Four-mode anti-counterfeiting glass, preparation method and application thereof

Abstract

The present invention relates to the field of optical functional materials and display technology, and discloses a four-mode anti-counterfeiting glass, a preparation method, and its application in the field of anti-counterfeiting. The molar ratio of the glass components is SiO2: 30-60 mol%, Na2CO3: 5-20 mol%, Al2O3: 5-30 mol%, CaCO3: 3-10 mol%, NaF: 3-20 mol%, LuF3: 3-20 mol%, and EuF3: 0-5 mol%. The four-mode anti-counterfeiting glass has four anti-counterfeiting modes: fluorescent luminescence color, long afterglow luminescence color, light-stimulated recovery of long afterglow, and heat-stimulated recovery of long afterglow. EuF3 is used as the anti-counterfeiting mode. 2+ / Eu 3+ The preparation method includes the steps of precisely weighing the raw materials, thoroughly mixing them, adding a reducing agent powder, melting them in a high-temperature furnace, casting them into a mold, quenching them, cutting and polishing them, and then treating them in a low-temperature furnace. This invention has the advantages of low cost, high stability, high luminous efficiency, adjustable shape, and environmental friendliness for use in the anti-counterfeiting field.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric functional materials and anti-counterfeiting technology, in particular to a four-mode anti-counterfeiting glass, a preparation method and application thereof. Background Art

[0002] With the rapid development of information technology and the globalization of the commodity market, the problem of counterfeiting and illegal reproduction of goods is becoming increasingly serious. The proliferation of counterfeit products not only infringes on the rights of brand owners but also threatens consumer safety and the normal order of the market. Traditional anti-counterfeiting strategies such as watermarks and barcodes are easily copied and cannot meet the growing demand for anti-counterfeiting. To prevent the circulation of counterfeit and substandard products, optical anti-counterfeiting technology has been widely used as an effective anti-counterfeiting measure.

[0003] Single-mode optical anti-counterfeiting, such as relying solely on the identification of the luminescent color (wavelength) of the material, is an anti-counterfeiting method that is easily cracked and copied. Combining two or more modes of anti-counterfeiting materials is very helpful in solving problems such as the low level of single anti-counterfeiting. The Chinese patent application publication number CN118580705A proposes a dual anti-counterfeiting method of structural color anti-counterfeiting under natural light and fluorescent anti-counterfeiting under ultraviolet excitation, specifically using mesoporous silica to load halogen perovskite fluorescent particles. However, three different fluorescent particles need to be prepared. At the same time, the environmental stability of halogen perovskite is relatively poor, and there are strict requirements on the application environment, service life and life span. The Chinese patent application publication number 118580706A discloses a dual-mode composite anti-counterfeiting coating. Oxide is used as raw material, and a stable phosphor is obtained after calcination. After adding epoxy resin and curing agent for curing, pearlescent pigment is then sprayed to obtain a composite anti-counterfeiting coating. However, this dual-mode anti-counterfeiting still requires two different fluorescent materials, which on the one hand increases the cost and difficulty of preparation. On the other hand, in actual applications, the double-layer composite structure is easy to separate, further limiting its practical application.

[0004] Therefore, developing multi-mode anti-counterfeiting for a single material is an urgent problem to be solved in current practical applications. Summary of the Invention

[0005] In the field of anti-counterfeiting technology, existing optical anti-counterfeiting materials often rely on a single anti-counterfeiting mode, such as relying solely on the material's luminescent color for identification. This single level of security is easily imitated and replicated, thereby reducing the anti-counterfeiting effect. Furthermore, existing anti-counterfeiting materials may suffer from insufficient stability, low luminous efficiency, non-adjustable shape, or environmental unfriendliness. Therefore, the development of a new anti-counterfeiting material that can combine multiple anti-counterfeiting modes, improve stability and luminous efficiency, and be shape-adjustable and environmentally friendly has become a pressing technical challenge in the field of anti-counterfeiting technology.

