Preparation method of anti-counterfeit label and anti-counterfeit label

Abstract

The invention provides a preparation method of an anti-counterfeit label and the anti-counterfeit label, and the preparation method comprises the steps: sequentially forming a first anti-counterfeit structure and a second anti-counterfeit structure which are stacked on the surface of a substrate, and forming the first anti-counterfeit structure comprises forming a perovskite thin film on the surface of the substrate, the perovskite thin film can be irradiated by a first light beam to form a first preset pattern, and forming of the second anti-counterfeiting structure comprises forming a structural color thin film on the side, away from the substrate, of the perovskite thin film, and the structural color thin film can be irradiated by a second light beam to form a second preset pattern. Wherein the structural color film is formed by sequentially irradiating irradiation light through a first mask plate and a second mask plate, a mask pattern of the first mask plate is the same as a second preset pattern, and the second mask plate is a grating with a first interval, so that the structural color film is of a microarray structure; structural color patterns and fluorescent patterns can be selectively hidden and displayed based on the microarray structure, and then information encryption of the anti-fake structure is achieved.

Description

Technical Field

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

[0002] Information encryption and anti-counterfeiting have always been hot issues of long-term social concern. Related research involves multidisciplinary intersections, such as materials science, information technology, optics, chemistry, etc. Its continuous development has also promoted scientific and technological progress and innovation in related fields.

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

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

[0005] A method for preparing an anti-counterfeiting label, comprising:

[0006] providing a substrate;

[0007] Forming a first anti-counterfeiting structure and a second anti-counterfeiting structure which are sequentially stacked 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, wherein the shape of the perovskite film is a first preset pattern, and the perovskite film can be irradiated by a first light beam to form 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, wherein 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 present a second preset pattern;

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

[0013] Dropping a diacetylene liquid on a side of the perovskite film away from the substrate to form a diacetylene layer, wherein the diacetylene liquid contains a diacetylene monomer;

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

[0015] adding acetonitrile dropwise to the structural color film to treat the structural color film with acetonitrile;

[0016] The pattern of the first mask is the same as the second preset pattern, and the second mask is a grating with a first pitch.

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

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

[0019] Wherein, the back side 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 portion and a second portion arranged along a first direction, the second mask plate includes a first mask area, the first direction is parallel to the plane where the structural color film is located, and is parallel to the periodic direction of the first mask area; the irradiation light sequentially irradiates the diacetylene layer through the first mask plate and the second mask plate to form the structural color film, comprising:

[0021] The irradiation light sequentially irradiates the diacetylene layer through the first mask plate and the first mask area;

[0022] Afterwards, irradiating light irradiates the second portion through the back side of the substrate to form the structural color film;

[0023] Among them, if 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; if 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 the 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 portion and a fourth portion 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 is parallel to the periodic direction of the second mask area, and the second direction is perpendicular to the first direction; the irradiation light sequentially irradiates the diacetylene layer through the first mask plate and the second mask plate to form the structural color film, comprising:

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

[0026] Afterwards, irradiating light irradiates the second portion and the fourth portion through the back side of the substrate to form the structural color film;

[0027] Among them, 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 with 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, forming a structural color film on a side of the perovskite film away from the substrate further comprises:

[0029] A third mask is placed above the surface of the substrate, the third mask is located between the first mask and the second mask, and the irradiation light passes through the first mask, the third mask and the second mask in sequence to irradiate the diacetylene layer to form the structural color thin film;

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

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

[0032] placing a fourth mask plate on the back of the substrate, and irradiating the diacetylene layer through the fourth mask plate and the substrate in sequence with irradiation light to form the structural color thin film;

[0033] 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 includes a third sub-pattern and a fourth sub-pattern, the first mask plate includes 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 first mask plate and the second mask plate are sequentially placed above the surface of the substrate, and the irradiation light sequentially passes through the first mask plate and the second mask plate to irradiate the diacetylene layer, and forming the structural color thin film includes:

[0035] The first sub-mask plate and the second mask plate are sequentially placed above the surface of the substrate, and the irradiation light sequentially irradiates the diacetylene layer through the first sub-mask plate and the second mask plate;

[0036] The second mask plate is rotated 90 degrees along the third direction, and a second sub-mask plate is placed above the second mask plate, and the irradiation light sequentially passes through the second sub-mask plate and the second mask plate to irradiate the diacetylene layer to form the structural color thin 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 the fourth direction, and the fourth direction is parallel to the periodic direction of the second mask before rotation, 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, forming a perovskite film on the surface of the substrate comprises:

[0039] adding a n-hexane solution of CsPbX3 perovskite nanocrystals to a silicone elastomer to form a perovskite mixture;

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

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

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

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

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

[0045] forming a first silver nanowire layer on a side of the perovskite film facing away from the substrate, wherein the first silver nanowire layer is oriented at a first angle;

[0046] forming a second silver nanowire layer on a side of the first silver nanowire layer away from the substrate, wherein the second silver nanowire layer is oriented at 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 includes a fifth sub-pattern and a sixth sub-pattern;

[0050] When the perovskite film is observed using a left-handed circular polarizer, the fifth sub-pattern appears blue, and when the perovskite film is observed using a right-handed circular polarizer, the sixth sub-pattern appears red.

