterfeiting technologies has become an important measure to ensure national public security, economic order, and the rights and interests of producers and consumers from the source.

[0003] Compared with other anti-counterfeiting technologies (such as laser holography, two-dimensional codes, etc.), the ink anti-counterfeiting technology has the advantages of being easy to implement, intuitively recognizable, having a significant anti-counterfeiting effect, a wide range of applications, and a low cost of technology iteration. Therefore, it has become the dominant technology in the anti-counterfeiting industry. The fluorescent materials added in the fluorescent anti-counterfeiting ink are usually invisible (invisible) or present a certain color under natural light, but will emit different fluorescence under specific excitation sources (such as light, deformation, thermal change, magnetic field), and the color, brightness, and duration of the fluorescence can be designed according to needs, which can endow the ink with diverse anti-counterfeiting effects. Currently, the commercially available fluorescent anti-counterfeiting inks mainly show a fixed color emitted under a fixed excitation, with low anti-counterfeiting performance and being easily forged. Therefore, developing dynamic fluorescent anti-counterfeiting materials with multi-dimensional responses can greatly promote the development of the anti-counterfeiting industry.

[0004] Zinc sulfide matrix doped with rare earth ions or transition metal ions belongs to the category of inorganic materials, and has the advantages of low biological toxicity, rich emission bands, good stability, cheap and easily available materials, and being easy to produce on a large scale. However, most of the reported zinc sulfide luminescent materials are single-mode single-color luminescence or multi-mode single-color luminescence, such as doping with additives (NaCl, NaBr, etc.) or Ag + to achieve blue light emission after doping; doping with Mn 2+ to achieve yellow light emission, doping with Cu 2+ to achieve green light emission and accompanied by green afterglow. In addition, there is also a reported case of achieving multi-mode multi-color luminescence with simultaneous wavelength and time responses through the doping of additives and Mn 2+ However, its afterglow color is single, and the afterglow time is very short (<5 s), with poor resolution and being difficult to promote and apply. Therefore, it is urgent to develop a new type of anti-counterfeiting material with variable fluorescence, variable afterglow, and a long afterglow duration. Summary of the Invention

[0005] The purpose of the present invention is to overcome the drawbacks and deficiencies existing in the prior art, and to provide an ultra-long afterglow zinc sulfide fluorescent anti-counterfeiting material with adjustable fluorescence and afterglow simultaneously and its application.

[0006] The technical solutions adopted by the present invention are as follows:

[0007] The first aspect of the present invention provides a long afterglow zinc sulfide fluorescent anti-counterfeiting material with simultaneously adjustable fluorescence and afterglow. The fluorescent anti-counterfeiting material contains ZnS: a KA, b CaB2, y Mn 2+ , z R n+ ,

[0008] wherein, A is selected from at least one of Cl, Br, and I, B is selected from at least one of Cl, Br, and I, and R n+ is selected from at least one of Cu 2+ , Ag + , Er 3+ , Sm 3+ , Tm 3+ , Tb 3+ . 0 ≤ a ≤ 0.1, 0 ≤ b ≤ 0.1, 0 < y ≤ 0.004, 0 < z ≤ 0.001, and a and b are not both 0.

[0009] Preferably, 0 < a ≤ 0.1, 0 < b ≤ 0.1.

[0010] Preferably, its preparation method includes the following steps:

[0011] S1. Mix the KA solution, CaB2 solution, ZnS, and Mn salt in proportion and dry them at 60 - 100 °C. After drying, add the corresponding oxide and / or carbonate of R n+ and grind them evenly to obtain the precursor powder;

[0012] S2. Place the precursor powder in a box furnace, heat it up to 750 - 1100 °C together and calcine for 2 - 4 h, and then grind it evenly after cooling to room temperature with the furnace.

[0013] Preferably, in step S2, the heating rate is 2 - 12 °C / min.

[0014] Preferably, in step S2, heat up, calcine, and cool in a CO atmosphere.

