Preparation method of anti-counterfeiting label and anti-counterfeiting label

Abstract

The application provides a preparation method of a security label and the security label, and the preparation method comprises: sequentially forming a first security structure and a second security structure in a laminated arrangement on a surface of a substrate, forming the first security structure comprises forming a perovskite film on the surface of the substrate, the perovskite film can be irradiated by a first light beam to present a first preset pattern, and forming the second security structure comprises forming a structural color film on a side of the perovskite film away from the substrate, the structural color film can be irradiated by a second light beam to present a second preset pattern. Wherein, the structural color film is formed by irradiation light sequentially irradiating through a first mask plate and a second mask plate, a mask pattern of the first mask plate is the same as the second preset pattern, and the second mask plate is a first-pitch grating, so that the structural color film presents a microarray structure, based on the microarray structure, the structural color pattern and the fluorescent pattern can be selectively hidden and displayed, and then information encryption of the security structure is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of anti-counterfeiting technology, in particular to a preparation method of an anti-counterfeiting label and the anti-counterfeiting label. BACKGROUND

[0002] Information encryption and anti-counterfeiting has been a hot issue of long-term concern in society, and related research involves multidisciplinary intersection, such as material science, information technology, optics, chemistry, etc., and its continuous development also promotes the scientific and technological progress and innovation in related fields.

[0003] At present, compared with traditional anti-counterfeiting technologies of single mode such as structural color, fluorescence or circularly polarized fluorescence, dual-mode or even multi-mode anti-counterfeiting technology can greatly increase the information storage capacity, and further improve the information security and anti-counterfeiting level. Therefore, for those skilled in the art, dual-mode and multi-mode anti-counterfeiting technology has become a key topic. SUMMARY

[0004] Therefore, the present application provides a preparation method of a label and an anti-counterfeiting label, and the scheme is as follows:

[0005] A preparation method of an anti-counterfeiting label, comprising:

[0006] providing a substrate;

[0007] forming a first anti-counterfeiting structure and a second anti-counterfeiting structure arranged in sequence on the surface of the substrate;

[0008] the forming of the first anti-counterfeiting structure comprises:

[0009] forming a perovskite film on the surface of the substrate, the shape of the perovskite film being a first preset pattern, and the perovskite film being capable of being irradiated by a first light beam to present the first preset pattern;

[0010] the forming of the second anti-counterfeiting structure comprises:

[0011] forming a structural color film on the side of the perovskite film away from the substrate, the shape of the structural color film being a second preset pattern, and the structural color film being capable of being irradiated by a second light beam to present the second preset pattern;

[0012] wherein the forming of the structural color film on the side of the perovskite film away from the substrate comprises:

[0013] dropping a diacetylene liquid on the side of the perovskite film away from the substrate to form a diacetylene layer, the diacetylene liquid having diacetylene monomers;

[0014] placing a first mask plate and a second mask plate in sequence above the surface of the substrate, and irradiating the diacetylene layer through the first mask plate and the second mask plate in sequence to form the structural color film;

[0015] acetonitrile is added to the structural color film, and the structural color film is treated with acetonitrile;

[0016] The first mask plate has the same pattern as the second preset pattern, and the second mask plate is a first-pitch grating.

[0017] Optionally, forming the structural color film on the side of the perovskite film away from the substrate further includes:

[0018] The irradiation light irradiates the diacetylene layer through the back surface of the substrate to form the structural color film.

[0019] The back surface of the substrate is opposite to the surface of the substrate.

[0020] Optionally, the second preset pattern includes a first sub-pattern, the first sub-pattern includes a first part and a second part arranged along a first direction, the second mask plate includes a first mask area, the first direction is parallel to a plane in which the structural color film is located and parallel to a periodic direction of the first mask area, and the irradiation light irradiates the diacetylene layer through the first mask plate and the second mask plate in sequence to form the structural color film, including:

[0021] The irradiation light irradiates the diacetylene layer through the first mask plate and the first mask area in sequence.

[0022] Then, the irradiation light irradiates the second part through the back surface of the substrate to form the structural color film.

[0023] When the incident direction of the second light beam is perpendicular to the first direction, the structural color film can be irradiated by the second light beam to present the first sub-pattern, and when the incident direction of the second light beam is perpendicular to the first direction and the structural color film is treated with acetonitrile, the structural color film can be irradiated by the second light beam to present a first part of the first sub-pattern.

[0024] Optionally, the second preset pattern further includes a second sub-pattern, the first sub-pattern and the second sub-pattern are arranged along a second direction, the second sub-pattern includes a third part and a fourth part arranged along the first direction, the second mask plate includes a second mask area, the second direction is parallel to a plane in which the structural color film is located and parallel to a periodic direction of the second mask area, and the second direction is perpendicular to the first direction, and the irradiation light irradiates the diacetylene layer through the first mask plate and the second mask plate in sequence to form the structural color film, including:

[0025] After the irradiation light passes through the first mask plate, the irradiation light irradiates the diacetylene layer through the first mask area and the second mask area.

[0026] Afterwards, the irradiation light irradiates the second part and the fourth part through the back surface of the substrate, to form the structural color film;

[0027] Wherein, if the incident direction of the second light beam is parallel to the first direction and perpendicular to the second direction, the structural color film can be irradiated by the second light beam to present the second sub-pattern; if the incident direction of the second light beam is perpendicular to the second direction and the structural color film is treated by acetonitrile, the structural color film can be irradiated by the second light beam to present the third part of the second sub-pattern.

[0028] Optionally, the forming the structural color film on the side of the perovskite film away from the substrate further comprises:

[0029] placing a third mask plate above the surface of the substrate, the third mask plate being located between the first mask plate and the second mask plate, and irradiation light sequentially passes through the first mask plate, the third mask plate and the second mask plate to irradiate the diacetylene layer, to form the structural color film;

[0030] The third mask plate is a grating with a second pitch, and the second pitch is greater than the first pitch.

[0031] Optionally, the forming the structural color film on the side of the perovskite film away from the substrate further comprises:

[0032] placing a fourth mask plate on the back surface of the substrate, and irradiation light sequentially passes through the fourth mask plate and the substrate to irradiate the diacetylene layer, to form the structural color film;

[0033] Wherein, the fourth mask plate is a grating with a third pitch, and the third pitch is equal to the second pitch.

[0034] Optionally, the second preset pattern comprises a third sub-pattern and a fourth sub-pattern, the first mask plate comprises a first sub-mask plate and a second sub-mask plate, the pattern of the first sub-mask plate is the same as the third sub-pattern, and the pattern of the second sub-mask plate is the same as the fourth sub-pattern; the sequentially placing the first mask plate and the second mask plate above the surface of the substrate, and irradiation light sequentially passes through the first mask plate and the second mask plate to irradiate the diacetylene layer, to form the structural color film comprises:

[0035] sequentially placing the first sub-mask plate and the second mask plate above the surface of the substrate, and irradiation light sequentially passes through the first sub-mask plate and the second mask plate to irradiate the diacetylene layer;

[0036] rotating the second mask plate by 90° along a third direction, placing a second sub-mask plate above the second mask plate, and irradiating the diacetylene layer with light through the second sub-mask plate and the second mask plate in sequence to form the structural color film, wherein the third direction is parallel to the mounting surface of the second mask plate;

[0037] If the incident direction of the second light beam is perpendicular to a fourth direction, the fourth direction is parallel to the periodic direction of the second mask plate before rotation, and the structural color film can be irradiated by the second light beam to present the third sub-pattern; if the incident direction of the second light beam is parallel to the fourth direction, the structural color film can be irradiated by the second light beam to present the fourth sub-pattern.

[0038] Optionally, the forming of the perovskite film on the surface of the substrate comprises:

[0039] adding a CsPbX3 perovskite nanocrystal n-hexane solution into the silicone elastomer to form a perovskite mixture;

[0040] coating the perovskite mixture on the surface of the substrate in the first preset pattern to form the perovskite film;

[0041] wherein the perovskite film is a CsPbX3 perovskite film, and X is Br, Cl or I.

[0042] Optionally, the forming of the first anti-counterfeiting structure further comprises:

[0043] forming a silver nanowire layer on the side of the perovskite film away from the substrate;

[0044] the forming of the silver nanowire layer on the side of the perovskite film away from the substrate comprises:

[0045] forming a first silver nanowire layer on the side of the perovskite film away from the substrate, and the orientation of the first silver nanowire layer is a first angle;

[0046] forming a second silver nanowire layer on the side of the first silver nanowire layer away from the substrate, and the orientation of the second silver nanowire layer is a second angle;

[0047] wherein the first angle and the second angle are different.

[0048] Optionally, the first angle is 45°, and the second angle is -45°.