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

[0052] An anti-counterfeiting label, characterized by comprising:

[0053] substrate;

[0054] A first anti-counterfeiting structure and a second anti-counterfeiting structure are sequentially stacked and arranged on the surface of the substrate;

[0055] The first anti-counterfeiting structure includes a perovskite film located 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 present the first preset pattern; the second anti-counterfeiting structure includes a structural color film located 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 present a second preset pattern;

[0056] The structural color film is formed by irradiating light through a first mask plate and a 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 grating with a first pitch.

[0057] Optionally, the first anti-counterfeiting structure further includes:

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

[0059] The first silver nanowire layer is oriented at a first angle, the second silver nanowire layer is oriented at 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 solution of this application has the following beneficial effects:

[0062] The preparation method comprises: forming a first anti-counterfeiting structure and a second anti-counterfeiting structure in a stacked arrangement on the surface of a substrate in sequence, wherein the first anti-counterfeiting structure comprises forming a perovskite film on the surface of the substrate, wherein the perovskite film can be irradiated by a first light beam to present a first preset pattern, and the second anti-counterfeiting structure comprises forming a structural color film on the side of the perovskite film away from the substrate, wherein the structural color film can be irradiated by a second light beam to present a second preset pattern. Forming a 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 through a first mask plate and a second mask plate in sequence to form a 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, wherein the second mask plate is a grating with a first spacing.

[0063] As can be seen from the above, the structural color film is obtained by irradiating the diacetylene layer 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 is in a microarray structure. Due to the diffraction effect and scattering effect of the microarray structure, the fluorescence intensity of the perovskite film through the structural color film will be affected by the diffraction effect and scattering effect, and the diffraction effect and scattering effect of the structural color film are related to the depth of its array structure. Therefore, for the preparation method provided by the present application to obtain an anti-counterfeiting label, the graphic display of the perovskite film can be controlled by changing the array structure depth of the structural color film, and the graphic of the perovskite film can be selectively hidden or displayed. In addition, the microarray structure depth of the structural color film can also affect the graphic display and hiding of the structural color film, so that the graphic display and hiding of the structural color film can also be controlled by changing the array structure depth of the structural color film. It can be seen from this that the anti-counterfeiting label obtained by the preparation method provided by the present application can selectively hide and display encrypted information, which helps to achieve selective decryption and decoding of information, and then helps to achieve more advanced information encryption and decoding, and provides a feasible solution for advanced anti-counterfeiting and information encryption, with important application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0065] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0066] Figure 1 A flowchart of a method for preparing an anti-counterfeiting label provided in this application;

[0067] Figure 2 A structural diagram of an anti-counterfeiting label provided for this application;

[0068] Figure 3 A flow chart of another method for preparing an anti-counterfeiting label provided in this application;

[0069] Figure 4 A flowchart of another method for preparing an anti-counterfeiting label provided in this application;

[0070] Figure 5~Figure 14 Schematic diagram of the luminescence of the anti-counterfeiting label prepared for this application in different application scenarios. DETAILED DESCRIPTION

[0071] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the embodiments in the present application. Obviously, the described embodiments are only embodiments of one area of ​​the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0072] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0073] As described in the background technology section, dual-mode and multi-mode anti-counterfeiting technologies play an important role in improving information security and anti-counterfeiting levels, and therefore have become a research focus for those skilled in the art.

[0074] The current limitations of dual-mode or multi-mode are that different optical modes interfere with each other, and the anti-counterfeiting pattern cannot be tuned, which is not conducive to the development of multi-mode anti-counterfeiting technology. The above dual-mode refers to the combination of different optical modes, such as structural color and fluorescence, while 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 are often strongly interfered with each other during manufacturing and use, especially during dynamic adjustment. In addition, traditional dual-mode and multi-mode cannot independently modulate structural color and fluorescence (CPL) information.

[0076] Based on the above, if Figure 1 As shown, Figure 1 A flowchart of a method for preparing an anti-counterfeiting label provided in the present application, the preparation method comprising:

[0077] S1: Provide a substrate 100, such as Figure 2 As shown, Figure 2 It is a schematic diagram of the structure of the anti-counterfeiting label obtained by the above preparation method. It should be noted that the substrate 100 can be a glass sheet, a quartz sheet, and a transparent polymer such as PVA, PET and other flexible substrates.

[0078] S2: A first anti-counterfeiting structure 200 and a second anti-counterfeiting structure 300 are sequentially formed in a stacked arrangement on the surface of the substrate 100 . Specifically, the first anti-counterfeiting structure 200 is located on the surface of the substrate 100 , and the second anti-counterfeiting structure 300 is located on the side of the first anti-counterfeiting structure 200 away from the surface of the substrate 100 .

[0079] For the above step S2, if Figure 3 As shown, Figure 3 This is a flow chart of a method for preparing an anti-counterfeiting label provided in the present application. Forming a first anti-counterfeiting structure 200 includes:

[0080] S21: A perovskite film 210 is formed on the surface of the substrate 100, wherein 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 present the first preset pattern. Specifically, the perovskite film 210 can be excited by the first light beam to emit fluorescence, and when the perovskite film 210 is excited by the first light beam to emit light, the first preset pattern can be observed.

[0081] Forming the second anti-counterfeiting structure 300 includes:

[0082] S22: A structural color film 310 is formed on the side of the perovskite film 210 facing 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 present a second preset pattern. Specifically, the structural color film 310 can be irradiated by the second light beam to produce color, and when the structural color film 310 is irradiated by the second light beam to produce color, the second preset pattern can be observed.