[0006] The purpose of the present invention is to provide a stable optical anti-counterfeiting material. This single material has four anti-counterfeiting modes, solving the current technical problem that multi-mode anti-counterfeiting requires the combination of at least two types of materials.

[0007] The present invention provides a four-mode anti-counterfeit glass, wherein the molar ratios of the components of the four-mode anti-counterfeit glass are: SiO2: 30-60 mol%, Na2CO3: 5-20 mol%, Al2O3: 5-30 mol%, CaCO3: 3-10 mol%, NaF: 3-20 mol%, LuF3: 3-20 mol%, and EuF3: 0-5 mol%.

[0008] In the above solution, the four-mode anti-counterfeiting glass has four different anti-counterfeiting modes, namely, fluorescent luminous color, long afterglow luminous color, light-stimulated long afterglow recovery, and heat-stimulated long afterglow recovery.

[0009] In the above solution, the four-mode anti-counterfeiting glass is made of Eu 2+ / Eu 3+ The luminous center.

[0010] In the above scheme, the four-mode anti-counterfeiting glass is reduced to Eu by a reducing agent or a reducing atmosphere. 3+ Partially reduced to Eu 2+ , forming Eu 2+ / Eu 3+ Luminous center.

[0011] The present invention also provides a method for preparing four-mode anti-counterfeiting glass, comprising the following steps:

[0012] S1. Accurately weigh the raw materials and mix them thoroughly to obtain a mixed powder I;

[0013] S2 weighed an appropriate amount of reducing agent powder, added to the mixed powder I, and mixed thoroughly to obtain a mixed powder II;

[0014] S3. The mixed powder II is transferred to a high-temperature furnace, the furnace temperature is maintained at a temperature a1, and kept warm for a period of time b1 until the mixed powder is completely melted;

[0015] S4. The melt is poured onto a mold at a temperature of a2, and a flat mold at a temperature of a2 is used above to apply stress to the melt to obtain a quenched glass I;

[0016] S5. After cutting and polishing, glass I is transferred to a low-temperature furnace at a temperature of a3 and kept warm for a period of time b2 to obtain glass II, thereby obtaining four-mode anti-counterfeiting glass.

[0017] In the above solution, the reducing agent powder includes but is not limited to Al powder and reducing carbon powder, and the amount of the reducing agent added is ≤10 mol%.

[0018] In the above scheme, temperature a1 is 1200-1550°C, temperature a2 is 200-400°C, temperature a3 is 200-400°C, time b1 is 1-2 hours, and time b2 is 4-48 hours.

[0019] The present invention also provides a method for preparing four-mode anti-counterfeiting glass, comprising the following steps:

[0020] S1. Accurately weigh the raw materials and mix them thoroughly to obtain a mixed powder I;

[0021] S2. The mixed powder I is transferred to a high-temperature furnace, the furnace temperature is maintained at a temperature a4, heat for a period of time b3, until the mixed powder is completely melted;

[0022] S3. The melt is poured onto a mold at a temperature of a5, and a flat mold at a temperature of a5 is used above to apply stress to the melt to obtain quenched glass III;

[0023] S4. After cutting and polishing the glass III, it was transferred to a low-temperature furnace at a temperature of a6 and kept warm for a period of time b4 to obtain glass IV;

[0024] Four-mode anti-counterfeit glass made with S5-1 or S5-2:

[0025] S5-1. The glass IV is placed in a tube furnace and passed through a N2 / H2 mixture, the furnace temperature a7, and kept warm for a period of time b5 to obtain glass V, that is, four-mode anti-counterfeiting glass;

[0026] S5-2. Place glass IV in step S4 in a crucible box with a lid, fill the reducing agent powder around the glass, place the crucible box in a low-temperature furnace, the furnace temperature is a8, and keep it warm for a period of time b6 to obtain glass VI, that is, to obtain four-mode anti-counterfeiting glass.