[0049] Optionally, the perovskite film is a CsPbBr3 perovskite film, and the first preset pattern comprises a fifth sub-pattern and a sixth sub-pattern.

[0050] If the perovskite film is observed by using a left-handed circular polarizer, the fifth sub-pattern appears blue; if the perovskite film is observed by using a right-handed circular polarizer, the sixth sub-pattern appears red.

[0051] If the first security structure is treated by using HCl, the fluorescence wavelength of the perovskite film is blue-shifted; if the first security structure is treated by using HI, the fluorescence wavelength of the perovskite film is red-shifted.

[0052] A security label, characterized in that it comprises:

[0053] a substrate;

[0054] a first security structure and a second security structure arranged in sequence on the surface of the substrate;

[0055] The first security structure comprises a perovskite film on the surface of the substrate, the shape of the perovskite film is a first preset pattern, and the perovskite film can be irradiated by a first light beam to appear the first preset pattern; the second security structure comprises a structural color film formed on the side of the perovskite film away from the substrate, the shape of the structural color film is a second preset pattern, and the structural color film can be irradiated by a second light beam to appear the second preset pattern.

[0056] The structural color film is irradiated by light in sequence through a first mask plate and a second mask plate, the pattern of the first mask plate is the same as the second preset pattern, and the second mask plate is a first-pitch grating.

[0057] Optionally, the first security structure further comprises:

[0058] a silver nanowire layer formed on the side of the perovskite film away from the substrate, the silver nanowire layer comprises a first silver nanowire layer formed on the side of the perovskite film away from the substrate, and a second silver nanowire layer formed on the side of the first silver nanowire layer away from the substrate;

[0059] The orientation of the first silver nanowire layer is a first angle, the orientation of the second silver nanowire layer is a second angle, and the first angle and the second angle are different.

[0060] Optionally, the first angle is 45°, and the second angle is -45°.

[0061] Compared with the prior art, the technical scheme of the present application has the following advantages:

[0062] The preparation method comprises: sequentially forming a first anti-counterfeiting structure and a second anti-counterfeiting structure arranged in a stack on a surface of a substrate, forming the first anti-counterfeiting structure comprises forming a perovskite film on the surface of the substrate, the perovskite film can be irradiated by a first light beam to present a first preset pattern, and forming the second anti-counterfeiting structure comprises forming a structural color film on a side of the perovskite film away from the substrate, the structural color film can be irradiated by a second light beam to present a second preset pattern. Forming the structural color film on the side of the perovskite film away from the substrate comprises forming a diacetylene layer on the side of the perovskite film away from the substrate, irradiating the diacetylene layer by the light beam sequentially through a first mask plate and a second mask plate to form the structural color film, and treating the structural color film by using acetonitrile. The pattern of the first mask plate is the same as the second preset pattern, and the second mask plate is a grating with a first pitch.

[0063] As known from the above, the structural color film is obtained by irradiating the diacetylene layer by the light beam sequentially through the first mask plate and the second mask plate, and the second mask plate is a grating, so the structural color film presents a microarray structure. Due to the diffraction effect and scattering effect of the microarray structure, the fluorescence intensity of the perovskite film transmitted through the structural color film is affected by the diffraction effect and scattering effect of the structural color film, and the diffraction effect and scattering effect of the structural color film are related to the depth of the array structure, so for the anti-counterfeiting label prepared by the preparation method provided in the application, the display of the pattern of the perovskite film can be controlled by changing the depth of the array structure of the structural color film, and the pattern of the perovskite film can be selectively hidden or displayed. In addition, the depth of the microarray structure of the structural color film can also affect the display and hiding of the pattern of the structural color film, so the display and hiding of the pattern of the structural color film can also be controlled by changing the depth of the array structure of the structural color film. As can be seen, the anti-counterfeiting label prepared by the preparation method provided in the application can selectively hide and display the encrypted information, which is helpful to realize selective decryption and decoding of information, and further helps to realize higher information encryption and decoding, and provides a feasible scheme for high-level anti-counterfeiting and information encryption, and has important application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0064] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating labor on the basis of the provided drawings.

[0065] The structure, proportion, size, etc. shown in the drawings of the specification are only used to cooperate with the content disclosed in the specification, to be understood and read by those skilled in the art, and do not have technical significance to define the limitations of the application. Any modification of the structure, change of the proportion relationship or adjustment of the size, which does not affect the effect and purpose that can be achieved by the application, should still fall within the scope of the disclosed technical content.

[0066] Figure 1 A flow chart of a preparation method of a security label provided by the application;

[0067] Figure 2 A structural diagram of a security label provided by the application;

[0068] Figure 3 A flow chart of another preparation method of a security label provided by the application;

[0069] Figure 4 A flow chart of another preparation method of a security label provided by the application;

[0070] Figures 5-14 Light emission schematic diagrams of the security label prepared by the application in different application scenarios. DETAILED DESCRIPTION

[0071] The embodiments in the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a regional embodiment of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the application.

[0072] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the application will be further described in detail below with reference to the drawings and specific embodiments.

[0073] As described in the background section, dual-mode and multi-mode security technology plays an important role in improving information security and security level, and therefore has become the research focus of those skilled in the art.

[0074] The current limitation of dual-mode or multi-mode is that there is mutual interference between different optical modes, and the security pattern is not tunable, which is not conducive to the development of multi-mode security technology. The above-mentioned dual-mode refers to the combination of different optical modes, such as the combination of structural color and fluorescence, and multi-mode refers to the combination of more optical modes.

[0075] Specifically, for traditional dual-mode and multi-mode, different optical mode patterns (such as structural color and fluorescence information) in the same area tend to be strongly interfered with each other during manufacturing and use, especially during dynamic adjustment. Moreover, traditional dual-mode and multi-mode cannot independently modulate structural color and fluorescence (CPL) information.

[0076] Based on the above, as Figure 1 shown, Figure 1 A flowchart of a preparation method of a security label provided by the present application, the preparation method comprising:

[0077] S1: providing a substrate 100, as Figure 2 shown, Figure 2 A structural schematic diagram of the security label prepared by the above preparation method. It should be noted that the substrate 100 can be a glass sheet, a quartz sheet, and a flexible substrate such as PVA, PET, etc.

[0078] S2: sequentially forming a first security structure 200 and a second security structure 300 arranged in a stack on the surface of the substrate 100, specifically, the first security structure 200 is located on the surface of the substrate 100, and the second security structure 300 is located on the side of the first security structure 200 away from the surface of the substrate 100.

[0079] For the above step S2, as Figure 3 shown, Figure 3 A flowchart of a preparation method of a security label provided by the present application, forming the first security structure 200 comprises:

[0080] S21: forming a perovskite film 210 on the surface of the substrate 100, the shape of the perovskite film 210 being a first preset pattern, and the perovskite film 210 being capable of being irradiated by a first light beam to present the first preset pattern, specifically, the perovskite film 210 can be excited by the first light beam to emit fluorescence, and the first preset pattern can be observed when the perovskite film 210 is excited to emit light by the first light beam.

[0081] Forming the second security structure 300 comprises:

[0082] S22: forming a structural color film 310 on the side of the perovskite film 210 away from the substrate 100, the shape of the structural color film 310 being a second preset pattern, and the structural color film 310 being capable of being irradiated by a second light beam to present the second preset pattern, specifically, the structural color film 310 can be irradiated by the second light beam to produce color, and the second preset pattern can be observed when the structural color film 310 is irradiated by the second light beam to produce color.

[0083] Wherein, for step S22, as Figure 4 shown, Figure 4A flowchart of a preparation method of a security label provided in the present application, forming a structural color film 310 on the side of the perovskite film 210 away from the substrate 100 includes:

[0084] S221: Drop diacetylene liquid on the side of the perovskite film 210 away from the substrate 100, to form a diacetylene layer, the diacetylene liquid containing diacetylene monomers. It should be noted that the diacetylene liquid specifically refers to a liquid mixed from diacetylene monomers and a photoinitiator, and the compound structure of the diacetylene monomers can be:

[0085]

[0086] S222: Place the first mask plate and the second mask plate successively above the surface of the substrate 100, and irradiate the diacetylene layer with the irradiation light successively through the first mask plate and the second mask plate to form the structural color film 310. It should be noted that the irradiation light can be violet light, but the present application does not limit this, which is determined according to the situation.

[0087] S223: Drop acetonitrile into the structural color film 310, and use acetonitrile to treat the structural color film 310, specifically drop acetonitrile into the structural color film 310, and whether to remove the acetonitrile can be selected according to actual needs. It should be noted that when acetonitrile is dropped into the structural color film 310, acetonitrile can also be used as an eluent to remove unpolymerized diacetylene monomers.