[0015] Preferably, the CO atmosphere is provided by carbon powder.

[0016] The second aspect of the present invention provides the application of the above-mentioned long afterglow zinc sulfide fluorescent anti-counterfeiting material with simultaneously adjustable fluorescence and afterglow in the preparation of anti-counterfeiting products.

[0017] The beneficial effects of the present invention are as follows: The ZnS prepared by the present invention: x MX, y Mn 2+ / z Rn+ Zinc sulfide fluorescent anti-counterfeiting materials have the characteristics of variable fluorescence, variable afterglow, and extremely long afterglow delay. Under different ultraviolet light excitations (between 254 - 365 nm), they exhibit fluorescence of different colors (one or more of blue light - orange light) and afterglow of different colors (one or more of green light - orange light) after the excitation stops. The fluorescence color of the same phosphor is different from the afterglow color, and the afterglow delay > 5 s, which can be applied to industrial anti-counterfeiting applications. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, obtaining other drawings based on these drawings still belongs to the scope of the present invention.

[0019] Figure 1 (a) Fluorescence spectrum diagram, (b) Afterglow spectrum diagram, (c) CIE coordinate diagram, (d) Afterglow decay spectrum diagram of the phosphor obtained in Example 1;

[0020] Figure 2 (a) Fluorescence spectrum diagram and afterglow spectrum diagram, (b) Afterglow decay spectrum diagram, (c) CIE coordinate diagram of the phosphor obtained in Example 2;

[0021] Figure 3 (a) Fluorescence spectrum diagram and afterglow spectrum diagram, (b) Afterglow decay spectrum diagram, (c) CIE coordinate diagram of the phosphor obtained in Example 3;

[0022] Figure 4 (a) Fluorescence spectrum diagram and afterglow spectrum diagram, (b) Afterglow decay spectrum diagram, (c) CIE coordinate diagram of the phosphor obtained in Example 4;

[0023] Figure 5 (a) Fluorescence spectrum diagram, (b) Phosphorescence spectrum diagram, (c) Afterglow decay spectrum diagram of the phosphor obtained in Example 5;

[0024] Figure 6 (a) Fluorescence spectrum diagram, (b) Afterglow decay spectrum diagram of the phosphor obtained in Example 6;

[0025] Figure 7 (a) Phosphorescence spectrum diagram (b) Afterglow decay spectrum diagram of the phosphor obtained in Example 7;

[0026] Figure 8 Afterglow decay spectrum diagrams of the phosphors obtained in Comparative Example 1 (a) and Example 2 (b). Detailed Embodiments

[0027] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] Example 1

[0029] In this embodiment, a ZnS:0.04KBr,0.0015Mn 2+ ,0.0005Cu 2+ material is synthesized, and its preparation method is as follows:

[0030] S1. Weigh 9.7460 g of ZnS, 0.4760 g of KBr, 0.0172 g of MnCO3, and 0.0012 g of CuSO4·5H2O. Place the weighed KBr in an evaporating dish, add an appropriate amount of distilled water to dissolve it, and add the weighed ZnS and MnCO3 powders. Place it in an oven at 80 °C until it is dried.

[0031] S2. Transfer the dried powder to a mortar, add the weighed CuSO4·5H2O and grind it thoroughly for about 30 min. After mixing evenly, put it into a corundum crucible and place it in a sagger with carbon powder pressed at the bottom. Send it into a high-temperature box furnace and heat it to 900 °C for reaction for 2.5 h. After cooling to room temperature with the furnace, grind it evenly to obtain the target phosphor.

[0032] Among them, the high-temperature box furnace in step S2 specifically controls the temperature in the furnace by the following procedure:

[0033] The first stage: 40 °C → 500 °C, 100 min;

[0034] The second stage: 500 °C → 800 °C, 30 min;

[0035] The third stage: 800 °C → 900 °C, 25 min;

[0036] The fourth stage: 900 °C, 150 min (holding time);

[0037] The fifth stage: 900 °C → 800 °C, 25 min;

[0038] The sixth stage: The program stops and cools naturally.

