Method for applying optical switch fluorescent polymer to dynamic fluorescent anti-counterfeiting

Abstract

The invention discloses a method for applying photoswitch fluorescent polymers to dynamic fluorescent falsification prevention, which comprises the following steps: taking methyl acrylate, 1, 6-hexanediol diacrylate, a photoinitiator 819, a green fluorescent dye BDPMA and one of three photochromic spiropyrans SPMA, SPAMA and SPBMA as raw materials, and preparing three photoswitch fluorescent polymers P1, P2 and P3 in a photopolymerization manner. The P1, P2 and P3 are irradiated by ultraviolet light and placed in room-temperature darkness, red fluorescence generated by the P1, P2 and P3 can be gradually and spontaneously converted into green fluorescence, due to the structural difference of the three spiropyrans, the fluorescence discoloration rates of the three polymers show obvious difference, and a new dynamic fluorescent anti-counterfeit label is constructed by utilizing the difference. The photoswitch fluorescent polymer obtained by the invention has the advantages of simple preparation method, stable structure and good machinability, is suitable for amplification synthesis and practical application, and has wide application prospects in the fields of optical anti-counterfeiting and information encryption.

Description

Technical Field

[0001] The present invention belongs to the technical fields of chemical material preparation and display material, and in particular relates to a method for applying a light-switchable fluorescent polymer to dynamic fluorescent anti-counterfeiting. Background Art

[0002] With the continuous development of social economy and science and technology, the problem of counterfeit and inferior products has become more and more serious, causing serious damage to consumer rights and social and economic order. The development of an efficient and reliable anti-counterfeiting technology has become an urgent problem to be solved. Photoswitchable fluorescent polymers are functional polymer materials with the characteristics of light-induced reversible fluorescence changes. They usually use the photofluorescence signal changes of the photochromic compound itself (such as spiropyran, diarylethenes, etc.) in the material, or use the light-induced controllable fluorescence resonance energy transfer (FRET) between the fluorescent dye combined with the material and the photochromic compound to achieve the fluorescence reversible switching characteristics of the material.

[0003] Currently, photoswitchable fluorescent polymers show great potential for anti-counterfeiting applications due to their rapid, reversible fluorescence changes under light or heat stimulation (e.g., from green to red), excellent luminescent properties, and ease of functionalization and processing. However, existing photoswitchable fluorescent polymer materials still suffer from a limited variety of photochromic compounds and unadjustable fluorescence color change rates. This makes it difficult to create dynamic fluorescence patterns and makes them susceptible to duplication and counterfeiting, limiting their practical application in anti-counterfeiting. This present invention is therefore proposed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for using a light-switchable fluorescent polymer for dynamic fluorescent anti-counterfeiting. Three light-switchable fluorescent polymers for dynamic fluorescent anti-counterfeiting are prepared and applied to dynamic fluorescent anti-counterfeiting labels. The present invention utilizes a one-step free radical photopolymerization technology and combines three spiropyran monomers with different structures to prepare three light-switchable fluorescent polymers P1, P2, and P3 with different fluorescence color change rates. Further application research shows that these three light-switchable fluorescent polymers not only have multiple reversible fluorescence switching properties, but also exhibit significant differences in the fluorescence color change rates (red to green) of the three polymers after being irradiated by ultraviolet light and placed in the dark at room temperature. Utilizing this characteristic, P1, P2, and P3 are cut and spliced ​​together according to a designed shape to produce an anti-counterfeiting label that exhibits dynamic fluorescence color change characteristics after being irradiated by ultraviolet light and placed in the dark at room temperature. This method is simple, structurally stable, has good processability, is suitable for scale-up synthesis and practical application, and has broad application prospects in the fields of optical anti-counterfeiting and information encryption.