[0088] The pattern of the first mask plate is the same as the second preset pattern, and the second mask plate is a grating with a first pitch. It should be noted that the first pitch of the second mask plate, i.e. the pitch of the grating mask plate, is the distance between the grating slits, and the same explanation applies to the pitch of the grating mask plate in the subsequent description.

[0089] As known from the above, the structural color film 310 is obtained by irradiating the diacetylene layer with irradiation light through the first mask plate and the second mask plate in turn, and the second mask plate is a grating, so the structural color film 310 has a microarray structure. Due to the diffraction effect and scattering effect of the microarray structure, when the perovskite film 210 is excited to emit light, the fluorescence intensity of the perovskite film 210 transmitted through the structural color film 310 will be affected by the diffraction effect and scattering effect. The stronger the diffraction effect and scattering effect, the lower the fluorescence intensity after the structural color film 310. Conversely, the fluorescence intensity is stronger. The diffraction effect and scattering effect of the structural color film 310 are related to the depth of the array structure, so for the anti-counterfeiting label prepared by the preparation method provided in the present application, the pattern display of the perovskite film 210 can be controlled by changing the depth of the array structure of the structural color film 310. Specifically, the pattern display of the perovskite film 210 can be controlled by changing the depth of the array structure of the structural color film 310, and the pattern of the perovskite film 210 can be selectively hidden or displayed. At the same time, the depth of the microarray structure of the structural color film 310 can also affect the pattern display and hiding of the structural color film 310, that is, the pattern display and hiding of the structural color film 310 can also be controlled by changing the depth of the array structure of the structural color film 310. Therefore, the anti-counterfeiting label prepared by the preparation method provided in the present application can selectively hide and display the encrypted information, which is helpful to realize selective decryption and decoding of information, and further helps to realize higher information encryption and decoding. It provides a feasible scheme for high-level anti-counterfeiting and information encryption, and has important application prospect.

[0090] When acetonitrile is added to the structural color film 310, the acetonitrile fills the microarray structure of the structural color film 310, reducing the depth of the microarray structure of the structural color film 310, and thus reducing the diffraction effect and scattering effect of the microarray structure of the structural color film 310. The pattern of the perovskite film 210 can be displayed. When the acetonitrile is removed, the microarray structure is restored, and the diffraction effect and scattering effect are enhanced, and the pattern of the perovskite film 210 can be hidden, thereby selectively realizing the pattern display and hiding of the perovskite film 210. In addition, when the structural color film 310 is washed with acetonitrile, if the microarray structure of the structural color film 310 can be filled with acetonitrile, at this time, due to the filling of the array structure, the pattern of the structural color film 310 will be hidden, and when the acetonitrile is removed, the array structure is restored, and the pattern of the structural color film 310 will be displayed again, thereby realizing the pattern display and hiding of the structural color film 310. Since acetonitrile can be used as an eluent to remove unreacted diacetylene monomers when acetonitrile is added to the structural color film 310, that is, adding acetonitrile to the structural color film 310 can be a process step in the preparation process. That is, the pattern display and hiding of the perovskite film 210 and the structural color film 310 can be realized by using the process step of the preparation process itself, which is simple and convenient to operate and has strong practicality.

[0091] It should be noted that when acetonitrile is added to the structural color film 310, if the microarray structure depth of the structural color film 310 is shallow, the array structure can be filled with acetonitrile, and the structural color pattern can be hidden. If the microarray structure depth of the structural color film 310 is deep, the array structure will not be completely filled with acetonitrile, and the structural color pattern will not be hidden. This will be described in detail in subsequent embodiments.

[0092] Based on the foregoing embodiments, in an embodiment of the present application, forming the structural color film 310 on the side of the perovskite film 210 away from the substrate 100 further comprises:

[0093] The diacetylene layer is irradiated with irradiation light from the back surface of the substrate 100 to form the structural color film 310, wherein the back surface of the substrate 100 is opposite to the surface. It should be noted that the irradiation light can be ultraviolet light, but the present application does not limit this, which is determined according to the specific situation.

[0094] Specifically, after the diacetylene layer is irradiated with irradiation light through the first mask plate and the second mask plate, the light source of the irradiation light is moved to the back surface of the substrate 100 to irradiate the diacetylene layer from the back surface of the substrate 100 to form the structural color film 310. Since the diacetylene layer is directly irradiated with irradiation light from the back surface of the substrate 100, the thickness of the microarray structure of the structural color film 310 formed after irradiation with irradiation light will be reduced. When the thickness of the microarray structure of the structural color film 310 is reduced, the microarray structure of the structural color film 310 is more easily filled with acetonitrile, and the display and hiding of the structural color film 310 can be more easily achieved.

[0095] In addition, when the thickness of the microarray structure of the structural color film 310 is reduced, the diffraction effect and scattering effect of the microarray structure can be weakened, and the influence of the structural color film 310 on the pattern display of the perovskite film 210 can be reduced, thereby effectively solving the mutual interference between different optical modes.

[0096] Based on the foregoing embodiments, in an embodiment of the present application, as Figure 5As shown, the second preset pattern includes the first sub-pattern 311, that is, the pattern of the structural color film 310 includes the first sub-pattern 311, the first sub-pattern 311 includes the first part 3111 and the second part 3112 arranged in the first direction in sequence, and the corresponding second mask plate includes the first mask area, and the mask pattern of the first mask area is the same as the shape of the first sub-pattern 311. The first direction is parallel to the plane where the structural color film 310 is located, and is parallel to the periodic direction of the first mask area. The periodic direction of the first mask area is the arrangement direction of the grating periodic structure, and the periodic structure includes at least one slit. Based on this, the irradiation light irradiates the diacetylene layer in sequence through the first mask plate and the second mask plate, and forms the structural color film 310 including:

[0097] The irradiation light irradiates the diacetylene layer in sequence through the first mask plate and the first mask area.

[0098] Then, the irradiation light irradiates the second part through the back of the substrate 100, that is, the irradiation light irradiates the second part of the first sub-pattern through the back of the substrate 100, forms the structural color film 310, so that the depth of the microarray structure of the second part 3112 of the first sub-pattern 311 is less than the depth of the microarray structure of the first part of the first sub-pattern 311, as shown in the enlarged view of the middle area 1 and the area 2. Figure 5

[0099] Based on the above, continue as shown in Figure 5 If the incident direction of the second light beam is perpendicular to the first direction, as shown by the white arrow in Figure 5 , β represents the angle between the incident direction of the second light beam and the second direction, that is, the incident direction of the second light beam is perpendicular to the periodic direction of the first mask area, then the structural color film 310 can be irradiated by the second light beam to present the first sub-pattern 311; if the incident direction of the second light beam is perpendicular to the first direction, that is, the incident direction of the second light beam is perpendicular to the periodic direction of the first mask area, if the structural color film 310 is treated with acetonitrile, specifically, acetonitrile is added to the structural color film 310, at this time the microarray structure of the second part 3112 of the first sub-pattern 311 will be filled with acetonitrile, then the structural color film 310 can be irradiated by the second light beam to present the first part 3111 of the first sub-pattern 311, and the second part 3112 of the first sub-pattern 311 is hidden, when the acetonitrile is removed, the structural color film 310 can be irradiated by the second light beam to present the first sub-pattern 311 again, thereby realizing the selective hiding and displaying of each part of the first sub-pattern 311.

[0100] Based on the foregoing embodiments, in an embodiment of the present application, continue as shown in Figure 5 ​As shown, the second preset pattern further includes a second sub-pattern 312, i.e., the pattern of the structural color film 310 further includes the second sub-pattern 312, the first sub-pattern 311 and the second sub-pattern 312 are arranged along a second direction, and the second sub-pattern 312 includes a third part 3121 and a fourth part 3122 arranged along a first direction. Correspondingly, the second mask plate includes a second mask area, a mask pattern of the second mask area is the same as a shape of the second sub-pattern 312, the second direction is parallel to a plane where the structural color film 310 is located, and is parallel to a periodic direction of the second mask area, i.e., parallel to an arrangement direction of a periodic structure of the second mask area, and the second direction is perpendicular to the first direction. Based on this, the irradiation light irradiates the diacetylene layer through the first mask plate and the second mask plate in turn, to form the structural color film 310 including:

[0101] After the irradiation light passes through the first mask plate, the irradiation light irradiates the diacetylene layer through the first mask area and the second mask area.