[0039] The multicolor phosphor prepared in Example 1 shows green and yellow-green respectively under the irradiation of 302 nm and 365 nm ultraviolet lamps, and the color coordinates are (0.274, 0.401) and (0.319 and 0.437) respectively. Its fluorescence spectrum (normalized) and color coordinates are as Figure 1 shown in (a) and Figure 1As shown in (c). After removing the excitation, the displayed afterglow color is different from its corresponding excitation color, and the afterglow colors under different excitations are also different. After the de-excitation of 302 nm and 365 nm, yellow and yellowish green are presented respectively, and the color coordinates are (0.352, 0.473) and (0.346 and 0.500) respectively. The afterglow spectrum (normalized) and color coordinates are as Figure 1 in (b) and Figure 1 in (c). The afterglow decay time also reaches more than 20 s, as Figure 1 shown in (d).

[0040] Example 2

[0041] In this example, a kind of ZnS: 0.04KCl, 0.0015Mn 2+ , 0.0001Ag + is synthesized, and its preparation method is as follows:

[0042] S1. Weigh 9.7460 g of ZnS, 0.2980 g of KCl, 0.0172 g of MnCO3, and 0.0016 g of AgNO3. Place the weighed KCl in an evaporating dish, add an appropriate amount of distilled water to dissolve it, and then add the weighed ZnS and MnCO3 powders. Place them in an oven at 80 °C until dried.

[0043] S2. Transfer the dried powder to a mortar, add the weighed AgNO3 and grind it thoroughly for about 30 min. After mixing evenly, load it into a corundum crucible, and place it in a box furnace with carbon powder pressed at the bottom. Send it into the high-temperature box furnace and raise the temperature to 800 °C for reaction for 2.5 h. After cooling to room temperature with the furnace, grind it evenly to obtain the target phosphor.

[0044] Among them, the high-temperature box furnace in step S2 specifically controls the furnace temperature by the following procedure:

[0045] The first stage: 40 °C → 500 °C, 100 min;

[0046] The second stage: 500 °C → 800 °C, 30 min;

[0047] The third stage: 800 °C, 150 min (holding time);

[0048] The fourth stage: The program stops and cools naturally.

[0049] The phosphor prepared in Example 2 exhibits pinkish white and pink under 302 nm and 365 nm UV lamp irradiation respectively, with color coordinates of (0.311, 0.232) and (0.376, 0.296). After removing the excitation, the displayed afterglow color is different from its corresponding excitation color. The 365 nm de-excitation shows orange-yellow with a color coordinate of (0.467, 0.389). Its fluorescence spectrum (normalized), afterglow spectrum (normalized) and color coordinates are as shown in Figure 2 (a) and Figure 2 (c). The afterglow decay time reaches more than 5 s, as shown in Figure 2 (b).

[0050] Example 3

[0051] In this example, a ZnS:0.04CaBr2,0.0015Mn 2+ ,0.0003Tm 3+ material is synthesized, and its preparation method is as follows:

[0052] S1. Weigh 9.7460 g of ZnS, 0.0172 g of MnCO3, 0.0116 g of Tm2O3, and prepare a 0.5 mol / L standard CaBr2 solution. Weigh 8 mL of the CaBr2 standard solution into an evaporating dish, add the weighed ZnS and MnCO3 powders, and place them in an oven at 80 °C until dried.

[0053] S2. Transfer the dried powder to a mortar, add the weighed Tm2O3 and grind it thoroughly for about 30 min. After mixing evenly, load it into a corundum crucible, place it in a sagger with carbon powder at the bottom, and send it into a high-temperature box furnace. Heat it to 850 °C and react for 2.5 h. After cooling to room temperature with the furnace, grind it evenly to obtain the target phosphor.