[0005] The present invention provides a method for applying a light-switchable fluorescent polymer to dynamic fluorescent anti-counterfeiting, comprising the following steps:

[0006] Step 1.1, preparation of photoswitchable fluorescent polymer P1: Methyl acrylate (MA), 1,6-hexanediol diacrylate (HDDA), 8-(4'-methacrylatephenyl)-1,3,5,7-tetramethylboron fluoride complexed dipyrromethene (BDPMA), (2-(3',3'-dimethyl-6-nitrospiro[benzopyran-2,2'-indoline]-1'-yl)ethyl-methacrylate (SPMA) and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator 819) were mixed and dissolved in a certain proportion and placed in a mold, and photopolymerized under visible light (460 nm) to obtain photoswitchable fluorescent polymer P1.

[0007] The structural formula of P1 is:

[0008] Among them, x:y:z:m=1:10~20:3000~6000:5~20.

[0009] Step 1.2, preparation of photoswitchable fluorescent polymer P2: Methyl acrylate (MA), 1,6-hexanediol diacrylate (HDDA), 8-(4'-methacrylatephenyl)-1,3,5,7-tetramethylboron fluoride complexed dipyrromethene (BDPMA), 2-(3',3',8-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate (SPAMA) and photoinitiator 819 were mixed and dissolved in a certain proportion and placed in a mold, and photopolymerized under visible light (460 nm) to obtain photoswitchable fluorescent polymer P2.

[0010] The structural formula of P2 is:

[0011] Among them, x:y:z:m=1:10~20:3000~6000:5~20.

[0012] Step 1.3, preparation of photoswitchable fluorescent polymer P3: Methyl acrylate (MA), 1,6-hexanediol diacrylate (HDDA), 8-(4'-methacrylatephenyl)-1,3,5,7-tetramethylboron fluoride complexed dipyrromethene (BDPMA), 2-(3',3',5-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate (SPBMA) and photoinitiator 819 were mixed and dissolved in a certain proportion and placed in a mold, and photopolymerized under visible light (460 nm) to obtain photoswitchable fluorescent polymer P3.

[0013] The structural formula of P3 is:

[0014] Among them, x:y:z:m=1:10~20:3000~6000:5~20.

[0015] In step 1.4, the optically switchable fluorescent polymers P1, P2, and P3 are cut and spliced ​​together according to the designed shape to produce an anti-counterfeiting label having a dynamic fluorescent color-changing feature after being irradiated with ultraviolet light and placed in the dark at room temperature. That is, the prepared anti-counterfeiting label has a dynamic fluorescent color-changing feature after being irradiated with ultraviolet light. This feature is utilized to apply it to dynamic fluorescent anti-counterfeiting.

[0016] In the above step 1.1, 8-(4'-methacrylate phenyl)-1,3,5,7-tetramethylboron fluoride complexed dipyrromethene (BDPMA) is prepared according to the prior art, and its structural formula is as follows:

[0017]

[0018] In the above step 1.1, (2-(3',3'-dimethyl-6-nitrospiro[benzopyran-2,2'-indoline]-1'-yl)ethyl-methacrylate (SPMA) prepared according to the prior art has the following structural formula:

[0019]

[0020] In the above step 1.1, the mass ratio of MA, HDDA, photoinitiator 819, BDPMA and SPMA is 1: 0.01-0.05: 0.001-0.01: 0.0001-0.001: 0.001-0.01.

[0021] In the above step 1.2, 2-(3',3',8-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate (SPAMA) has the following structural formula:

[0022]

[0023] The synthesis steps are:

[0024]

[0025] 1-(2-Hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium and 2-hydroxy-3-methyl-5-nitrobenzaldehyde, prepared according to prior art, were added to an ethanol solution containing piperidine. The mixture was stirred at 80°C under nitrogen for 12 hours. After the reaction, the solution was dried by spin drying. The dried solid was then added to a dichloromethane solution containing methacrylic acid, 4-dimethylaminopyridine, and N,N'-diisopropylcarbodiimide. The reaction was continued at room temperature for 12 hours. The organic layer was washed with water and dried over anhydrous magnesium sulfate. The organic layer was filtered and concentrated to obtain a crude product. This was further purified by column chromatography to obtain a solid powder, namely SPAMA. Among them, the mass ratio of 1-(2-hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium, 2-hydroxy-3-methyl-5-nitrobenzaldehyde, piperidine, ethanol, methacrylic acid, 4-dimethylaminopyridine, N,N'-diisopropylcarbodiimide, and dichloromethane is: 1:1.2~1.5:0.1~0.4:10~20:1~6:1~4:5~20:20~30.