[0102] Then, the irradiation light irradiates the second part 3112 and the fourth part 3122 through the back of the substrate 100, to form the structural color film 310, i.e., the irradiation light irradiates the second part 3112 of the first sub-pattern 311 and the fourth part 3122 of the second sub-pattern 312 through the back of the substrate 100, so that for the first sub-pattern 311, a thickness of the microarray structure of the second part 3112 is smaller than a thickness of the microarray structure of the first part 3111, and for the second sub-pattern 312, a thickness of the microarray structure of the fourth part 3122 is smaller than a thickness of the microarray structure of the third part 3121, as shown in the enlarged view of the middle area 3 and the area 4. Figure 5

[0103] Based on the above, as shown in Figure 5 If the incident direction of the second light beam is parallel to the first direction and perpendicular to the second direction, the structural color film 310 can be irradiated by the second light beam to present the second sub-pattern 312; if the incident direction of the second light beam is perpendicular to the second direction and the structural color film 310 is treated by acetonitrile, the structural color film 310 can be irradiated by the second light beam to present the third part 3122 of the second sub-pattern 312, and after the acetonitrile is removed, the structural color film 310 can be irradiated by the second light beam to present the second sub-pattern 312 again, thereby realizing selective hiding and displaying of each part of the second sub-pattern 312.

[0104] Based on the above, it can be further known that the display and hiding of the pattern of the structural color film 310 is no longer dependent on the incident direction of the second light beam, but can also be realized based on acetonitrile treatment, so that the anti-counterfeiting label prepared by the preparation method has a multiple stimulus response mechanism, which is helpful for the development of multi-mode anti-counterfeiting labels.

[0105] ​Based on the foregoing embodiments, in one embodiment of the present application, forming the structural color film 310 on the side of the perovskite film 210 away from the substrate 100 further comprises:

[0106] Placing a third mask plate above the surface of the substrate 100, the third mask plate is located between the first mask plate and the second mask plate, and the irradiation light is sequentially irradiated on the diacetylene layer through the first mask plate, the third mask plate and the second mask plate to form the structural color film 310.

[0107] Among them, the third mask plate is a grating with a second pitch, that is, the pitch between the grating structures of the third mask plate is a second pitch, and the second pitch is greater than the first pitch.

[0108] Forming the structural color film 310 on the side of the perovskite film 210 away from the substrate 100 further comprises:

[0109] Placing a fourth mask plate on the back of the substrate 100, and using irradiation light to irradiate the diacetylene layer through the fourth mask plate and the substrate 100 to form the structural color film 310. Among them, the fourth mask plate is a grating with a third pitch, and the third pitch is equal to the second pitch. It should be noted that the fourth mask plate can be the same grating as the third mask plate, that is, the fourth mask plate can be a reuse of the third mask plate, but the present application does not limit this, and the specific conditions are determined accordingly. It should also be noted that the first pitch can be in the range of 300 nm to 10 μm, including the end point value, and the second pitch and the third pitch can be in the range of 300 nm to 10 μm, including the end point value.

[0110] Specifically, in one embodiment of the present application, the first preset pattern is a chameleon, the second preset pattern is the letter "A", the slit pitch of the second mask plate is 1 μm, and the slit pitch of the third mask plate is 60 μm. 2,4-hexadiyne-1,6-diacrylate solution is mixed with photoinitiator (2-hydroxy-2-methylpropionone) at a ratio of 9:1 (v / v) to form a diacetylene liquid (referred to as HD-DA). 3 μL of HD-DA is added on the side of the perovskite film 310 away from the substrate 100, and ultraviolet light is irradiated on the HD-DA solution through the first mask plate (not shown in Figure 6 ) and the second mask plate Grating1 for 2 min. The first mask plate and the second mask plate are removed, and acetonitrile is used as an eluent to remove the unpolymerized HD-DA, to obtain a structural color film i, as shown in Figure 6 ). Ultraviolet light is irradiated on the HD-DA solution through the first mask plate and the second mask plate for 1 min, and then the light source is moved to the back of the substrate 100. Ultraviolet light is irradiated on the back of the substrate 100 for 2 min, the first mask plate and the second mask plate are removed, and acetonitrile is used as an eluent to remove the unpolymerized HD-DA, to obtain a structural color film ii, as shown in Figure 6The second preset pattern of the structural color film iv is shown in FIG. 7D. The UV light irradiates the diacetylene layer through the first mask plate, Grating 2 and the second mask plate Grating 1 in sequence for 2 min. Then, the light source and Grating 2 are moved to the back of the substrate 100. The UV light irradiates the diacetylene layer through the third mask plate and the substrate 100 for 6 min. The light source, the first mask plate, the second mask plate and the third mask plate are removed. The acetonitrile is used as an eluent to remove the unpolymerized HD-DA, and the structural color film iv is obtained, as shown in FIG. 7D. Figure 6 The second preset pattern of the structural color film iv is shown in FIG. 7D. The UV light irradiates the diacetylene layer through the first mask plate, Grating 2 and the second mask plate Grating 1 in sequence for 2 min. Then, the light source and Grating 2 are moved to the back of the substrate 100. The UV light irradiates the diacetylene layer through the third mask plate and the substrate 100 for 6 min. The light source, the first mask plate, the second mask plate and the third mask plate are removed. The acetonitrile is used as an eluent to remove the unpolymerized HD-DA, and the structural color film iv is obtained, as shown in FIG. 7D. Figure 6 The second preset pattern of the structural color film iv is shown in FIG. 7D. The UV light irradiates the diacetylene layer through the first mask plate, Grating 2 and the second mask plate Grating 1 in sequence for 2 min. Then, the light source and Grating 2 are moved to the back of the substrate 100. The UV light irradiates the diacetylene layer through the third mask plate and the substrate 100 for 6 min. The light source, the first mask plate, the second mask plate and the third mask plate are removed. The acetonitrile is used as an eluent to remove the unpolymerized HD-DA, and the structural color film iv is obtained, as shown in FIG. 7D.

[0111] Based on the above, as shown in FIG. 7A, the first preset pattern of the structural color film i is shown before and after the acetonitrile treatment and the removal of the acetonitrile. Figure 7 and Figure 8 , Figure 7 A is the first preset pattern corresponding to the structural color film i before and after the acetonitrile treatment and the removal of the acetonitrile, B is the first preset pattern corresponding to the structural color film ii before and after the acetonitrile treatment and the removal of the acetonitrile, C is the first preset pattern corresponding to the structural color film iii before and after the acetonitrile treatment and the removal of the acetonitrile, and D is the first preset pattern corresponding to the structural color film iv before and after the acetonitrile treatment and the removal of the acetonitrile. Figure 8 A is the first preset pattern corresponding to the structural color film i before and after the acetonitrile treatment and the removal of the acetonitrile, B is the first preset pattern corresponding to the structural color film ii before and after the acetonitrile treatment and the removal of the acetonitrile, C is the first preset pattern corresponding to the structural color film iii before and after the acetonitrile treatment and the removal of the acetonitrile, and D is the first preset pattern corresponding to the structural color film iv before and after the acetonitrile treatment and the removal of the acetonitrile. Figure 7 It can be known that based on the structural color film 310 microarray structure depth, combined with the acetonitrile treatment and the removal of the acetonitrile after the acetonitrile treatment, the selective hiding and display of the second preset pattern can be realized.

[0112] According to Figure 7 and Figure 8It can be seen that when the structural color film 310 is structural color film i, the array depth of structural color film 310 is relatively large, resulting in strong diffraction and scattering effects. This leads to a lower observed fluorescence intensity of the perovskite film 210. After acetonitrile treatment, the fluorescence intensity of the perovskite film 210 increases; however, after acetonitrile removal, the fluorescence intensity decreases again. Therefore, if structural color film i is used as the second anti-counterfeiting structure 300, the pattern of the perovskite film 210 can be selectively hidden or displayed. When the structural color film 310 is structural color film ii, the array depth of structural color film 310 is relatively small, and the diffraction and scattering effects are weak, so it will not affect the observed fluorescence intensity of the perovskite film 210. Therefore, if structural color film ii is used as the second anti-counterfeiting structure 300, the influence of the second anti-counterfeiting structure 300 on the first anti-counterfeiting structure 200 can be effectively avoided, that is, the mutual interference between different optical modes can be effectively avoided. When the structural color film 310 is structural color film iii, after acetonitrile treatment, the patterns of structural color film 310 and perovskite film 210 are displayed. After acetonitrile removal, the pattern of structural color film 310 is hidden, and the fluorescence intensity of perovskite film 210 is also greatly reduced. Therefore, if structural color film iii is used as the second anti-counterfeiting structure 300, the information of the first anti-counterfeiting structure 200 and the third anti-counterfeiting structure 300 can be hidden and displayed simultaneously. When the structural color film 310 is structural color film iv, the pattern of structural color film 310 can be hidden, while the display of the pattern of perovskite film 210 is not affected by the acetonitrile treatment.

[0113] Based on the above, the anti-counterfeiting label prepared by the improved preparation method of this application has multiple optical modes. These multiple optical modes can selectively hide or expose structural color information and fluorescence information based on the microarray structure of the structural color film 310 and external stimuli such as acetonitrile, so as to achieve a higher level of security information encryption and decryption.