[0083] Among them, for step S22, if Figure 4 As shown, Figure 4The flowchart of a method for preparing an anti-counterfeiting label provided in the present application, wherein forming a structural color film 310 on a side of a perovskite film 210 facing away from a substrate 100 comprises:

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

[0085]

[0086] S222: A first mask plate and a second mask plate are sequentially placed on the surface of the substrate 100, and the irradiation light sequentially irradiates the diacetylene layer through the first mask plate and the second mask plate to form a structural color film 310. It should be noted that the irradiation light can be purple light, but this application does not limit this, and it depends on the specific situation.

[0087] S223: dripping acetonitrile into the structural color film 310, and treating the structural color film 310 with acetonitrile, specifically dripping acetonitrile into the structural color film 310, and then removing the acetonitrile according to actual needs. It should be noted that when dripping acetonitrile 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 of the 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 subsequent pitch of the grating mask plate.

[0089] As is known from the above, the structural color film 310 is obtained by irradiating the diacetylene layer 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 is in a microarray structure. Since the microarray structure has a diffraction effect and a scattering effect, when the perovskite film 210 is excited to emit light, its fluorescence intensity passing through the structural color film 310 will be affected by the diffraction effect and the scattering effect. Specifically, the stronger the diffraction effect and the scattering effect, the lower the fluorescence intensity after passing through the structural color film 310, and vice versa. The diffraction effect and the scattering effect of the structural color film 310 are related to the depth of its array structure. Therefore, for the anti-counterfeiting label prepared by the preparation method provided in the present application, the graphic display of the perovskite film 210 can be controlled by changing the array structure depth of the structural color film 310. Specifically, the graphic display and hiding of the perovskite film 210 can be controlled by changing the array structure depth of the structural color film 310, and the graphic 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 graphic display and hiding of the structural color film 310, that is, the graphic 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. It can be seen that the anti-counterfeiting label prepared by the preparation method provided by the present application can selectively hide and display encrypted information, which helps to achieve selective decryption and decoding of information, and further helps to achieve more advanced information encryption and decoding, providing a feasible solution for advanced anti-counterfeiting and information encryption, and has important application prospects.

[0090] When acetonitrile is added to the structural color film 310, the acetonitrile will fill the microarray structure of the structural color film 310, so that the depth of the microarray structure is reduced, and then the diffraction effect and scattering effect intensity of the microarray structure of the structural color film 310 are reduced, and the pattern of the perovskite film 210 can be displayed. After the acetonitrile is removed, the microarray structure is restored, the diffraction effect and scattering effect intensity are enhanced, and the pattern of the perovskite film 210 can be hidden, and then the pattern display and hiding of the perovskite film 210 can be selectively realized. 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, because the array structure is filled, the pattern of the structural color film 310 will be hidden. When the acetonitrile is removed, the array structure reappears, and the pattern of the structural color film 310 will be displayed again, thereby realizing the display and hiding of the pattern of the structural color film 310. When acetonitrile is added to the structural color film 310, acetonitrile can be used as an eluent to remove unpolymerized diacetylene monomers. That is to say, adding acetonitrile to the structural color film 310 can be a process step in the preparation process. In other words, the graphic display and hiding of the perovskite film 210 and the structural color film 310 can be achieved using the process steps 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 depth of the microarray structure of the structural color film 310 is shallow, its array structure can be filled with acetonitrile and the structural color pattern can be hidden. If the depth of the microarray structure 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 the subsequent embodiments.

[0092] Based on the above embodiments, in one embodiment of the present application, forming a structural color film 310 on the side of the perovskite film 210 facing away from the substrate 100 further includes:

[0093] The diacetylene layer is irradiated by irradiation light through the back side of the substrate 100 to form a structural color film 310, wherein the back side of the substrate 100 is opposite to the surface. It should be noted that the irradiation light may be ultraviolet light, but this application does not limit this, and it depends on the specific situation.

[0094] Specifically, after the irradiation light irradiates the diacetylene layer through the first mask plate and the second mask plate, the light source of the irradiation light is moved to the back side of the substrate 100 to irradiate the diacetylene layer through the back side of the substrate 100 to form the structural color film 310. Since the irradiation light directly irradiates the diacetylene layer through the back side of the substrate 100, the thickness of the microarray structure of the structural color film 310 formed after the irradiation light is 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 thus the display and hiding of the structural color film 310 can be more easily realized.

[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, thereby reducing the influence of the structural color film 310 on the graphic display of the perovskite film 210, and effectively solving the mutual interference between different optical modes.

[0096] Based on the foregoing embodiments, in one embodiment of the present application, Figure 5As shown, the second preset pattern includes a 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 a first portion 3111 and a second portion 3112 arranged in sequence along a first direction, and the corresponding second mask plate includes a first mask area, and the mask pattern of the first mask area is the same shape as the first sub-pattern 311. Among them, 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 sequentially irradiates the diacetylene layer through the first mask plate and the second mask plate to form the structural color film 310, including:

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

[0098] Afterwards, the irradiation light irradiates the second portion through the back side of the substrate 100, that is, the irradiation light irradiates the second portion of the first sub-pattern through the back side of the substrate 100, forming the structural color film 310, so that the depth of the microarray structure of the second portion 3112 of the first sub-pattern 311 is smaller than the depth of the microarray structure of the first portion of the first sub-pattern 311, as shown in FIG. Figure 5 The enlarged images of area 1 and area 2 are shown in FIG.