[0026] In the above step 1.2, the mass ratio of MA, HDDA, photoinitiator 819, BDPMA and SPAMA is 1: 0.01-0.05: 0.001-0.01: 0.0001-0.001: 0.001-0.01.

[0027] In the above step 1.3, 2-(3',3',5-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate (SPBMA) has the following structural formula:

[0028]

[0029] The synthesis steps are:

[0030]

[0031] 1-(2-Hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium and 6-hydroxy-2-methyl-3-nitrobenzaldehyde, prepared according to prior art, were added to an ethanol solution containing piperidine. The mixture was stirred at 80°C under nitrogen for 12 hours. After the reaction, the solution was dried by spin drying. The dried solid was then added to a dichloromethane solution containing methacrylic acid, 4-dimethylaminopyridine, and N,N'-diisopropylcarbodiimide. The reaction was continued at room temperature for 12 hours. The organic layer was washed with water and dried over anhydrous magnesium sulfate. The organic layer was filtered and concentrated to obtain a crude product. The product was further purified by column chromatography to obtain a solid powder, namely SPAMA. Among them, the mass ratio of 1-(2-hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium, 6-hydroxy-2-methyl-3-nitrobenzaldehyde, piperidine, ethanol, methacrylic acid, 4-dimethylaminopyridine, N,N'-diisopropylcarbodiimide, and dichloromethane is: 1:1.2~1.5:0.1~0.4:10~20:1~4:1~5:5~20:20~30.

[0032] In the above step 1.3, the mass ratio of MA, HDDA, photoinitiator 819, BDPMA and SPBMA is 1: 0.01-0.05: 0.001-0.01: 0.0001-0.001: 0.001-0.01.

[0033] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0034] (1) The three photoswitchable fluorescent polymers P1, P2, and P3 synthesized in the present invention exhibit red fluorescence that gradually and spontaneously transforms into green fluorescence when exposed to ultraviolet light and placed in darkness at room temperature. Due to the structural differences in the spiropyrans (SPMA, SPAMA, and SPBMA) bound to the three polymers, the three photoswitchable fluorescent polymers exhibit distinct differences in their fluorescence color change (from red to green). This difference can be exploited to prepare anti-counterfeiting labels with dynamic fluorescence color change characteristics.

[0035] (2) The present invention uses dynamic fluorescent color change to achieve anti-counterfeiting. Compared with conventional static anti-counterfeiting technology, its advantage is that this dynamic change process can reveal more information and greatly increases the difficulty of counterfeiting. At the same time, the means of reading the information do not increase. In other words, it is easy to read while increasing the difficulty of counterfeiting as much as possible.

[0036] (3) The optically switchable fluorescent polymer prepared in the present invention has excellent elasticity, certain adhesion and plasticity, and can be processed and spliced ​​to prepare anti-counterfeiting label patterns of different shapes and compositions, which is conducive to adapting to different actual anti-counterfeiting application scenarios.

[0037] (4) The optically switchable fluorescent polymer produced by the present invention is simple and fast to prepare, does not require the addition of solvents, and does not require post-processing, which has great advantages in scale-up synthesis and actual production applications.