[0114] Based on the foregoing embodiments, in one embodiment of this application, such as Figure 9 As shown, the second preset pattern includes a third sub-pattern 313 and a fourth sub-pattern 314. Correspondingly, the first mask includes a first sub-mask 11 and a second sub-mask 12. The mask pattern of the first sub-mask 11 is the same as that of the third sub-pattern 313, and the mask pattern of the second sub-mask 12 is the same as that of the fourth sub-pattern 314. The first mask and the second mask are sequentially placed above the surface of the substrate 100. Irradiation light sequentially passes through the first mask and the second mask to irradiate the diacetylene layer, forming a structural color thin film 310, including:

[0115] A first sub-mask 11 and a second mask are placed sequentially above the surface of the substrate 100, and the irradiation light irradiates the diacetylene layer sequentially through the first sub-mask 11 and the second mask.

[0116] The second mask is rotated 90° along a third direction, and a second sub-mask 12 is placed above it. Irradiation light sequentially passes through the second sub-mask 12 and the second mask to irradiate the diacetylene layer, forming a structural color film 310. The third direction is parallel to the mounting surface of the second mask. Specifically, the irradiation light sequentially passes through the first sub-mask 11 and the second mask to irradiate the diacetylene layer. Then, the first sub-mask 11 is removed, and the second mask is rotated 90° along its mounting surface. Irradiation light sequentially passes through the second sub-mask 12 and the second mask to irradiate the diacetylene layer, forming the structural color film 310.

[0117] Based on the above, if the incident direction of the second beam is perpendicular to the fourth direction and the fourth direction is parallel to the periodic direction before the second mask plate rotates, the structural color film 310 can be irradiated by the second beam to form a third sub-pattern 313; if the incident direction of the second beam is parallel to the fourth direction, the structural color film 310 can be irradiated by the second beam to form a fourth sub-pattern 314, thereby enabling the selective hiding and display of different patterns in the structural color film 310.

[0118] Specifically, in one embodiment of this application, such as Figure 9 As shown, the third sub-pattern 313 is a panda, and the fourth sub-pattern 314 is an elephant. A diacetylene liquid was formed by mixing a 2,4-hexanediyne-1,6-diacrylate solution with a photoinitiator (2-hydroxy-2-methylpropenone) at a ratio of 9:1 (v / v) and dropped onto the surface of substrate 100. Ultraviolet light was then applied to the HD-DA solution for 10 min through a first sub-mask 11 with a panda pattern and a second mask with a 1 μm spacing. The second mask was then rotated 90 degrees along its mounting surface. o The first sub-mask 11 was replaced with a second sub-mask 12 featuring an elephant pattern. Ultraviolet light was then sequentially irradiated through the second sub-mask 12 and the second mask for 10 min. All masks were removed, and unpolymerized HD-DA was removed using acetonitrile as the eluent, yielding a structural color film 310 with a specific periodic structure. Based on this structural color film 310, as the observation distance decreases (e.g., from L1=60cm to L2=35cm, then to L3=15cm), the panda pattern on the structural color film 310 first undergoes a color change, then transforms into an elephant pattern. It should be noted that when the incident angle of the second beam remains constant, the pattern display of the structural color film 310 is also related to the observation angle, which in turn is related to the observation distance. Therefore, as the observation distance decreases, the panda pattern on the structural color film 310 first undergoes a color change, then transforms into an elephant pattern.

[0119] In another embodiment of this application, such as Figure 10As shown, the third sub-pattern 313 is a two-dimensional code, and the fourth sub-pattern 314 is the word "Made in China". The 2,4-hexadiyne-1,6-diacrylate solution is mixed with a photoinitiator (2-hydroxy-2-methylpropionone) at a ratio of 9:1 (v / v) to form a diacetylene liquid, which is then dropped on the surface of the substrate 100. The HD-DA solution is irradiated by ultraviolet light through the first mask plate 11 with a two-dimensional code mask pattern and the second mask plate with a spacing of 1 μm for 2 min. Then, the second mask plate is rotated by 90° along its mounting surface, and the first mask plate 11 is replaced by the second mask plate 12 with a "Made in China" mask pattern. The HD-DA solution is irradiated by ultraviolet light through the second mask plate 12 and the second mask plate in turn for 2 min. All mask plates are removed, and the un-polymerized HD-DA is removed using acetonitrile as an eluent to obtain a structural color film 310 with a specific periodic structure. Based on the above-mentioned structural color film 310, the incident direction of the second light beam changes from perpendicular to the fourth direction to parallel to the fourth direction, and the pattern on the structural color film 310 can be observed to change from a two-dimensional code to a word. o As shown, the third sub-pattern 313 is a two-dimensional code, and the fourth sub-pattern 314 is the word "Made in China". The 2,4-hexadiyne-1,6-diacrylate solution is mixed with a photoinitiator (2-hydroxy-2-methylpropionone) at a ratio of 9:1 (v / v) to form a diacetylene liquid, which is then dropped on the surface of the substrate 100. The HD-DA solution is irradiated by ultraviolet light through the first mask plate 11 with a two-dimensional code mask pattern and the second mask plate with a spacing of 1 μm for 2 min. Then, the second mask plate is rotated by 90° along its mounting surface, and the first mask plate 11 is replaced by the second mask plate 12 with a "Made in China" mask pattern. The HD-DA solution is irradiated by ultraviolet light through the second mask plate 12 and the second mask plate in turn for 2 min. All mask plates are removed, and the un-polymerized HD-DA is removed using acetonitrile as an eluent to obtain a structural color film 310 with a specific periodic structure. Based on the above-mentioned structural color film 310, the incident direction of the second light beam changes from perpendicular to the fourth direction to parallel to the fourth direction, and the pattern on the structural color film 310 can be observed to change from a two-dimensional code to a word.

[0120] As can be seen from the above, the anti-counterfeiting label prepared by the preparation method can realize selective display and hiding of different structural color patterns, and the hiding and display of the above-mentioned structural color patterns are reversible, which has strong practicability. It should be noted that the application does not limit the ultraviolet irradiation time of different steps in the preparation process of different structural color patterns, which is determined according to the specific situation.

[0121] Based on the foregoing embodiments, in an embodiment of the present application, forming a perovskite film 210 on the surface of the substrate 100 comprises:

[0122] The CsPbX3 perovskite nanocrystal n-hexane solution is added to the silicone elastomer to form a perovskite mixture.

[0123] The perovskite mixture is coated with a first preset pattern on the surface of the substrate 100 to form a perovskite film 210. The perovskite film is a CsPbX3 perovskite film, and X is Br, Cl or I.

[0124] Specifically, the CsPbCl3 perovskite nanocrystal n-hexane solution is added to the mixture of Sylgard 184 silicone elastomer to form a perovskite mixture, a first preset pattern of fluorescent pattern is prepared by inkjet printing technology, and is fixed and formed by vacuum drying at 60 °C for 3 h to form a perovskite film. It should be noted that in other embodiments of the present application, the first preset pattern of fluorescent pattern can also be prepared by screen printing, spraying or dotting, etc. to obtain the perovskite film 210, and the present application does not limit this, which is determined according to the specific situation.

[0125] Based on the foregoing embodiments, in one embodiment of the present application, forming the first anti-counterfeiting structure 200 further comprises:

[0126] As shown in FIG. 2, a silver nanowire layer 220 is formed on the side of the perovskite film 210 away from the substrate 100. Figure 2 As shown in FIG. 2, a silver nanowire layer 220 is formed on the side of the perovskite film 210 away from the substrate 100.

[0127] Forming the silver nanowire layer 220 on the side of the perovskite film 210 away from the substrate 100 comprises:

[0128] A first silver nanowire layer 221 is formed on the side of the perovskite film 210 away from the substrate 100, and the orientation of the first silver nanowire layer 221 is a first angle.

[0129] A second silver nanowire layer 222 is formed on the side of the first silver nanowire layer 221 away from the substrate 100, and the orientation of the second silver nanowire layer 222 is a second angle. The first angle and the second angle are different, that is, there is a twist angle between the first silver nanowire layer 221 and the second silver nanowire layer 222 to form a twisted stacked silver nanowire layer 220. It should be noted that the twist angle between the first silver nanowire layer 221 and the second silver nanowire layer 222 can be in the range of -90° to 90°, and the specific value can be determined as appropriate.