[0027] In the above scheme, temperature a4 is 1200-1550°C, temperature a5 is 200-400°C, temperature a6 is 200-400°C, and temperatures a7 and a8 are 300-400°C.

[0028] In the above scheme, time b3 is 1 to 2 hours, time b4 is 4 to 48 hours, and time b5 and b6 are 8 to 48 hours.

[0029] In the above scheme, Eu 3+ Partially reduced to Eu 2+ , forming Eu 2+ / Eu 3+ Luminous center.

[0030] Because the present invention adopts the above technical solution, it has the following beneficial effects:

[0031] First, a single material achieves four modes of optical anti-counterfeiting technology. Compared to single-mode optical anti-counterfeiting, multi-mode optical anti-counterfeiting offers a higher level of security and is more difficult to crack and replicate. However, current multi-mode anti-counterfeiting requires a composite of at least two fluorescent materials. The glass of this invention simultaneously possesses four distinct optical anti-counterfeiting modes, making it more practical.

[0032] Second, stability and cost. In terms of stability, on the one hand, the selected glass matrix has the characteristics of resistance to water, oxygen, high-energy radiation, heat, etc., and has high stability. On the other hand, the glass plays a protective role on the luminescent center. After high-temperature heat treatment, the thermal stability of the anti-counterfeiting glass is more outstanding. In terms of cost and cycle, the raw materials used in the present invention are low in cost, the preparation method is simple and the cycle is short. Unlike phosphors, four-mode anti-counterfeiting glass does not require additional packaging. The glass preparation method and heat treatment method adopted in the present invention are based on mature glass preparation process technology and are very suitable for industrial production. Compared with powdered phosphors, the present invention is a block solid, which is easy to recycle and process, and is environmentally friendly, complies with national policies, and is easy to promote and use.

[0033] Third, the luminescent center of the scintillator of the present invention is Eu 2+ / Eu 3+ On the one hand, Eu ions have high luminescence efficiency and can fully match commercial Si and semiconductor detectors.

[0034] Fourth, the four-mode anti-counterfeiting glass of the present invention can be processed into a desired shape according to the application scenario, which has great flexibility.

[0035] Fifth, the present invention provides a component ratio of the glass matrix, which can optimize the luminescence performance and provide a technical control method for industrial production and application.

[0036] The present invention provides a method for realizing Eu 2+ The existing method specifically adopts the addition of reducing agents such as A1 powder and reducing carbon powder; the present invention also provides a strategy for controlling the amount of reducing agent added, which helps to optimize Eu 2+ concentration, regulating the emission wavelength.

[0037] The present invention also provides the melting temperature and subsequent heat treatment temperature of the four-mode anti-counterfeiting glass, which can optimize and regulate the luminescence performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1-5 are X-ray diffraction patterns of Examples 1-5 of the present invention.

[0039] Figure 2 This is the excitation spectrum of Example 1-2 of the present invention.

[0040] Figure 3 This is the emission spectrum of Example 1-2 of the present invention.

[0041] Figure 4 This is the excitation spectrum of embodiment 3-4 of the present invention.

[0042] Figure 5 The emission spectra of Examples 3-4 of the present invention are shown.

[0043] Figure 6 1 is the photoluminescence spectrum of Example 1 of the present invention at different excitation wavelengths.

[0044] Figure 7 These are the thermoluminescence spectra of Examples 1 and 3 of the present invention.

[0045] Figure 8 These are the long afterglow spectra of Examples 1 and 3 of the present invention.

[0046] Figure 9 These are the corresponding luminescence images after filling the mold in the embodiment, the long afterglow image, the photo of the complete attenuation of the afterglow after 5 minutes, the afterglow luminescence image restored by 980nm laser, and the afterglow luminescence image restored under thermal stimulation.