[0054] Among them, the high-temperature box furnace in step S2 specifically controls the furnace temperature by the following procedure:

[0055] The first stage: 40 °C → 500 °C, 100 min;

[0056] The second stage: 500 °C → 800 °C, 30 min;

[0057] The third stage: 800 °C → 850 °C, 12.5 min;

[0058] The fourth stage: 850 °C, 150 min (holding time);

[0059] The fifth stage: 850 °C → 800 °C, 12.5 min;

[0060] The sixth stage: The program stops and cools naturally.

[0061] The multicolor phosphor prepared in Example 3 exhibits white and yellow under 302 nm and 365 nm ultraviolet light irradiation respectively, and the color coordinates are (0.308, 0.278) and (0.501, 0.411) respectively. After removing the excitation, the displayed afterglow color is different from its corresponding excitation color. The afterglow of 365 nm de-excitation presents orange-yellow, and the color coordinate is (0.549, 0.434). Its fluorescence spectrum (normalized), afterglow spectrum (normalized) and color coordinates are as Figure 3 shown in (a) and Figure 3 shown in (c). The afterglow decay time also reaches more than 5 s, as shown in Figure 3 shown in (b).

[0062] Example 4

[0063] In this example, a ZnS:0.04KBr,0.001Mn 2+ ,0.0001Er 3+ material was synthesized, and its preparation method is as follows:

[0064] S1. Weigh 9.7460 g of ZnS, 0.4760 g of KBr, 0.0115 g of MnCO3, and 0.0038 g of Er2O3. Place the weighed KBr in an evaporating dish, add an appropriate amount of distilled water to dissolve it, and add the weighed ZnS and MnCO3 powders. Place it in an oven at 80 °C until it is dried.

[0065] S2. Transfer the dried powder to a mortar, add the weighed Er2O3 and grind it thoroughly for about 30 min. After mixing evenly, load it into a corundum crucible, and place it in a sagger with carbon powder at the bottom. Send it into a high-temperature box furnace and raise the temperature to 1100 °C for reaction for 2 h. After cooling to room temperature with the furnace, grind it evenly to obtain the target phosphor.

[0066] Among them, the high-temperature box furnace in step S2 specifically controls the furnace temperature using the following procedure:

[0067] The first stage: 40 °C → 500 °C, 100 min;

[0068] The second stage: 500 °C → 800 °C, 30 min;

[0069] The third stage: 800 °C → 1000 °C, 50 min;

[0070] The fourth stage: 1000 °C → 1100 °C, 35 min;

[0071] The fourth stage: 1100 °C, 120 min (holding time);

[0072] The fifth stage: from 1100 °C to 1000 °C, for 35 min;

[0073] The sixth stage: from 1000 °C to 800 °C, for 50 min;

[0074] The seventh stage: the program stops and cools down naturally.

[0075] The multicolor phosphor prepared in Example 4 exhibits green and yellowish-green respectively under the irradiation of 302 nm and 365 nm ultraviolet lamps, and the color coordinates are (0.291, 0.366) and (0.329, 0.401) respectively. After removing the excitation, the displayed afterglow color is different from its corresponding excitation color. The de-excitation of 365 nm shows yellow, and the color coordinate is (0.354, 0.490). Its fluorescence spectrum, afterglow spectrum and color coordinates are as Figure 4 shown in (a) and Figure 4 shown in (c). The afterglow decay time also reaches more than 30 s, as shown in Figure 4 shown in (b).

[0076] Example 5

[0077] In this example, a ZnS:0.02KBr,0.02CaBr2,0.002Mn 2+ ,0.0003Sm 3+ material is synthesized, and its preparation method is as follows:

[0078] S1. Weigh 9.7460 g of ZnS, 0.2380 g of KBr, 0.0230 g of MnCO3, and 0.0105 g of Sm2O3. Place the weighed KBr in an evaporating dish, add an appropriate amount of distilled water to dissolve it, and prepare a 0.5 mol / L standard solution of CaBr2. Weigh 4 mL of the CaBr2 standard solution into the evaporating dish, and add the weighed ZnS and MnCO3 powders. Place it in an oven at 80 °C until it is dried.