[0130] Specifically, depositing the twisted stacked silver nanowire layer (abbreviated as AgNWs) on the side of the perovskite film 210 away from the substrate 100 comprises: depositing the first silver nanowire layer 221, specifically taking 3ml of AgNWs solution, and dropping it to the center of the surface of the container filled with ethylene glycol (the diameter is 15cm), and the injection rate is 20ml / h. After the injection is completed, immediately drop the cetyltrimethylammonium chloride aqueous solution (abbreviated as CTAC) in the center of the container to induce the alignment of AgNWs at the edge of the liquid. After the solvent evaporates, the AgNWs are transferred to the surface of the perovskite film 210 in a directional manner. And before depositing the second silver nanowire layer 222, rotate the substrate 100 and the perovskite film 210 in a clockwise or counterclockwise direction at a pre-designed angle, and then deposit the second silver nanowire layer 222 to obtain the twisted stacked silver nanowire layer 220. It should be noted that the deposition of the above silver nanowire layer 220 can be realized by LB film method, dip-coating method, etc., but the present application does not limit it, and the specific value can be determined as appropriate. In one embodiment of the present application, the CTAC can be 100 mM, 3 mL, but the present application does not limit it, and the specific value can be determined as appropriate.

[0131] Based on the above, in one preferred embodiment of the present application, the first angle is 45° and the second angle is -45°, so that the chirality of the first silver nanowire layer 221 and the second silver nanowire layer 222 is maximum and opposite, and thus when observing the perovskite film 210 through the silver nanowire layer 220 using a left-handed circular polarizer and a right-handed circular polarizer, the perovskite film 210 can exhibit the characteristics of a chiral fluorescent layer.

[0132] Based on the above, in one embodiment of the present application, as shown in Figure 11 the perovskite film is a CsPbBr3 perovskite film, and the first predetermined pattern includes a fifth sub-pattern 211 and a sixth sub-pattern 212. If the fifth sub-pattern 211 of the perovskite film 210 is observed using a left-handed circular polarizer (L-CPF) and appears blue, and if the sixth sub-pattern 212 of the perovskite film 210 is observed using a right-handed circular polarizer (R-CPF) and appears red, the fifth sub-pattern 211 and the sixth sub-pattern 212 can be directly observed by the naked eye (Naked eye). Since the first angle is 45° and the second angle is -45°, the chirality of the first silver nanowire layer 221 and the second silver nanowire layer 222 is opposite, and thus when observing the perovskite film 210 through the silver nanowire layer 220 using a left-handed circular polarizer and a right-handed circular polarizer, the fifth sub-pattern 211 appears blue when observed through the silver nanowire layer 220 using a left-handed circular polarizer, and the sixth sub-pattern 212 appears red when observed through the silver nanowire layer 220 using a right-handed circular polarizer.

[0133] In addition, in the present embodiment, the perovskite film is a CsPbBr3 perovskite film, and thus if the first security structure 200 is treated with HCl, the fluorescence wavelength of the perovskite film 210 is blue-shifted, and if the first security structure is treated with HI, the fluorescence wavelength of the perovskite film 210 is red-shifted, which is specifically manifested as a blue-shift of the fluorescence emission peak of the perovskite film 210 and a red-shift of the fluorescence emission peak of the perovskite film 210. As shown in Figure 12 Figure 12 wherein a and b are the changes in the fluorescence color of the perovskite film 210 under white light and ultraviolet light excitation during halogen anion exchange. As can be seen, the prepared security label has a chiral feature of the fluorescent pattern that can be dynamically modulated by halogen anion exchange, i.e., the fluorescence color of the perovskite film 210 can be regulated by halogen anion exchange, and at the same time, opposite chiral features can be exhibited in the red fluorescence and blue fluorescence ranges, which is helpful for the application of multi-mode security labels in the field of high-level security.

[0134] ​Based on the above, in one specific embodiment of the present application, the CsPbCl3 perovskite nanocrystal n-hexane solution is added to the mixture of Sylgard 184 silicone elastomer to form a perovskite mixture, a first preset pattern of fluorescent patterns is prepared by inkjet printing technology, the first preset pattern is a butterfly, and is fixed and shaped by 60℃ vacuum drying for 3h to form a perovskite thin film with a butterfly pattern. Then, a twisted stacked silver nanowire layer 220 is deposited on the surface of the perovskite thin film 210. Continue as shown in Figure 11 The perovskite thin film 210 is observed through the left-handed circular polarizer and the right-handed circular polarizer, and the blue left half wing and the red right half wing can be observed respectively, and the naked eye can observe the whole butterfly pattern.

[0135] In order to more clearly understand the preparation method of the anti-counterfeiting label provided by the present application, two specific embodiments are described in detail below.

[0136] Example 1: as shown in Figure 13 , Figure 13Structure "ii" represents the structural color film, CPL layer represents the perovskite film, SC represents the structural color pattern, FL represents the fluorescent pattern, and CPL represents the fluorescent chiral pattern. The chameleon fluorescent pattern was prepared by inkjet printing technology with a mixture of CsPbBr3perovskite nanocrystal n-hexane solution and perovskite of silicone elastomer crystal PDMS, and vacuum dried at 60 °C for 3 h to form a perovskite film 210, and the first preset pattern is a chameleon. Then a twisted stack of silver nanowire layer 220 was deposited on the surface of the perovskite film 210. A layer of polyethylene film 230 was deposited on the surface of the silver nanowire layer 220 and was subjected to plasma treatment (60 mW, 10 min). A diacetylene liquid was formed by mixing 2,4-hexadiyne-1,6-diacrylate (HD-DA) solution and photoinitiator (2-hydroxy-2-methylpropionone) at a ratio of 9:1 (v / v). 3 μL of the diacetylene liquid was added to the surface of the silver nanowire layer 220 to form a diacetylene layer. The UV light was irradiated on the diacetylene layer for 30 s through the first sub-mask plate and the second mask plate in sequence. Then the light source and the first sub-mask plate were moved to the back of the substrate 100, and the UV light was irradiated on the diacetylene layer for 2 min through the first sub-mask plate, then through the back of the substrate 100. The mask pattern of the first sub-mask plate was "window flower", the second mask plate was a grating with a pitch of 1 μm, and the first sub-mask plate was mirror image of the first sub-mask plate on the front of the substrate 100. Then the second mask plate was rotated 90° along its mounting surface, the light source was moved to the surface of the substrate 100, and the UV light was irradiated on the diacetylene layer for 30 s through the second sub-mask plate and the second mask plate in sequence. Then the light source and the second sub-mask plate were moved to the back of the substrate 100, and the UV light was irradiated on the diacetylene layer for 2 min through the second sub-mask plate, then through the back of the substrate 100. The mask pattern of the second sub-mask plate was a flower, and the second sub-mask plate was mirror image of the second sub-mask plate on the front of the substrate 100. Finally, all the mask plates were removed, and acetonitrile was used as an eluent to remove the un-polymerized polydiacetylene, to obtain a structural color film 310 with a composite pattern.

[0137] Based on the above, the microarray structure of the structural color film 310 with a composite pattern is the same as that of the aforementioned structural color film ii, so that the structural color film 310 with a composite pattern can change the incident direction of the second light beam under white light, so that the structural color pattern can change from "window flower" pattern to "flower" pattern, and the structural color pattern is hidden after being washed with acetonitrile, and does not affect the fluorescent pattern and the chiral characteristics of the underlying perovskite film 210. Similarly, the fluorescent pattern and the chiral characteristics of the perovskite film 210 can also be tuned by anion exchange without interfering with the structural color image.

[0138] In addition, according to Figure 13It is also known that if the chameleon fluorescent pattern is treated with HI, a blue chameleon pattern can be seen when observed through a left-handed circular polarizer, while no pattern is observed when observed through a right-handed circular polarizer, and the blue chameleon pattern can be seen with the naked eye. If the chameleon pattern is treated with HI in a specified area, it will change from blue to red, and the chameleon pattern composed of blue and red fluorescence can be observed with the naked eye. When observed with a left-handed polarizer or a right-handed polarizer, only the blue or red part can be detected. If the chameleon fluorescent pattern is treated with HCl, a red chameleon pattern can be seen when observed through a right-handed circular polarizer, while no pattern is observed when observed through a right-handed circular polarizer, and the red chameleon pattern can be seen with the naked eye.