[0047] Figure 10 Time@temperature information encryption mode. DETAILED DESCRIPTION

[0048] The following is a detailed description of the embodiments of the present invention. Although the present invention will be described and illustrated in conjunction with certain specific embodiments, it should be noted that the present invention is not limited to these embodiments. On the contrary, modifications or equivalent substitutions of the present invention are intended to fall within the scope of the claims of the present invention.

[0049] In addition, in order to better illustrate the present invention, numerous specific details are given in the following detailed description. It will be understood by those skilled in the art that the present invention can also be implemented without these specific details.

[0050] The present invention provides a four-mode anti-counterfeiting glass, wherein the molar ratio of the components of the four-mode anti-counterfeiting glass is:

[0051] SiO2: 30~60mol%; Na2CO3: 5~20mol%; Al2O3: 5~30mol%; CaCO3: 3~10mol%; NaF: 3~20mol%; LuF3: 3~20mol%; EuF3: 0~5mol%;

[0052] Preferred glass composition 1: SiO2: 45 mol%, Na2CO3: 10 mol%, Al2O3: preferably 15 mol%, CaCO3: 10 mol%, NaF: 5 mol%, LuF3: 8 mol%, EuF3: 2 mol%;

[0053] Preferred glass component 2: SiO2: 55 mol%, Na2CO3: 12 mol%, Al2O3: 8 mol%, CaCO3: 4 mol%, NaF: 13 mol%, LuF3: 4 mol%, EuF3: 4 mol%;

[0054] In the above solution, the four-mode anti-counterfeiting glass has four different anti-counterfeiting modes, namely, fluorescent luminous color, long afterglow luminous color, light-stimulated long afterglow recovery, and heat-stimulated long afterglow recovery.

[0055] In the above solution, the four-mode anti-counterfeiting glass is made of Eu 2+ / Eu 3+ The luminous center.

[0056] In the above scheme, the four-mode anti-counterfeiting glass is reduced to Eu by a reducing agent or a reducing atmosphere. 3+ Partially reduced to Eu 2+ , forming Eu 2+ / Eu 3+ Luminous center.

[0057] The present invention also provides a method for preparing four-mode anti-counterfeiting glass, comprising the following steps:

[0058] S1. Accurately weigh the raw materials and mix them thoroughly to obtain a mixed powder I;

[0059] S2 weighed an appropriate amount of reducing agent powder, added to the mixed powder I, and mixed thoroughly to obtain a mixed powder II;

[0060] S3. The mixed powder II is transferred to a high-temperature furnace, the furnace temperature is maintained at a temperature a1, and kept warm for a period of time b1 until the mixed powder is completely melted; wherein the temperature a1 is 1200-1550 ℃, optionally 1200 ℃, 1420 ℃, 1550 ℃, time b1 is 1 to 2 hours, optionally 1 hour, 2 hours;

[0061] S4. The melt is poured onto a mold at a temperature of a2, and a flat mold at a temperature of a2 is used above to apply stress to the melt to obtain a quenched glass I; wherein the temperature a2 is 200-400 ℃, which may be 200 ℃, 300 ℃, 400 ℃;

[0062] S5. After cutting and polishing, glass I is transferred to a low-temperature furnace at a temperature a3 and held for a period b2 to obtain glass II, thereby obtaining four-mode anti-counterfeiting glass. The temperature a3 is 200-400°C, and can be 200°C, 300°C, or 600°C; the time b2 is 4-48 hours, and can be 4, 24, or 48 hours.

[0063] In the above solution, the reducing agent powder includes but is not limited to Al powder and reducing carbon powder, and the added amount of the reducing agent is ≤10 mol%, and can be optionally 3 mol%.