[0099] Based on the above, continue as Figure 5 As shown, if the incident direction of the second light beam is perpendicular to the first direction, Figure 5 As shown by the white arrow in the middle, 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 pointing to acetonitrile being 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, while the second part 3112 of the first sub-pattern 311 is hidden, and 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 display of each part of the first sub-pattern 311.

[0100] Based on the above embodiment, in one embodiment of the present application, continue as follows Figure 5As shown, the second preset pattern also includes a second sub-pattern 312, that is, the pattern of the structural color film 310 also includes a second sub-pattern 312, the first sub-pattern 311 and the second sub-pattern 312 are arranged along the second direction, and the second sub-pattern 312 includes a third portion 3121 and a fourth portion 3122 arranged along the first direction. Correspondingly, the second mask plate includes a second mask area, the mask pattern of the second mask area is the same shape as the second sub-pattern 312, the second direction is parallel to the plane where the structural color film 310 is located, and is parallel to the periodic direction of the second mask area, that is, parallel to the arrangement direction of the periodic structure of the second mask area, and the second direction is perpendicular to the first direction. Based on this, the irradiation light sequentially irradiates the diacetylene layer through the first mask plate and the second mask plate 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] Afterwards, the irradiation light irradiates the second portion 3112 and the fourth portion 3122 through the back side of the substrate 100 to form the structural color film 310, that is, the irradiation light irradiates the second portion 3112 of the first sub-pattern 311 and the fourth portion 3122 of the second sub-pattern 312 through the back side of the substrate 100, so that for the first sub-pattern 311, the thickness of the microarray structure of the second portion 3112 is less than the thickness of the microarray structure of the first portion 3111, and similarly, for the second sub-pattern 312, the thickness of the microarray structure of the fourth portion 3122 is less than the thickness of the microarray structure of the third portion 3121, as shown in FIG. Figure 5 The enlarged images of regions 3 and 4 are shown in FIG.

[0103] Based on the above, if Figure 5 As shown, 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 a second sub-graph 312; if the incident direction of the second light beam is perpendicular to the second direction and the structural color film 310 is treated with acetonitrile, the structural color film 310 can be irradiated by the second light beam to present a third part 3122 of the second sub-graph 312; after removing the acetonitrile, the structural color film 310 can be irradiated by the second light beam again to present the second sub-graph 312, thereby realizing the selective hiding and display of each part of the second sub-graph 312.

[0104] Based on the above, it can be known that the display and hiding of the structural color film 310 pattern no longer depends solely on the incident direction of the second light beam, but can also be achieved based on acetonitrile treatment. Therefore, the anti-counterfeiting label prepared by this preparation method has multiple stimulus response mechanisms, which is conducive to the development of multi-mode anti-counterfeiting labels.

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

[0106] A third mask is placed above the surface of the substrate 100 , and the third mask is located between the first mask and the second mask. The irradiation light sequentially passes through the first mask, the third mask, and the second mask to irradiate the diacetylene layer to form a structural color film 310 .

[0107] 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 the second pitch, and the second pitch is greater than the first pitch.

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

[0109] A fourth mask is placed on the back of the substrate 100, and the diacetylene layer is irradiated with irradiation light through the fourth mask and the substrate 100 in sequence to form a structural color film 310. Among them, the fourth mask is a grating of the third spacing, and the third spacing is equal to the second spacing. It should be noted that the fourth mask can be the same grating as the third mask, that is, the fourth mask can be reused as the third mask, but this application is not limited to this, depending on the specific circumstances. It should also be noted that the value range of the first spacing can be 300nm~10μm, including the endpoint values, and the value range of the second spacing and the third spacing can be 300nm~10μm, including the endpoint values.

[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 spacing of the second mask is 1 μm, and the slit spacing of the third mask is 60 μm. 2,4-hexadiyne-1,6-diacrylate solution and photoinitiator (2-hydroxy-2-methyl propylene ketone) are mixed in a ratio of 9:1 (v / v) to form diacetylene liquid (abbreviated as HD-DA), 3 μL of HD-DA is dripped on the side of the perovskite film 310 away from the substrate 100, and ultraviolet light passes through the first mask ( Figure 6 The HD-DA solution is irradiated with a first mask plate and a 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, such as Figure 6 As shown in a. Ultraviolet light is irradiated to the HD-DA solution through the first mask plate and the second mask plate for 1 minute, and then the light source is moved to the back of the substrate 100, and ultraviolet light is irradiated through the back of the substrate 100 for 2 minutes, and the first mask plate and the second mask plate are removed, and acetonitrile is used as an eluent to remove the unpolymerized HD-DA, and a structural color film ii is obtained, as shown in Figure 6As shown in b. The ultraviolet light is sequentially irradiated through the first mask plate, the third mask plate Grating2 and the second mask plate Grating1 to irradiate the diacetylene layer for 10 min, the first mask plate, the second mask plate and the third mask plate are removed, and acetonitrile is used as an eluent to remove the unpolymerized HD-DA to obtain a structural color film iii, as shown in Figure 6 As shown in c. The ultraviolet light sequentially passes through the first mask plate, Grating2 and the second mask plate Grating1 to irradiate the diacetylene layer for 2 minutes, then the light source and Grating2 are moved to the back of the substrate 100, and the ultraviolet light sequentially passes through the third mask plate and the substrate 100 to irradiate the diacetylene layer for 6 minutes, and then the light source, the first mask plate, the second mask plate and the third mask plate are removed, and acetonitrile is used as an eluent to remove the unpolymerized HD-DA to obtain a structural color film iv, as shown in FIG. Figure 6 As shown in middle d.