[0079] S2. Transfer the dried powder to a mortar, add the weighed Sm2O3 and grind it thoroughly for about 30 min. After mixing evenly, load it into a corundum crucible and place it in a sagger with carbon powder at the bottom. Send it into a high-temperature box furnace and raise the temperature to 850 °C for reaction for 2.5 h. After cooling to room temperature with the furnace, grind it evenly to obtain the target phosphor.

[0080] Among them, the high-temperature box furnace in step S2 specifically controls the temperature in the furnace by the following program:

[0081] The first stage: from 40 °C to 500 °C, for 100 min;

[0082] The second stage: from 500 °C to 800 °C, for 30 min;

[0083] The third stage: 800 °C → 850 °C, 12.5 min;

[0084] The fourth stage: 850 °C, 150 min (holding time);

[0085] The fifth stage: 850 °C → 800 °C, 12.5 min;

[0086] The sixth stage: The program stops and cools naturally.

[0087] KBr can be incorporated into the ZnS lattice to generate substitutional defects, enhancing the blue-green emission. CaBr2 mainly acts as a flux to accelerate the reaction process and regulate the concentrations of the two phases, thereby enhancing the blue-green emission. Therefore, as Figure 5 shown, the synergistic effect of KBr and CaBr2 can further enhance the luminescence intensity, afterglow intensity, and afterglow decay time of the phosphor.

[0088] Example 6

[0089] In this example, a ZnS:0.02KBr, 0.02CaBr2, 0.0015Mn 2+ ,0.0001Cu 2+ , 0.0001Ag + material is synthesized, and its preparation method is as follows:

[0090] S1. Weigh 9.7460 g of ZnS, 0.2380 g of KBr, 0.0172 g of MnCO3, 0.0025 g of CuSO4·5H2O, and 0.0017 g of AgNO3. Place the weighed KBr in an evaporating dish, add an appropriate amount of distilled water to dissolve it, and prepare a 0.5 mol / L standard CaBr2 solution. Weigh 4 mL of the CaBr2 standard solution into the evaporating dish, and add the weighed ZnS and MnCO3 powders. Place it in an oven at 80 °C until it is dried.

[0091] S2. Transfer the dried powder to a mortar, add the weighed MnCO3 and AgNO3, and grind them thoroughly for about 30 min. After mixing evenly, load them into a corundum crucible, and place it in a box furnace with carbon powder pressed at the bottom. Send it into a high-temperature box furnace and raise the temperature to 850 °C for reaction for 2.5 h. After cooling to room temperature with the furnace, grind it evenly to obtain the target phosphor.

[0092] Among them, the high-temperature box furnace in step S2 specifically controls the temperature in the furnace using the following procedure:

[0093] The first stage: 40 °C → 500 °C, 100 min;

[0094] The second stage: 500 °C → 800 °C, 30 min;

[0095] The third stage: 800 °C → 850 °C, 12.5 min;

[0096] The fourth stage: 850 °C, 150 min (holding time);

[0097] The fifth stage: 850 °C → 800 °C, 12.5 min;

[0098] The sixth stage: The program stops and cools naturally.

[0099] As Figure 6 shown, doping with Ag + can significantly improve the luminescence intensity and afterglow time of the phosphor.

[0100] Example 7

[0101] In this example, a ZnS: 0.02KBr, 0.02CaBr2, 0.0015Mn 2+ , 0.0001 Ag + , 0.0001Er 3+ material is synthesized, and its preparation method is as follows:

[0102] S1. Weigh 9.7460 g of ZnS, 0.2380 g of KBr, 0.0172 g of MnCO3, 0.0017 g of AgNO3, and 0.0038 g of Er2O3. Place the weighed KBr in an evaporating dish, add an appropriate amount of distilled water to dissolve it, and prepare a 0.5 mol / L CaBr2 standard solution. Weigh 4 mL of the CaBr2 standard solution into the evaporating dish, and add the weighed ZnS and MnCO3 powders. Place it in an oven at 80 °C until it is dried.