[0064] The present invention also provides a method for preparing four-mode anti-counterfeiting glass, comprising the following steps:

[0065] S1. Accurately weigh the raw materials and mix them thoroughly to obtain a mixed powder I;

[0066] S2. The mixed powder I is transferred to a high-temperature furnace, the furnace temperature is maintained at a temperature a4, and kept warm for a period of time b3 until the mixed powder is completely melted; wherein the temperature a4 is 1200-1550 ℃, which may be 1200 ℃, 1420 ℃, 1550 ℃, and the time b3 is 1 to 2 hours, optionally 1 hour, 2 hours;

[0067] S3. The melt is poured onto a mold at a temperature of a5, and a flat mold at a temperature of a5 is used above to apply stress to the melt to obtain quenched glass III; wherein the temperature a5 is 200-400 ℃, which may be 200 ℃, 300 ℃, 400 ℃;

[0068] S4. After cutting and polishing the glass III, it was transferred to a low-temperature furnace at a furnace temperature of a6 and kept warm for a period of time b4 to obtain glass IV; wherein the temperature a6 is 200-400°C, which may be 200°C, 400, or 600°C; and the time b4 is 4 to 48 hours, which may be 4, 12, or 48 hours.

[0069] Four-mode anti-counterfeit glass made with S5-1 or S5-2:

[0070] S5-1. Glass IV is placed in a tube furnace and passed through a N2 / H2 mixture, the furnace temperature a7, and kept warm for a period of time b5 to obtain glass V, i.e., four-mode anti-counterfeit glass; temperature a7 is 300-400 ℃, which can be 300 ℃, 400 ℃, time b5 is 8 to 48 hours, which can be 8 hours, 12 hours, 48 ​​hours;

[0071] S5-2. Place glass IV from step S4 in a covered crucible box, fill the surrounding area with reducing agent powder, and place the crucible box in a low-temperature furnace at a temperature a8 for a holding time b6 to obtain glass VI, thus obtaining the four-mode anti-counterfeit glass. The temperature a8 is 300-400°C, preferably 300°C or 400°C, and the holding time b6 is 8-48 hours, preferably 8, 12, or 48 hours.

[0072] In the above scheme, Eu 3+ Partially reduced to Eu 2+ , forming Eu 2+ / Eu 3+ Luminous center.

[0073] Example 1

[0074] (1) Accurately weigh the raw materials according to SiO2: 45 mol%, Na2CO3: 10 mol%, Al2O3: 15 mol%, CaCO3: 10 mol%, NaF: 7 mol%, LuF3: 8 mol%, EuF3: 2 mol%; Al: 3 mol%, mix them thoroughly, and transfer them into a crucible;

[0075] (2) The crucible is transferred to a high-temperature furnace, the furnace temperature is maintained at 1420°C, and the temperature is kept for 1 hour until the mixed powder in the crucible is completely molten;

[0076] (3) pouring the above molten liquid onto a mold at 300°C, and applying pressure to the glass liquid poured onto the mold using a 300°C iron plate to quench the molten liquid into glass;

[0077] (4) The glass obtained above is quickly transferred to an annealing furnace and annealed. The annealing furnace temperature is set at 300°C and the annealing time is 24 hours. After naturally cooling to room temperature, the glass is cut and polished to obtain a four-mode anti-counterfeiting glass.

[0078] Example 2

[0079] (1) Accurately weigh the raw materials according to SiO2: 45 mol%, Na2CO3: 10 mol%, Al2O3: 18 mol%, CaCO3: 10 mol%, NaF: 7 mol%, LuF3: 8 mol%, and EuF3: 2 mol%, mix them thoroughly, and transfer them into a crucible;

[0080] (2) The crucible is transferred to a high-temperature furnace, the furnace temperature is maintained at 1420°C, and the temperature is kept for 1 hour until the mixed powder in the crucible is completely molten;

[0081] (3) pouring the above molten liquid onto a mold at 300°C, and applying pressure to the glass liquid poured onto the mold using a 300°C iron plate to quench the molten liquid into glass;

[0082] (4) The glass obtained above was quickly transferred to an annealing furnace for annealing. The annealing furnace temperature was set at 400° C. and the annealing time was 4 hours.