[0111] Based on the above, if Figure 7 and Figure 8 As shown, Figure 7 A is the graphic display of the first preset graphic corresponding to the structural color film i before and after acetonitrile and after acetonitrile is removed, B is the graphic display of the first preset graphic corresponding to the structural color film ii before and after acetonitrile and after acetonitrile is removed, C is the graphic display of the first preset graphic corresponding to the structural color film iii before and after acetonitrile and after acetonitrile is removed, D is the graphic display of the first preset graphic corresponding to the structural color film iv before and after acetonitrile and after acetonitrile is removed, Figure 8 a is the graphic display of the second preset graphic corresponding to the structural color film i before and after acetonitrile and after acetonitrile is removed, b is the graphic display of the second preset graphic corresponding to the structural color film ii before and after acetonitrile and after acetonitrile is removed, c is the graphic display of the second preset graphic corresponding to the structural color film iii before and after acetonitrile and after acetonitrile is removed, and d is the graphic display of the second preset graphic A corresponding to the structural color film iv before and after acetonitrile and after acetonitrile is removed. According to Figure 7 It can be seen that based on the depth of the microarray structure of the structural color film 310, in combination 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 achieved.

[0112] according to Figure 7 and Figure 8It can be seen that when the structural color film 310 is the structural color film i, the array depth of the structural color film 310 is large, and it has strong diffraction effect and scattering effect, resulting in a low fluorescence intensity of the perovskite film 210. After being treated with acetonitrile, the fluorescence intensity of the perovskite film 210 is increased, but after the acetonitrile is removed, the fluorescence intensity will decrease again. Therefore, if the 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 the structural color film ii, the array depth of the structural color film 310 is small, and the diffraction effect and scattering effect are weak, which will not affect the fluorescence intensity of the perovskite film 210. Therefore, if the 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 the structural color film iii, after the acetonitrile treatment, the graphics of the structural color film 310 and the perovskite film 210 are displayed. After the acetonitrile is removed, the graphics of the structural color film 310 are hidden, and the fluorescence intensity of the perovskite film 210 is also greatly reduced. Therefore, if the 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 at the same time. When the structural color film 310 is the structural color film iv, the graphics of the structural color film 310 can be hidden, and the graphics display of the perovskite film 210 is not affected by the acetonitrile treatment before and after.

[0113] Based on the above, the anti-counterfeiting label prepared by the improved preparation method of the present application has multiple optical modes, which 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 to achieve a higher level of security information encryption and decryption.

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

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

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

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

[0118] Specifically, in one embodiment of the present application, Fig. 9 As shown, the third sub-pattern 313 is a panda, and the fourth sub-pattern 314 is an elephant. A 2,4-hexadiyne-1,6-diacrylate solution is mixed with a photoinitiator (2-hydroxy-2-methyl propylene ketone) at a ratio of 9:1 (v / v) to form a diacetylene liquid, which is then dripped onto the surface of the substrate 100. Ultraviolet light is irradiated to the HD-DA solution for 10 minutes through the first sub-mask plate 11 with a panda pattern and the second mask plate with a spacing of 1 μm. Then the second mask plate is rotated 90 degrees along its mounting surface. o , and the first sub-mask 11 is replaced by the second sub-mask 12 with the mask pattern of an elephant, and the ultraviolet light is sequentially irradiated through the second sub-mask 12 and the second mask to irradiate the HD-DA solution for 10 min. All mask plates are removed, and acetonitrile is used as an eluent to remove the unpolymerized HD-DA, and a structural color film 310 with a specific periodic structure is obtained. Based on the above structural color film 310, when the observation distance changes from far to near, for example, from the observation distance L1=60cm to the observation distance L2=35cm, and then to the observation distance L3=15cm, it can be observed that the panda pattern on the structural color film 310 first changes color, and then changes from the panda pattern to the elephant pattern. It should be noted that when the incident angle of the second light beam remains unchanged, the pattern display of the structural color film 310 is also related to the observation angle, that is, it is related to the observation distance. Therefore, when the observation distance changes from far to near, it can be observed that the panda pattern on the structural color film 310 first changes color, and then changes from the panda pattern to the elephant pattern.

[0119] In another embodiment of the present application, Fig.10As shown, the third sub-pattern 313 is a QR code, and the fourth sub-pattern 314 is the text "Made in China". 2,4-hexadiyne-1,6-diacrylate solution and photoinitiator (2-hydroxy-2-methyl propylene ketone) are mixed in a ratio of 9:1 (v / v) to form diacetylene liquid, which is then dripped onto the surface of the substrate 100. Ultraviolet light is irradiated to the HD-DA solution for 2 minutes through the first sub-mask plate 11 with a mask pattern of a QR code and the second mask plate with a spacing of 1 μm. Then the second mask plate is rotated 90 degrees along its mounting surface. o The first sub-mask 11 is replaced with the second sub-mask 12 whose mask pattern is the text "Made in China". Ultraviolet light is sequentially irradiated through the second sub-mask 12 and the second mask for 2 min. All masks are removed, and acetonitrile is used as an eluent to remove the unpolymerized HD-DA, thereby obtaining a structural color film 310 with a specific periodic structure. Based on the above structural color film 310, when the incident direction of the second light beam changes from perpendicular to the fourth direction to parallel to the fourth direction, it can be observed that the pattern on the structural color film 310 changes from a QR code to text.