[0038] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are part of this application and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an undue limitation of the present invention. Obviously, the drawings described below are only some embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without inventive effort. In the accompanying drawings:

[0040] Figure 1 This is the H NMR spectrum of the photochromic spiropyran molecule SPAMA;

[0041] Figure 2 This is the H NMR spectrum of the photochromic spiropyran molecule SPBMA;

[0042] Figure 3 The fluorescence changes of the prepared P1 photoswitchable fluorescent polymer at room temperature in the dark and after irradiation with ultraviolet light;

[0043] Figure 4 The fluorescence changes of the prepared P2 photoswitchable fluorescent polymer at room temperature in the dark and after irradiation with ultraviolet light;

[0044] Figure 5 The fluorescence changes of the prepared P3 photoswitchable fluorescent polymer at room temperature in the dark and after irradiation with ultraviolet light;

[0045] Figure 6 Normalized fluorescence spectra of P1, P2, and P3 photoswitchable fluorescent polymers at 515 nm in the dark at room temperature after irradiation with UV light;

[0046] Figure 7 The fluorescence photographs of the P1, P2, and P3 light-switch fluorescent polymers after irradiation with UV light in the dark at room temperature are shown;

[0047] Figure 8 Photographs of the dynamic fluorescence changes of anti-counterfeiting labels made of P1, P2, and P3 light-switch fluorescent polymers after being irradiated with ultraviolet light and placed in the dark at room temperature.

[0048] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in combination with the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0050] Example 1:

[0051] (1) Synthesis of 2-(3',3',8-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate (SPAMA):

[0052]

[0053] 1-(2-Hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium (1 g) and 2-hydroxy-3-methyl-5-nitrobenzaldehyde (1.2 g) were added to a solution of piperidine (0.1 g) in ethanol (20 g). The mixture was stirred at 80°C under nitrogen for 12 hours. After the reaction, the solution was dried by spin drying. The dried solid was added to a solution of methacrylic acid (3 g), 4-dimethylaminopyridine (1 g), and N,N'-diisopropylcarbodiimide (5 g) in dichloromethane (30 g). The reaction was continued at room temperature for 12 hours. The organic layer was washed with water and dried over anhydrous magnesium sulfate. The organic layer was filtered and concentrated to obtain a crude product. The product was further purified by column chromatography to obtain a solid powder, namely, the product SPAMA (1.06 g).

[0054] (2) Synthesis of 2-(3',3',5-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate (SPBMA):

[0055]

[0056] 1-(2-Hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium (1 g) and 6-hydroxy-2-methyl-3-nitrobenzaldehyde (1.2 g) were added to a solution of piperidine (0.1 g) in ethanol (20 g). The mixture was stirred at 80°C under nitrogen for 12 hours. After the reaction, the solution was dried by spin drying. The dried solid was then added to a solution of methacrylic acid (3 g), 4-dimethylaminopyridine (1 g), and N,N'-diisopropylcarbodiimide (5 g) in dichloromethane (30 g). The reaction was continued at room temperature for 12 hours. The organic layer was washed with water and dried over anhydrous magnesium sulfate. The organic layer was filtered and concentrated to obtain a crude product. The product, SPBMA (0.85 g), was further purified by column chromatography to obtain a solid powder.

[0057] Example 2: Preparation of optically switchable fluorescent polymers P1, P2, and P3. The specific steps are as follows:

[0058] (1) Methyl acrylate (10 g), 1,6-hexanediol diacrylate (0.1 g), photoinitiator 819 (0.01 g), BDPMA (0.001 g) and 0.05 g of SPMA were mixed and dissolved, injected and placed in a sealed reaction cell consisting of glass plates with a spacing of 1 mm. Polymerization was carried out under visible light (460 nm, 40 mW / min) for 10 minutes to obtain a photoswitchable fluorescent polymer P1.

[0059] (2) Methyl acrylate (10 g), 1,6-hexanediol diacrylate (0.1 g), photoinitiator 819 (0.01 g), BDPMA (0.001 g) and 0.05 g of SPAMA were mixed and dissolved, injected and placed in a sealed reaction cell consisting of glass plates with a spacing of 1 mm. Polymerization was carried out under visible light (460 nm, 40 mW / min) for 10 minutes to obtain a photoswitchable fluorescent polymer P2.

[0060] (3) Methyl acrylate (10 g), 1,6-hexanediol diacrylate (0.1 g), photoinitiator 819 (0.01 g), BDPMA (0.001 g) and 0.05 g of SPBMA were mixed and dissolved, injected and placed in a sealed reaction cell consisting of glass plates with a spacing of 1 mm. Polymerization was carried out under visible light (460 nm, 40 mW / min) for 10 minutes to obtain a photoswitchable fluorescent polymer P3.