[0083] (5) After cutting and polishing, the glass was transferred to a tube furnace. The temperature in the furnace was set to 400°C, and a N2 / H2 mixture was introduced at a flow rate of 100 sccm. The temperature was maintained for 12 hours. After cooling naturally to room temperature, the four-mode anti-counterfeiting glass was obtained.

[0084] Example 3

[0085] (1) Accurately weigh the raw materials according to SiO2: 45 mol%, Na2CO3: 10 mol%, Al2O3: 15 mol%, CaCO3: 10 mol%, NaF: 5 mol%, LuF3: 8 mol%, EuF3: 2 mol%; carbon powder: 5 mol%, mix them thoroughly, and transfer them into a crucible;

[0086] (2) The crucible is transferred to a high-temperature furnace, the furnace temperature is maintained at 1420°C, and the temperature is kept for 1 hour until the mixed powder in the crucible is completely molten;

[0087] (3) pouring the above molten liquid onto a mold at 300°C, and applying pressure to the glass liquid poured onto the mold using a 300°C iron plate to quench the molten liquid into glass;

[0088] (4) The glass obtained above is quickly transferred to an annealing furnace and annealed. The annealing furnace temperature is set at 300°C and the annealing time is 24 hours. After naturally cooling to room temperature, the glass is cut and polished to obtain a four-mode anti-counterfeiting glass.

[0089] Example 4

[0090] (1) Accurately weigh the raw materials according to SiO2: 45 mol%, Na2CO3: 10 mol%, Al2O3: 18 mol%, CaCO3: 10 mol%, NaF: 7 mol%, LuF3: 8 mol%, and EuF3: 2 mol%, mix them thoroughly, and transfer them into a crucible;

[0091] (2) The crucible is transferred to a high-temperature furnace, the furnace temperature is maintained at 1420°C, and the temperature is kept for 1 hour until the mixed powder in the crucible is completely molten;

[0092] (3) pouring the above molten liquid onto a mold at 300°C, and applying pressure to the glass liquid poured onto the mold using a 300°C iron plate to quench the molten liquid into glass;

[0093] (4) The glass obtained above was quickly transferred to an annealing furnace for annealing. The annealing furnace temperature was set at 400° C. and the annealing time was 4 hours.

[0094] (5) After cutting and polishing, the glass is transferred to a crucible with a lid. Carbon powder is spread around the glass, and the crucible is transferred to a low-temperature furnace. The furnace temperature is set to 400°C and kept warm for 12 hours. After cooling naturally to room temperature, the four-mode anti-counterfeiting glass is obtained.

[0095] Example 5

[0096] (1) Accurately weigh the raw materials according to SiO2: 55 mol%, Na2CO3: 12 mol%, Al2O3: 8 mol%, CaCO3: 4 mol%, NaF: 13 mol%, LuF3: 4 mol%, EuF3: 4 mol%; Al: 3 mol%, mix them thoroughly, and transfer them into a crucible;

[0097] (2) The crucible is transferred to a high-temperature furnace, the furnace temperature is maintained at 1420°C, and the temperature is kept for 1 hour until the mixed powder in the crucible is completely molten;

[0098] (3) pouring the above molten liquid onto a mold at 300°C, and applying pressure to the glass liquid poured onto the mold using a 300°C iron plate to quench the molten liquid into glass;

[0099] (4) The glass obtained above is quickly transferred to an annealing furnace and annealed. The annealing furnace temperature is set at 300°C and the annealing time is 24 hours. After naturally cooling to room temperature, the glass is cut and polished to obtain a four-mode anti-counterfeiting glass.