[0120] It can be seen from the above that the anti-counterfeiting label prepared by the preparation method can realize the selective display and hiding of different structural color patterns, and the hiding and display of the above structural color patterns are reversible, which is highly practical. It should be noted that the present application does not limit the ultraviolet light irradiation time of different steps in the preparation process of different structural color patterns, which depends on the specific situation.

[0121] Based on the above embodiments, in one embodiment of the present application, forming a perovskite film 210 on the surface of the substrate 100 includes:

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

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

[0124] Specifically, a CsPbCl3 perovskite nanocrystal n-hexane solution is added to a mixture of Sylgard 184 silicone elastomer to form a perovskite mixture, a fluorescent pattern of a first preset pattern is prepared by inkjet printing technology, and the pattern is fixed by vacuum drying at 60°C for 3 hours to form a perovskite film. It should be noted that in other embodiments of the present application, a fluorescent pattern of a first preset pattern can also be prepared by screen printing, spraying or dot mapping to obtain a perovskite film 210, which is not limited in the present application and depends on the specific circumstances.

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

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

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

[0128] A first silver nanowire layer 221 is formed on the side of the perovskite film 210 facing 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 range from -90° to 90°, which can be determined according to the specific situation.

[0130] Specifically, depositing a twisted stacked silver nanowire layer (AgNWs for short) on the side of the perovskite film 210 away from the substrate 100 includes: depositing a first silver nanowire layer 221, specifically taking 3 ml of AgNWs solution, dripping it to the center of the surface of the ethylene glycol-filled container (with a diameter of 15 cm), and the injection rate is 20 ml / h. After the injection is completed, a hexadecyltrimethylammonium chloride aqueous solution (CTAC for short) is immediately dripped into the center of the container to induce the AgNWs to align 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 the subsequent deposition of the second silver nanowire layer 222, the substrate 100 is rotated clockwise or counterclockwise at a pre-designed angle, and then the perovskite film 210 is rotated, and then the second silver nanolayer 222 is deposited to obtain a twisted stacked silver nanowire layer 220. It should be noted that the deposition of the above-mentioned silver nanowire layer 220 can be achieved by LB film method, immersion and pulling method, etc., but this application is not limited to this, and it depends on the specific situation. In one embodiment of the present application, the CTAC may be specifically 100 mM or 3 mL, but the present application does not limit this, and it depends on the specific situation.

[0131] Based on the above, in a 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 maximized and opposite, and then when the perovskite film 210 is observed 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, Fig.11 As shown, the perovskite film is a CsPbBr3 perovskite film, and the first preset pattern includes a fifth sub-pattern 211 and a sixth sub-pattern 212. If the perovskite film 210 is observed using a left-handed circular polarizer (L-CPF), the fifth sub-pattern 211 is blue, and if the perovskite film 210 is observed using a right-handed circular polarizer (R-CPF), the sixth sub-pattern 212 is red. The fifth sub-pattern 211 and the sixth sub-pattern 212 can be directly observed by naked eyes. Since the first angle is 45° and the second angle is -45°, the first silver nanowire layer 221 and the second silver nanowire layer 222 have opposite chirality, so when the perovskite film 210 is observed through the silver nanowire layer 220 using a left-handed circular polarizer and a right-handed circular polarizer, a fifth sub-pattern 211 appears blue when the perovskite film 210 is observed through the silver nanowire layer 220 using a left-handed circular polarizer, and a sixth sub-pattern 212 appears red when the perovskite film 210 is observed through the silver nanowire layer 220 using a right-handed circular polarizer.

[0133] In addition, in this embodiment, the perovskite film is a CsPbBr3 perovskite film. If the first anti-counterfeiting structure 200 is treated with HCl, the fluorescence wavelength of the perovskite film 210 is blue-shifted. If the first anti-counterfeiting 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. Fig.12 As shown, Fig.12 In the figure, a and b are the fluorescence color changes of the perovskite film 210 under white light and ultraviolet light excitation during the halogen anion exchange process. It can be seen that the chiral characteristics of the fluorescence pattern of the anti-counterfeiting label prepared by the preparation method can also be dynamically modulated by halogen anion exchange, that is, the fluorescence color of the perovskite film 210 can be specifically regulated by halogen anion exchange, and at the same time, the opposite chiral characteristics can be presented in the red fluorescence and blue fluorescence ranges, which is conducive to the application of multi-mode anti-counterfeiting labels in the field of high-level anti-counterfeiting.

[0134] Based on the above, in a specific embodiment of the present application, a CsPbCl3 perovskite nanocrystal n-hexane solution is added to a mixture of Sylgard 184 silicone elastomer to form a perovskite mixture, and a fluorescent pattern of a first preset pattern is prepared by inkjet printing technology, and the first preset pattern is a butterfly, and is fixed by vacuum drying at 60°C for 3 hours to form a perovskite film with a butterfly pattern. Afterwards, a twisted stacked silver nanowire layer 220 is deposited on the surface of the above perovskite film 210. Continue as Fig.11 When the perovskite film 210 is observed through a left-handed circular polarizer and a right-handed circular polarizer, the blue left half of the wing and the red right half of the wing can be observed respectively, and the entire butterfly pattern can be observed with the naked eye.