[0103] S2. Transfer the dried powder to a mortar, add the weighed Er2O3 and AgNO3, and grind them thoroughly for about 30 min. After mixing evenly, put them into a corundum crucible, and place it in a box furnace with carbon powder at the bottom. Heat it to 850 °C in the high-temperature box furnace and react for 2.5 h. After cooling to room temperature with the furnace, grind it evenly to obtain the target phosphor.

[0104] Among them, the high-temperature box furnace in step S2 specifically controls the temperature in the furnace using the following procedure:

[0105] The first stage: 40 °C → 500 °C, 100 min;

[0106] The second stage: 500 °C → 800 °C, 30 min;

[0107] The third stage: 800 °C → 850 °C, 12.5 min;

[0108] Fourth stage: 850 °C, 150 min (holding time);

[0109] Fifth stage: 850 °C → 800 °C, 12.5 min;

[0110] Sixth stage: The program stops and the temperature drops naturally.

[0111] As Figure 7 shown, the incorporation of Er 3+ can significantly improve the phosphorescence intensity and afterglow time of the phosphor.

[0112] Comparative Example 1

[0113] This comparative example synthesizes a ZnS:0.04KBr, 0.0015Mn 2+ , 0.0005Cu 2+ material. The difference in its preparation method from that of Example 2 is only that: in step S2, after the temperature of the high-temperature box furnace rises to 800 °C, the box door is opened, the crucible is placed in the high-temperature box furnace for reaction for 2.5 h. After the reaction is completed, the box door is opened, the crucible is taken out and cooled at room temperature to obtain the phosphor.

[0114] As Figure 8 shown in (a) and (b) therein, the comparison of the afterglow decay times of the phosphors prepared in Comparative Example 1 and Example 2 respectively. The phosphor prepared by the slow-in (furnace) and slow-out (furnace) type high-temperature solid-phase method of the embodiment of the present invention can effectively improve the afterglow duration and is suitable for commercial anti-counterfeiting applications.

[0115] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. An ultra-long afterglow zinc sulfide fluorescent anti-counterfeiting material with simultaneously adjustable fluorescence and afterglow, characterized in that: The fluorescent anti-counterfeiting material contains ZnS: a KA, b CaB2, y Mn 2+ , z R n+ , Among them, A is selected from at least one of Cl, Br, and I, B is selected from at least one of Cl, Br, and I, and R n+ is selected from 2+ Cu + , Ag 3+ , Er 3+ , Sm 3+ , Tm z and at least one of them, 0 ≤ a ≤ 0.1, 0 ≤ b ≤ 0.1, 0 < y ≤ 0.004, 0 < z ≤ 0.001, and a and b are not both 0; The preparation method of the fluorescent anti-counterfeiting material comprises the following steps: S1. Mix the KA solution, CaB2 solution, ZnS, and Mn salt in proportion and dry them at 60 - 100 °C. After drying, add the corresponding oxide and / or carbonate and grind them evenly to obtain the precursor powder; n+ ​ S2. Place the precursor powder in a box furnace, heat it up to 750-1100 °C together and calcine for 2-4 h, grind it evenly after cooling to room temperature with the furnace; In step S2, the heating rate is 2-12 °C / min; In step S2, heat up, calcine and cool in a CO atmosphere.

2. A long afterglow zinc sulfide fluorescent anti-counterfeiting material with simultaneously adjustable fluorescence and afterglow, characterized in that: 0 < a ≤ 0.1, 0 < b ≤ 0.

1.

3. A long afterglow zinc sulfide fluorescent anti-counterfeiting material with simultaneously adjustable fluorescence and afterglow, characterized in that: The CO atmosphere is provided by carbon powder.

4. Application of an ultra-long afterglow zinc sulfide fluorescent anti-counterfeiting material with simultaneously adjustable fluorescence and afterglow in the preparation of anti-counterfeiting products according to any one of claims 1-3.

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