[0100] Figure 1 Figure 2 is the XRD pattern of the anti-counterfeit glass samples obtained in Examples 1 to 4. The XRD patterns of all samples obtained in Examples 1 to 4 only exhibit diffuse peaks without sharp diffraction peaks, indicating that all the glass samples obtained do not contain nanocrystals. Even after subsequent heat treatment and the addition of Al powder, no new phases are generated.

[0101] Figure 2 The Eu of the glass sample obtained in Example 1-2 3+ The excitation spectrum of the monitored emission light is 615nm, which is a typical Eu 3+ The excitation spectrum has several similarities with Eu in the range of 300-550nm. 3+The peaks related to the 4f-4f transition of 7 F0→ 5 The luminescence peak of L6 is the strongest, while the broad peak between 250-320nm belongs to O 2- -Eu 3+ Charge transfer band. Figure 3 is Eu of the glass sample of Example 1-2 2+ The emission spectrum of the 250-425nm strong excitation band comes from Eu 2+ of 4 f7→ 4 f6 5 d1 transition. This shows that the glass sample obtained contains Eu 2+ / Eu 3+ The luminous center.

[0102] Figure 4 is the Eu of the glass sample obtained in Example 3-4 3+ The excitation spectrum of the monitored emission light is 616 nm, which is a typical Eu 3+ The glow. Figure 5 is Eu of the glass sample of Example 3-4 2+ Similar to using A1 powder as a reducing agent, using carbon powder as a reducing agent also yields the emission spectrum of Eu 2+ / Eu 3+ A glass sample with a luminescent center.

[0103] Figure 6 This is the photoluminescence spectrum of Example 1. When excited by 383nm light, the glass sample emits primarily at 460nm, while when excited by 394nm light, it emits at 615nm. Furthermore, the luminescence peak of the glass shifts significantly depending on the amount of reducing agent added. Under fluorescent light, glass appears colorless, but under ultraviolet laser light, it exhibits different colors. In practical applications, this color can be used to distinguish authenticity.

[0104] Figure 7 The thermoluminescence curve of the sample in Example 1 is shown in Figure 2. The sample was first heated for a sufficient time to clear the trapped electrons, and then excited with 365nm ultraviolet light for 2 minutes. The thermoluminescence results at a heating rate of 1°C / s are shown in Figure 2. Figure 7 The thermoluminescence curve of the sample in Example 3 is a smooth straight line, indicating that there is no obvious thermoluminescence phenomenon in the glass during the heating process.

[0105] Figure 8The long-lasting luminescence spectra of Examples 1 and 3 are shown. After 5 minutes of excitation with 365nm violet light, the sample in Example 1 exhibits long-lasting luminescence. In contrast, no long-lasting luminescence is observed in the sample in Example 3. This indicates that the presence of the reducing agent causes the sample to exhibit long-lasting luminescence.

[0106] Figure 9 The corresponding luminescence images after filling the mold in the embodiment, the long afterglow images, the photos of the complete attenuation of the afterglow after 5 minutes, the afterglow luminescence images restored by 980nm laser, and the afterglow luminescence images restored under thermal stimulation. Under fluorescent light, "ZJ" is colorless, but under ultraviolet light excitation, "Z (sample of Example 1)" shows cyan, and "J (sample of Example 2)" shows light blue. After turning off the light, "Z" and "J" emit long afterglow, and the afterglow disappears after 5 minutes. After irradiation with 980nm laser, the long afterglow can be seen to be restored. In addition, the long afterglow luminescence can also be restored under thermal stimulation of 50, 100, and 150°C. The above changes can be used in the field of anti-counterfeiting.

[0107] Figure 10 This is a time-temperature information encryption mode. After exposure to UV light, different information can be read under different external conditions. For example, after 30 seconds at 30°C (30s@30°C, designated (30, 30)), only "Z" is read, while at the coordinates (0, 200), both "Z" and "J" are read. Furthermore, the contrast between "Z" and "J" varies at different coordinates.