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

[0136] Embodiment 1: Fig.13 As shown, Fig.13In the structure “ii”, the structure “ii” represents the structural color film, the CPL layer represents the perovskite film, the SC represents the structural color pattern, the FL represents the fluorescent pattern, and the CPL represents the fluorescent chiral pattern. The perovskite mixture of the CsPbBr3 perovskite nanocrystal n-hexane solution and the organosilicon elastic crystal PDMS was prepared into a chameleon fluorescent pattern by inkjet printing technology, and vacuum dried at 60 ° C for 3 h to form a perovskite film 210, and the first preset pattern was a chameleon. Then, a twisted stacked silver nanowire layer 220 was deposited on the surface of the perovskite film 210. A polyethylene film 230 was deposited on the surface of the silver nanowire layer 220 and subjected to plasma treatment (60 mW, 10 min). The 2,4-hexadiyne-1,6-diacrylate (HD-DA) solution was mixed with a photoinitiator (2-hydroxy-2-methylpropenone) in a ratio of 9:1 (v / v) to form a diacetylene liquid. 3 μL of diacetylene liquid is dripped onto the surface of the silver nanowire layer 220 to form a diacetylene layer. Ultraviolet light passes through the first sub-mask plate and the second sub-mask plate to irradiate the diacetylene layer for 30 seconds, and then the light source and the first sub-mask plate are moved to the back of the substrate 100. The ultraviolet light passes through the first sub-mask plate and passes through the back of the substrate 100 to irradiate the diacetylene layer for 2 minutes. The mask pattern of the first sub-mask plate is a "window grille", the spacing of the second mask plate is a grating of 1 μm, and the first sub-mask plate is located on the back of the substrate 100 and is mirrored relative to the first sub-mask plate located on the front of the substrate 100. After that, the second mask plate is rotated 90° along its mounting surface, and the light source is moved to the surface of the substrate 100. The ultraviolet light passes through the second sub-mask plate and the second mask plate to irradiate the diacetylene layer for 30 seconds, and then the light source and the second sub-mask plate are moved to the back of the substrate 100. The ultraviolet light passes through the second sub-mask plate and passes through the back of the substrate 100 to irradiate the diacetylene layer for 2 minutes. The mask pattern of the second sub-mask is a flower, and the second sub-mask located on the back of the substrate 100 is a mirror image relative to the second sub-mask located on the front of the substrate 100. Finally, all the masks are removed, and acetonitrile is used as an eluent to remove the unpolymerized polydiacetylene to obtain a structural color film 310 with a composite pattern.

[0137] Based on the above, the microarray structure of the composite pattern structural color film 310 is the same as the microarray structure of the aforementioned structural color film ii, so that the composite pattern structural color film 310 can change the structural color pattern from a "window paper-cut" pattern to a "flower" pattern by changing the incident direction of the second light beam under white light, and the structural color pattern is hidden after washing with acetonitrile, and will not affect the fluorescence pattern and chiral characteristics of the underlying perovskite film 210. Similarly, the fluorescence pattern and 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 Fig.13It is also known that if the chameleon fluorescence pattern is treated with HI, a blue chameleon pattern can be seen when observed with a left-handed circular polarizer, while no pattern is observed when observed with 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 fluorescence pattern is treated with HCl, a red chameleon pattern can be seen when observed with a right-handed circular polarizer, while no pattern is observed when observed with a right-handed circular polarizer, and the red chameleon pattern can be seen with the naked eye.

[0139] Example 2: As Fig.14 shown, SC represents the structural color pattern, FL represents the fluorescence pattern on the back of the substrate 100, and CPL represents the fluorescent chiral pattern on the back of the substrate 100. Specifically, a hexane solution of CsPbBr3 perovskite nanocrystals and a perovskite mixture of polydimethylsiloxane (PDMS) of organosilicon elastomers are used to prepare a fluorescent pattern of the Chinese character "Ke" through an inkjet printing technique, and vacuum-dried 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 diacetylene liquid is formed by mixing a solution of 2,4-hexadiyne-1,6-diacrylate (HD-DA) and a photoinitiator (2-hydroxy-2-methylpropiophenone) in a ratio of 9:1 (v / v). 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 sequence 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. All mask plates are removed, and acetonitrile is used as an eluent to remove the unpolymerized polydiacetylene to obtain the structural color thin film 310 with a rabbit pattern. The special feature of this embodiment 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 this embodiment, when the surface of the structural color film 310 is in a state of acetonitrile infiltration, the rabbit pattern in the structural color mode and the Chinese character "Science" in the fluorescence mode will both appear. The perovskite film on the back of the substrate 100 can change from blue to red after being treated with HI, and the above color change process can also be reversibly changed by using HCl treatment. In addition, in the fluorescence mode, the Chinese characters "He" and "Dou" can be observed separately by using left / right circular polarizers. It should be noted that since CsPbCl3 and CsPbI3 have fluorescence signals with exactly opposite signs, the disappearance and appearance of the Chinese characters "He" and "Dou" are exactly opposite in order. And due to the small asymmetry factor Glum of CsPbBr3, only the Chinese character "Science" can always be obtained when observing the perovskite film with left / right circular polarizers.