[0061] Example 3: Fluorescence changes of photoswitchable fluorescent polymers P1, P2, and P3 at room temperature in darkness and after irradiation with ultraviolet light.

[0062] Figure 1 is the H NMR spectrum of the photochromic spiropyran molecule SPAMA prepared in Example 1(1), Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of the photochromic spiropyran molecule SPBMA prepared in Example 1(2). Figure 3 The fluorescence spectra of the P1 photoswitchable fluorescent polymer prepared in Example 2(1) in the range of 490 to 800 nm at room temperature in darkness and after irradiation with ultraviolet light. Figure 4 The fluorescence spectra of the P2 photoswitch fluorescent polymer prepared in Example 2(2) in the range of 490 to 800 nm at room temperature in darkness and after irradiation with ultraviolet light. Figure 5 The fluorescence spectra of the P3 photoswitchable fluorescent polymer prepared in Example 2(3) in the range of 490 to 800 nm at room temperature in darkness and after irradiation with ultraviolet light. Figure 3 , Figure 4 and Figure 5It can be seen that the P1, P2, and P3 photoswitchable fluorescent polymers have an obvious green fluorescence peak of BDPMA at 515 nm in a dark environment at room temperature. After irradiation with ultraviolet light, due to the FRET effect, the green fluorescence peak at 515 nm decreases significantly, and the red fluorescence peak of the photochromic spiropyran molecules (SPMA, SPAMA, SPBMA) at 650 to 700 nm is significantly enhanced. At the same time, the P1, P2, and P3 photoswitchable fluorescent polymers have very obvious fluorescence color changes (green to red) before and after irradiation with ultraviolet light.

[0063] Example 4: Normalized fluorescence spectra of the photoswitchable fluorescent polymers P1, P2, and P3 at 515 nm in the dark at room temperature after irradiation with UV light.

[0064] Figure 6 The graph shows the change in normalized fluorescence intensity at 515 nm of the P1, P2, and P3 light-switchable fluorescent polymers prepared in Example 2 after being irradiated with UV light and placed in the dark at room temperature. Figure 6 It can be seen that the fluorescence intensity of the P1 photoswitchable fluorescent polymer at 515 nanometers will not return to its initial fluorescence intensity until it has been placed in darkness at room temperature for 170 minutes. The fluorescence intensity of the P2 photoswitchable fluorescent polymer at 515 nanometers will return to its initial fluorescence intensity after it has been placed in darkness at room temperature for 120 minutes. The fluorescence intensity of the P3 photoswitchable fluorescent polymer at 515 nanometers will return to its initial fluorescence intensity after it has been placed in darkness at room temperature for 20 minutes. The results show that after irradiation with UV light and placed in darkness at room temperature, the fluorescence of the P3 photoswitchable fluorescent polymer at 515 nanometers recovers the fastest, followed by P2, and the slowest for P1. Based on this, they can be combined to achieve dynamic fluorescent anti-counterfeiting.

[0065] Example 5: Photographs of fluorescence changes of P1, P2, and P3 photoswitchable fluorescent polymers in the dark at room temperature after irradiation with UV light

[0066] Figure 7 The following is a photograph of the fluorescence changes of the P1, P2, and P3 light-switch fluorescent polymers prepared in Example 2 after irradiation with ultraviolet light in the dark at room temperature. Figure 7 It can be seen that after the P1, P2, and P3 photoswitch fluorescent polymers are irradiated with ultraviolet light and placed in the dark at room temperature, the P3 photoswitch fluorescent polymer changes from red fluorescence to green fluorescence the fastest, followed by P2, and P1 the slowest. There are obvious differences in the speed of the change in fluorescence color.

[0067] Example 6: Anti-counterfeiting labels made of P1, P2, and P3 light-switch fluorescent polymers.