[0139] Example 2: As Figure 14 shown, SC represents the structural color pattern, FL represents the fluorescent pattern on the back of the substrate 100, and CPL represents the fluorescent chiral pattern on the back of the substrate 100. Specifically, a fluorescent pattern of the Chinese character "Ke" is prepared by inkjet printing a perovskite mixture of CsPbBr3 perovskite nanocrystals in n-hexane solution and polydimethylsiloxane (PDMS) organic silicone elastomer crystals, and vacuum drying at 60 °C for 3 h to form a perovskite thin film 210. The first preset pattern is the Chinese character "Ke". Then, a layer of twisted and stacked silver nanowire layer 220 is deposited on the surface of the perovskite thin film 210. A polyethylene thin film is deposited on the surface of the silver nanowire layer 220 and subjected to plasma treatment (60 mW, 10 min). A solution of 2,4-hexadiyne-1,6-diacrylate (HD-DA) and a photoinitiator (2-hydroxy-2-methylpropiophenone) are mixed in a ratio of 9:1 (v / v) to form a diacetylene liquid. 3 μL of the diacetylene liquid is dropped on the surface of the above silver nanowire layer 220 to form a diacetylene layer. Ultraviolet light irradiates the diacetylene layer for 10 min successively through the first mask plate, the third mask plate, and the second mask plate. Then, the light source and the third mask plate are moved to the back of the substrate 100, and the rabbit pattern on the structural color thin film 310 is blocked. Ultraviolet light passes through the third mask plate and the back of the substrate 100 in turn and then irradiates the diacetylene layer for 6 min. The mask pattern of the first sub-mask plate is a rabbit pattern, the second mask plate is a grating with a pitch of 1 μm, and the third mask plate is a grating with a pitch of 60 μm. After removing all the mask plates, acetonitrile is used as an eluent to remove the unpolymerized polydiacetylene, and the structural color thin film 310 with a rabbit pattern is obtained. The special feature of this example is that there are different microarray structures on the structural color thin film 310. Specifically, the microarray structure in the area of the rabbit pattern on the structural color thin film 310 is the same as the microarray structure of the aforementioned structural color thin film iii, while the microarray structure in the area other than the rabbit pattern is the same as the microarray structure of the aforementioned structural color thin film iv.

[0140] Based on the above, for the structural color film 310 in the present embodiment, when the surface of the structural color film 310 is in the acetonitrile infiltration state, the rabbit pattern of the structural color mode and the Chinese character "Ke" of the fluorescent mode will appear. The perovskite film on the back of the substrate 100 can be changed from blue to red by HI treatment, and the above color change process can also be used to achieve reversible change using HCl treatment. In addition, in the fluorescent mode, by using left / right circular polarizers, the Chinese characters "He" and "Dou" can also be observed respectively. It should be noted that, due to the fluorescent signals of CsPbCl3 and CsPbI3 having exactly opposite signs, this leads to the order of disappearance and appearance of the Chinese characters "He" and "Dou" being exactly opposite. And due to the smaller asymmetric factor Glum of CsPbBr3, the perovskite film can only get the Chinese character "Ke" under the observation of left / right circular polarizers.

[0141] Based on the above embodiment, the anti-counterfeiting label prepared in the present application combines the multi-mode dynamic label of adjustable structural color, fluorescence and CPL information, and has great potential in the field of high-level anti-counterfeiting. And during the dynamic adjustment process of the anti-counterfeiting label, the adjustable structural color, fluorescence and CPL information can be selectively realized by the microarray structure of the upper structural color film to realize the regulation of the interference mode and the orthogonal mode, which has great potential in the field of high-level anti-counterfeiting.

[0142] The present application also provides an anti-counterfeiting label, as shown in the figure, the anti-counterfeiting label comprises: Figure 2 The substrate 100.

[0143] The substrate 100.

[0144] The first anti-counterfeiting structure 200 and the second anti-counterfeiting structure 300 are arranged in sequence on the surface of the substrate 100, the first anti-counterfeiting structure 200 comprises a perovskite film 210 on the surface of the substrate 100, the shape of the perovskite film 210 is a first preset pattern, and the perovskite film 210 can be irradiated by a first light beam to form the first preset pattern; the second anti-counterfeiting structure 300 comprises a structural color film 310 formed on the side of the perovskite film 210 away from the substrate 100, the shape of the structural color film 310 is a second preset pattern, and the structural color film 310 can be irradiated by a second light beam to form the second preset pattern.

[0145] The structural color film 310 is irradiated by the first mask plate and the second mask plate in sequence, the pattern of the first mask plate is the same as the second preset pattern, and the second mask plate is a first pitch grating.

[0146] As known from the above, the structural color film 310 is obtained by irradiating light through the first mask plate and the second mask plate in sequence, and the second mask plate is a grating, so the structural color film 310 has a microarray structure. Due to the diffraction effect and scattering effect of the microarray structure, when the perovskite film 210 is excited to emit light, the fluorescence intensity of the perovskite film 210 transmitted through the structural color film 310 will be affected by the diffraction effect and scattering effect. The stronger the diffraction effect and scattering effect, the lower the fluorescence intensity after the structural color film 310. On the contrary, the fluorescence intensity is stronger. The diffraction effect and scattering effect of the structural color film 310 are related to the depth of the array structure, so for the anti-counterfeiting label provided in the application, the pattern display of the perovskite film 210 can be controlled by changing the depth of the array structure of the structural color film 310. Specifically, the pattern display of the perovskite film 210 can be controlled by changing the depth of the array structure of the structural color film 310 to hide or display the pattern of the perovskite film 210. At the same time, the depth of the microarray structure of the structural color film 310 can also affect the pattern display and hiding of the structural color film 310, that is, the pattern display and hiding of the structural color film 310 can also be controlled by changing the depth of the array structure of the structural color film 310. Therefore, the anti-counterfeiting label provided in the application can selectively hide and display encrypted information, which is helpful to realize selective decryption and decoding of information, and further helps to realize higher information encryption and decoding, and provides a feasible scheme for high-level anti-counterfeiting and information encryption, which has important application prospects.

[0147] Based on the foregoing embodiments, in an embodiment of the application, the first anti-counterfeiting structure 200 further comprises:

[0148] A silver nanowire layer 220 is formed on the side of the perovskite film 210 away from the surface of the substrate 100, which includes a first silver nanowire layer 221 formed on the side of the perovskite film 210 away from the surface of the substrate 100, and a second silver nanowire layer 222 formed on the side of the first silver nanowire layer 221 away from the surface of the substrate 100.

[0149] Wherein, the orientation of the first silver nanowire layer 221 is a first angle, the orientation of the second silver nanowire layer 222 is a second angle, the first angle and the second angle are different, that is, there is a twist angle between the first silver nanowire layer 221 and the second silver nanowire layer 222, so as to form a twisted stacked silver nanowire layer 220.

[0150] Based on the above, in one preferred embodiment of the present application, the first angle is 45° and the second angle is -45°, so that the chirality of the first silver nanowire layer 221 and the second silver nanowire layer 222 is maximum and opposite, and then when the left-handed circular polarizer and the right-handed circular polarizer are used to observe the perovskite film 210 through the silver nanowire layer 220, the perovskite film 210 can exhibit the characteristics of a chiral fluorescent layer.

[0151] In summary, the present application provides a preparation method of a security label and a security label. The preparation method comprises: sequentially forming a first security structure and a second security structure arranged in layers on a surface of a substrate. The first security structure is formed by forming a perovskite film on the surface of the substrate, and the perovskite film can be irradiated by a first light beam to exhibit a first preset pattern. The second security structure is formed by forming a structural color film on a side of the perovskite film away from the substrate, and the structural color film can be irradiated by a second light beam to exhibit a second preset pattern. The structural color film is formed by forming a diacetylene layer on the side of the perovskite film away from the substrate, irradiating the diacetylene layer by the first mask plate and the second mask plate in sequence to form the structural color film, and treating the structural color film with acetonitrile. The pattern of the first mask plate is the same as the second preset pattern, and the second mask plate is a grating with a first pitch.

[0152] As described above, the structural color film is obtained by irradiating the diacetylene layer by the first mask plate and the second mask plate in sequence, and the second mask plate is a grating. Therefore, the structural color film has a microarray structure. Due to the diffraction effect and scattering effect of the microarray structure, the fluorescence intensity of the perovskite film transmitted through the structural color film is affected by the diffraction effect and scattering effect of the structural color film, and the diffraction effect and scattering effect of the structural color film are related to the depth of the array structure. Therefore, for the security label prepared by the preparation method provided by the present application, the display of the pattern of the perovskite film can be controlled by changing the depth of the array structure of the structural color film, so that the pattern of the perovskite film can be selectively hidden or displayed. In addition, the depth of the microarray structure of the structural color film can also affect the display and hiding of the pattern of the structural color film, so that the display and hiding of the pattern of the structural color film can also be controlled by changing the depth of the array structure of the structural color film. Therefore, the security label prepared by the preparation method provided by the present application can selectively hide and display the encrypted information, which is helpful to selectively decrypt and decode the information, and further helps to realize higher information encryption and decoding, thereby providing a feasible solution for high-level security and information encryption, and having important application prospects.

[0153] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical areas between embodiments can be referred to interchangeably. For the apparatuses disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant details can be found in the description of the method area.