Claims

1. A four-mode anti-counterfeiting glass, characterized in that: The molar proportions of the components of the four-mode anti-counterfeit glass are: SiO2: 30~60mol%, Na2CO3: 5~20mol%, Al2O3: 5~30mol%, CaCO3: 3~10mol%, NaF: 3~20mol%, LuF3: 3~20mol%, and EuF3: 2~5mol%.

2. The four-mode anti-counterfeiting glass according to claim 1, characterized in that: The four-mode anti-counterfeiting glass has four different anti-counterfeiting modes: fluorescent luminous color, long afterglow luminous color, light stimulation to restore long afterglow, and heat stimulation to restore long afterglow.

3. The four-mode anti-counterfeiting glass according to claim 1, characterized in that: The four-mode anti-counterfeiting glass is made of Eu 2+ / Eu 3+ The luminous center.

4. The four-mode anti-counterfeiting glass according to claim 1, characterized in that: The four-mode anti-counterfeiting glass is reduced by a reducing agent or a reducing atmosphere. 3+ Partially reduced to Eu 2+ , forming Eu 2+ / Eu 3+ Luminous center.

5. The method for preparing the four-mode anti-counterfeiting glass according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Accurately weigh the raw materials and mix them thoroughly to obtain a mixed powder I; S2 weighed an appropriate amount of reducing agent powder, added to the mixed powder I, and mixed thoroughly to obtain a mixed powder II; S3. The mixed powder II is transferred to a high-temperature furnace, the furnace temperature is maintained at a temperature a1, and kept warm for a period of time b1 until the mixed powder is completely melted; S4. The melt is poured onto a mold at a temperature of a2, and a flat mold at a temperature of a2 is used above to apply stress to the melt to obtain a quenched glass I; S5. After cutting and polishing, glass I is transferred to a low-temperature furnace at a temperature of a3 and kept warm for a period of time b2 to obtain glass II, thereby obtaining four-mode anti-counterfeiting glass.

6. The preparation method according to claim 5, characterized in that The reducing agent powder includes but is not limited to Al powder and reducing carbon powder, and the amount of the reducing agent added is ≤10 mol%.

7. The preparation method according to claim 5, characterized in that Temperature a1 is 1200-1550 o C, temperature a2 is 200-400 o C, temperature a3 is 200-400 o C, time b1 is 1~2 hours, time b2 is 4~48 hours.

8. The method for preparing the four-mode anti-counterfeiting glass according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Accurately weigh the raw materials and mix them thoroughly to obtain a mixed powder I; S2. The mixed powder I is transferred to a high-temperature furnace, the furnace temperature is maintained at a temperature a4, heat for a period of time b3, until the mixed powder is completely melted; S3. The melt is poured onto a mold at a temperature of a5, and a flat mold at a temperature of a5 is used above to apply stress to the melt to obtain quenched glass III; S4 glass III is cut, polished, transferred to a low-temperature furnace, the furnace temperature a6, heat for a period of time b4, to obtain glass IV; Four-mode anti-counterfeit glass made with S5-1 or S5-2: S5-1. The glass IV is placed in a tube furnace and passed through a N2 / H2 mixture, the furnace temperature a7, and kept warm for a period of time b5 to obtain glass V, that is, four-mode anti-counterfeiting glass; S5-2. Place glass IV in step S4 in a crucible box with a lid, fill the reducing agent powder around the glass, place the crucible box in a low-temperature furnace, the furnace temperature is a8, and keep it warm for a period of time b6 to obtain glass VI, that is, to obtain four-mode anti-counterfeiting glass.

9. The preparation method according to claim 8, characterized in that Temperature a4 is 1200-1550 o C, temperature a5 is 200-400 o C, temperature a6 is 200-400 o C, temperature a7 and a8 are 300-400 o C.

10. The preparation method according to claim 8, characterized in that The time b3 is 1 to 2 hours, the time b4 is 4 to 48 hours, and the times b5 and b6 are 8 to 48 hours.

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