[0068] like Figure 8As shown, a flower anti-counterfeiting label consisting of leaves (P1), stems (P2) and petals (P3) was prepared by using the P1, P2, and P3 light-switch fluorescent polymers prepared in Example 2. The flower anti-counterfeiting label is green fluorescent in the initial state, but when the flower is irradiated by ultraviolet light, the entire anti-counterfeiting label will show red fluorescence. After the ultraviolet light is removed and the flower is placed in the dark at room temperature for 20 minutes, the fluorescence of the petals will first change from red to green. After being placed for 120 minutes, the fluorescent color of the stem will also change from red to green. After being placed for 170 minutes, the fluorescent color of the entire label will return to the initial green fluorescence. This shows that the anti-counterfeiting label we prepared has a good dynamic fluorescent anti-counterfeiting effect.

[0069] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with this patent can make slight changes or modifications to equivalent embodiments using the above technical content without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.

Claims

1. A method for using a light-switchable fluorescent polymer for dynamic fluorescent anti-counterfeiting, characterized in that: The following steps are involved: Step 1.1, Preparation of photoswitchable fluorescent polymer P1: Methyl acrylate MA, 1,6-hexanediol diacrylate HDDA, 8-(4'-methacrylatephenyl)-1,3,5,7-tetramethylboron fluoride complex dipyrromethene BDPMA, (2-(3',3'-dimethyl-6-nitrospiro[benzopyran-2,2'-indoline]-1'-yl)ethyl-methacrylate SPMA, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were mixed and dissolved in a certain proportion and placed in a mold. The mixture was then photopolymerized under 460 nm visible light to obtain photoswitchable fluorescent polymer P1, the structural formula of which is as follows: Wherein, x:y:z:m=1:10~20:3000~6000:5~20; Step 1.2, Preparation of photoswitchable fluorescent polymer P2: Methyl acrylate MA, 1,6-hexanediol diacrylate HDDA, 8-(4'-methacrylatephenyl)-1,3,5,7-tetramethylboron fluoride complex dipyrromethene BDPMA, 2-(3',3',8-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate SPAMA, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were mixed and dissolved in a certain proportion and placed in a mold. The mixture was then photopolymerized under 460 nm visible light to obtain photoswitchable fluorescent polymer P2, the structural formula of which is as follows: Wherein, x:y:z:m=1:10~20:3000~6000:5~20; Step 1.3, Preparation of photoswitchable fluorescent polymer P3: Methyl acrylate MA, 1,6-hexanediol diacrylate HDDA, 8-(4'-methacrylatephenyl)-1,3,5,7-tetramethylboron fluoride complex dipyrromethene BDPMA, 2-(3',3',5-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate SPBMA, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were mixed and dissolved in a certain proportion in a mold, and photopolymerized under 460 nm visible light to obtain photoswitchable fluorescent polymer P3, whose structural formula is as follows: Wherein, x:y:z:m=1:10~20:3000~6000:5~20; In step 1.4, the light-switchable fluorescent polymers P1, P2, and P3 are cut and spliced ​​together according to the designed shape to produce an anti-counterfeiting label having a dynamic fluorescent color-changing feature after being irradiated with ultraviolet light and placed in the dark at room temperature.

2. The method for using a photoswitchable fluorescent polymer for dynamic fluorescent anti-counterfeiting according to claim 1, characterized in that: In the step 1.1, the mass ratio of methyl acrylate MA, 1,6-hexanediol diacrylate HDDA, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 8-(4'-methacrylate phenyl)-1,3,5,7-tetramethylboron fluoride complex dipyrromethene BDPMA, and (2-(3',3'-dimethyl-6-nitrospiro[benzopyran-2,2'-indoline]-1'-yl)ethyl-methacrylate SPMA is 1: 0.01-0.05: 0.001-0.01: 0.0001-0.001: 0.001-0.

01.