[0154] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0155] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0156] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing an anti-counterfeiting label, characterized in that, include: Provide a base; A first anti-counterfeiting structure and a second anti-counterfeiting structure are formed in sequence on the surface of the substrate; The formation of the first anti-counterfeiting structure includes: A perovskite film is formed on the surface of the substrate. The perovskite film has a first preset pattern and can be irradiated by a first light beam to form the first preset pattern. The second anti-counterfeiting structure includes: A structural color film is formed on the side of the perovskite film away from the substrate. The shape of the structural color film is a second preset pattern. The structural color film can be irradiated by a second light beam to present the second preset pattern. The formation of the structural color film on the side of the perovskite film facing away from the substrate includes: Diacetylene liquid is dropped onto the side of the perovskite film opposite to the substrate to form a diacetylene layer, wherein the diacetylene liquid has a diacetylene monomer; A first mask and a second mask are placed sequentially above the surface of the substrate. Irradiation light passes sequentially through the first mask and the second mask to irradiate the diacetylene layer, forming the structural color film. Acetonitrile is added dropwise to the structural color film to treat the structural color film; The pattern of the first mask is the same as the second preset pattern, and the second mask is a grating with a first spacing.

2. The method for preparing the anti-counterfeiting label according to claim 1, characterized in that, Forming a structural color film on the side of the perovskite film opposite to the substrate further includes: Irradiated light shines on the diacetylene layer through the back side of the substrate to form the structural color film; The back side of the substrate is opposite to the surface of the substrate.

3. The method for preparing the anti-counterfeiting label according to claim 2, characterized in that, The second preset pattern includes a first sub-pattern, the first sub-pattern includes a first part and a second part arranged along a first direction, the second mask includes a first mask area, the first direction is parallel to the plane where the structural color film is located, and parallel to the periodic direction of the first mask area; Irradiation light sequentially passes through the first mask and the second mask to irradiate the diacetylene layer, forming the structural color film, comprising: The irradiation light sequentially passes through the first mask plate and the first mask region to irradiate the diacetylene layer; Subsequently, the irradiated light shines on the second part through the back side of the substrate to form the structural color film; Wherein, if the incident direction of the second beam is perpendicular to the first direction, the structural color film can be irradiated by the second beam to form the first sub-pattern; if the incident direction of the second beam is perpendicular to the first direction, and the structural color film is treated with acetonitrile, the structural color film can be irradiated by the second beam to form the first part of the first sub-pattern.

4. The method for preparing the anti-counterfeiting label according to claim 3, characterized in that, The second preset pattern further includes a second sub-pattern. The first sub-pattern and the second sub-pattern are arranged along a second direction. The second sub-pattern includes a third part and a fourth part arranged along the first direction. The second mask plate includes a second mask area. The second direction is parallel to the plane where the structural color film is located and parallel to the periodic direction of the second mask area. The second direction is perpendicular to the first direction. Irradiation light sequentially passes through the first mask and the second mask to irradiate the diacetylene layer, forming the structural color film, comprising: After passing through the first mask plate, the irradiated light irradiates the diacetylene layer through the first mask region and the second mask region; Subsequently, the irradiated light shines on the second part and the fourth part through the back side of the substrate to form the structural color film; Wherein, if the incident direction of the second beam is parallel to the first direction and perpendicular to the second direction, the structural color film can be irradiated by the second beam to form the second sub-pattern; if the incident direction of the second beam is perpendicular to the second direction, and the structural color film is treated with acetonitrile, the structural color film can be irradiated by the second beam to form the third part of the second sub-pattern.

5. The method for preparing the anti-counterfeiting label according to claim 1, characterized in that, Forming a structural color film on the side of the perovskite film opposite to the substrate further includes: A third mask is placed above the substrate surface, and the third mask is located between the first mask and the second mask. Irradiation light passes sequentially through the first mask, the third mask and the second mask to irradiate the diacetylene layer, forming the structural color film. The third mask is a grating with a second spacing, which is greater than the first spacing.

6. The method for preparing the anti-counterfeiting label according to claim 5, characterized in that, Forming a structural color film on the side of the perovskite film opposite to the substrate further includes: A fourth mask is placed on the back of the substrate, and the diacetylene layer is irradiated sequentially through the fourth mask and the substrate using irradiation light to form the structural color film; The fourth mask is a grating with a third spacing, which is equal to the second spacing.

7. The method for preparing the anti-counterfeiting label according to claim 1, characterized in that, The second preset pattern includes a third sub-pattern and a fourth sub-pattern. The first mask includes a first sub-mask and a second sub-mask. The pattern of the first sub-mask is the same as the third sub-pattern, and the pattern of the second sub-mask is the same as the fourth sub-pattern. The first mask and the second mask are placed sequentially above the substrate surface. Irradiation light sequentially passes through the first mask and the second mask to irradiate the diacetylene layer, forming the structural color film by: The first sub-mask and the second mask are placed sequentially above the surface of the substrate, and the irradiation light irradiates the diacetylene layer sequentially through the first sub-mask and the second mask; The second mask is rotated 90° along a third direction, and a second sub-mask is placed above the second mask. Irradiation light sequentially passes through the second sub-mask and the second mask to irradiate the diacetylene layer, forming the structural color film; wherein, the third direction is parallel to the mounting surface of the second mask; If the incident direction of the second beam is perpendicular to the fourth direction, and the fourth direction is parallel to the periodic direction before the second mask plate rotates, the structural color film can be irradiated by the second beam to form the third sub-pattern; if the incident direction of the second beam is parallel to the fourth direction, the structural color film can be irradiated by the second beam to form the fourth sub-pattern.

8. The method for preparing the anti-counterfeiting label according to claim 1, characterized in that, Forming a perovskite thin film on the substrate surface includes: A hexane solution of CsPbX3 perovskite nanocrystals was added to an organosilicon elastomer to form a perovskite mixture. The perovskite mixture is coated onto the substrate surface with the first preset pattern to form the perovskite film. The perovskite film is a CsPbX3 perovskite film, where X is Br, Cl, or I.

9. The method for preparing the anti-counterfeiting label according to claim 8, characterized in that, The first anti-counterfeiting structure also includes: A silver nanowire layer is formed on the side of the perovskite film opposite to the substrate. The formation of a silver nanowire layer on the side of the perovskite film opposite to the substrate includes: A first silver nanowire layer is formed on the side of the perovskite film away from the substrate, and the orientation of the first silver nanowire layer is at a first angle. A second silver nanowire layer is formed on the side of the first silver nanowire layer away from the substrate, and the orientation of the second silver nanowire layer is at a second angle. The first angle and the second angle are different.

10. The method for preparing the anti-counterfeiting label according to claim 9, characterized in that, The first angle is 45°, and the second angle is -45°.

11. The method for preparing the anti-counterfeiting label according to claim 9, characterized in that, The perovskite film is a CsPbBr3 perovskite film, and the first preset pattern includes a fifth sub-pattern and a sixth sub-pattern. If the perovskite film is observed using a left-handed circular polarizer, it appears as a blue fifth sub-pattern; if the perovskite film is observed using a right-handed circular polarizer, it appears as a red sixth sub-pattern. If the first anti-counterfeiting structure is treated with HCl, the fluorescence wavelength of the perovskite film will shift blue; if the first anti-counterfeiting structure is treated with HI, the fluorescence wavelength of the perovskite film will shift red.

12. An anti-counterfeiting label, characterized in that, The anti-counterfeiting label is a location label prepared using the preparation method according to any one of claims 1-11, comprising: Base; A first anti-counterfeiting structure and a second anti-counterfeiting structure are sequentially stacked on the surface of the substrate. The first anti-counterfeiting structure includes a perovskite film located on the surface of the substrate. The perovskite film has a first preset pattern and can be irradiated by a first light beam to present the first preset pattern. The second anti-counterfeiting structure includes a structural color film formed on the side of the perovskite film opposite to the substrate. The structural color film has a second preset pattern and can be irradiated by a second light beam to present the second preset pattern. The structural color film is formed by irradiating light sequentially through a first mask and a second mask. The pattern of the first mask is the same as the second preset pattern, and the second mask is a grating with a first spacing.

13. The anti-counterfeiting label according to claim 12, characterized in that, The first anti-counterfeiting structure also includes: A silver nanowire layer is formed on the side of the perovskite film away from the substrate. The silver nanowire layer includes a first silver nanowire layer formed on the side of the perovskite film away from the substrate, and a second silver nanowire layer formed on the side of the first silver nanowire layer away from the substrate. The first silver nanowire layer is oriented at a first angle, and the second silver nanowire layer is oriented at a second angle, wherein the first angle and the second angle are different.

14. The anti-counterfeiting label according to claim 13, characterized in that, The first angle is 45°, and the second angle is -45°.

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