3. The method for using a photoswitchable fluorescent polymer for dynamic fluorescent anti-counterfeiting according to claim 1, characterized in that: The photochromic spiropyran molecule SPAMA in step 1.2 has the following structural formula:

4. The method for using a photoswitchable fluorescent polymer for dynamic fluorescent anti-counterfeiting according to claim 1 or 3, characterized in that: The synthesis steps of the spiropyran molecule SPAMA in step 1.2 are as follows: 1-(2-hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium and 2-hydroxy-3-methyl-5-nitrobenzaldehyde prepared according to the prior art are added to an ethanol solution containing piperidine, and stirred at 80° C. for 12 hours under nitrogen protection. After the reaction, the solution is dried by spin drying, and the dried solid is added to a dichloromethane solution containing methacrylic acid, 4-dimethylaminopyridine and N,N'-diisopropylcarbodiimide, and reacted at room temperature for 12 hours. The organic layer is washed with water and dried over anhydrous magnesium sulfate; the organic layer is filtered and concentrated to obtain a crude product, which is further purified by column to obtain a solid powder, namely SPAMA; Among them, the mass ratio of 1-(2-hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium, 2-hydroxy-3-methyl-5-nitrobenzaldehyde, piperidine, ethanol, methacrylic acid, 4-dimethylaminopyridine, N,N'-diisopropylcarbodiimide, and dichloromethane is: 1:1.2~1.5:0.1~0.4:10~20:1~6:1~4:5~20:20~30.

5. The method for using a photoswitchable fluorescent polymer for dynamic fluorescent anti-counterfeiting according to claim 1, characterized in that: In the step 1.2, the mass ratio of methyl acrylate MA, 1,6-hexanediol diacrylate HDDA, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 8-(4'-methacrylatephenyl)-1,3,5,7-tetramethylboron fluoride complex dipyrromethene BDPMA, and 2-(3',3',8-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate SPAMA is 1: 0.01-0.05: 0.001-0.01: 0.0001-0.001: 0.001-0.

01.

6. The method for using a photoswitchable fluorescent polymer for dynamic fluorescent anti-counterfeiting according to claim 1, characterized in that: The photochromic spiropyran molecule SPBMA in step 1.3 has the following structural formula:

7. The method for using a photoswitchable fluorescent polymer for dynamic fluorescent anti-counterfeiting according to claim 1 or 6, characterized in that: The synthesis steps of the spiropyran molecule SPBMA in step 1.3 are as follows: 1-(2-Hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium and 6-hydroxy-2-methyl-3-nitrobenzaldehyde prepared according to the prior art are added to an ethanol solution containing piperidine, and stirred at 80° C. for 12 hours under nitrogen protection. After the reaction, the solution is dried by spin drying, and the dried solid is added to a dichloromethane solution containing methacrylic acid, 4-dimethylaminopyridine and N,N'-diisopropylcarbodiimide, and the reaction is carried out at room temperature for 12 hours. The organic layer is washed with water and dried over anhydrous magnesium sulfate; the organic layer is filtered and concentrated to obtain a crude product, which is further purified by column to obtain a solid powder, namely SPAMA; Among them, the mass ratio of 1-(2-hydroxyethyl)-2,3,3-trimethyl-3H-indol-1-ium, 6-hydroxy-2-methyl-3-nitrobenzaldehyde, piperidine, ethanol, methacrylic acid, 4-dimethylaminopyridine, N,N'-diisopropylcarbodiimide, and dichloromethane is: 1:1.2~1.5:0.1~0.4:10~20:1~4:1~5:5~20:20~30.

8. The method for using a photoswitchable fluorescent polymer for dynamic fluorescent anti-counterfeiting according to claim 1, characterized in that: In the step 1.3, the mass ratio of methyl acrylate MA, 1,6-hexanediol diacrylate HDDA, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 8-(4'-methacrylate phenyl)-1,3,5,7-tetramethylboron fluoride complex dipyrromethene BDPMA, and 2-(3',3',5-trimethyl-6-nitrospiro[benzopyran-2,2'-dihydroindole]-1'-yl)ethyl methacrylate SPBMA is 1: 0.01-0.05: 0.001-0.01: 0.0001-0.001: 0.001-0.01.

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