[0141] Based on the above embodiments, it can be seen that the anti-counterfeiting label prepared in this application combines a multi-mode dynamic label with adjustable structural color, fluorescence, and CPL information, and has great potential in the field of high-order anti-counterfeiting. And during the dynamic adjustment process of the anti-counterfeiting label, through the microarray structure of the upper structural color film, the adjustable structural color, fluorescence, and CPL information can selectively achieve the regulation of the interference mode and the orthogonal mode, and has great potential in the field of high-order anti-counterfeiting.

[0142] This application also provides an anti-counterfeiting label, as Figure 2 shown, the anti-counterfeiting label includes:

[0143] A substrate 100.

[0144] A first anti-counterfeiting structure 200 and a second anti-counterfeiting structure 300 that are sequentially stacked on the surface of the substrate 100. The first anti-counterfeiting structure 200 includes 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 a first preset pattern. The second anti-counterfeiting structure 300 includes a structural color film 310 formed on the side of the perovskite film 210背离 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 a second preset pattern.

[0145] Among them, the structural color film 310 is formed by irradiating light through a first mask plate and a 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 grating with a first pitch.

[0146] As is 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 is in a microarray structure. Since the microarray structure has diffraction effect and scattering effect, when the perovskite film 210 is excited to emit light, its fluorescence intensity passing through the structural color film 310 will be affected by the diffraction effect and scattering effect. Specifically, the stronger the diffraction effect and scattering effect, the lower the fluorescence intensity after passing through the structural color film 310, and vice versa. The diffraction effect and scattering effect of the structural color film 310 are related to the depth of its array structure. Therefore, for the anti-counterfeiting label provided in the present application, the graphic display of the perovskite film 210 can be controlled by changing the array structure depth of the structural color film 310. Specifically, the graphic display and hiding of the perovskite film 210 can be controlled by changing the array structure depth of the structural color film 310, and the graphic 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 graphic display and hiding of the structural color film 310, that is, the graphic 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. It can be seen that the anti-counterfeiting label provided by the present application can selectively hide and display encrypted information, which helps to achieve selective decryption and decoding of information, and further helps to achieve more advanced information encryption and decoding, providing a feasible solution for advanced anti-counterfeiting and information encryption, and has important application prospects.

[0147] Based on the above embodiments, in one embodiment of the present application, the first anti-counterfeiting structure 200 further includes:

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

[0150] Based on the above, in a 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 maximized and opposite, and then when the perovskite film 210 is observed 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.

[0151] In summary, the present application provides a method for preparing an anti-counterfeiting label and an anti-counterfeiting label, the preparation method comprising: forming a first anti-counterfeiting structure and a second anti-counterfeiting structure arranged in layers on the surface of a substrate in sequence, forming the first anti-counterfeiting structure comprising forming a perovskite film on the surface of the substrate, the perovskite film being able to be irradiated by a first light beam to present a first preset pattern, forming the second anti-counterfeiting structure comprising forming a structural color film on the side of the perovskite film away from the substrate, the structural color film being able to be irradiated by a second light beam to present a second preset pattern. Forming a 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 through a first mask plate and a second mask plate in sequence to form a 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, wherein the second mask plate is a grating with a first spacing.

[0152] As can be seen from the above, the structural color film is obtained by irradiating the diacetylene layer 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 is in a microarray structure. Due to the diffraction effect and scattering effect of the microarray structure, the fluorescence intensity of the perovskite film through the structural color film will be affected by the diffraction effect and scattering effect, and the diffraction effect and scattering effect of the structural color film are related to the depth of its array structure. Therefore, for the preparation method provided by the present application to obtain an anti-counterfeiting label, the graphic display of the perovskite film can be controlled by changing the array structure depth of the structural color film, and the graphic of the perovskite film can be selectively hidden or displayed. In addition, the microarray structure depth of the structural color film can also affect the graphic display and hiding of the structural color film, so that the graphic display and hiding of the structural color film can also be controlled by changing the array structure depth of the structural color film. It can be seen from this that the anti-counterfeiting label obtained by the preparation method provided by the present application can selectively hide and display encrypted information, which helps to achieve selective decryption and decoding of information, and then helps to achieve more advanced information encryption and decoding, and provides a feasible solution for advanced anti-counterfeiting and information encryption, with important application prospects.

[0153] In this specification, each embodiment is described in a progressive, parallel, or progressive and parallel manner. Each embodiment focuses on the differences from other embodiments, and the same or similar areas between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method area description.

[0154] It should be noted that in the description of the present application, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0155] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0156] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be 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 the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to 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: providing a substrate; Forming a first anti-counterfeiting structure and a second anti-counterfeiting structure which are sequentially stacked on the surface of the substrate; The forming of the first anti-counterfeiting structure comprises: Forming a perovskite film on the surface of the substrate, wherein the shape of the perovskite film is a first preset pattern, and the perovskite film can be irradiated by a first light beam to form the first preset pattern; The forming of the second anti-counterfeiting structure comprises: Forming a structural color film on the side of the perovskite film away from the substrate, wherein 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 present a second preset pattern; Wherein, forming a structural color film on a side of the perovskite film away from the substrate comprises: Dropping a diacetylene liquid on a side of the perovskite film away from the substrate to form a diacetylene layer, wherein the diacetylene liquid contains a diacetylene monomer; placing a first mask plate and a second mask plate in sequence above the surface of the substrate, and irradiating light through the first mask plate and the second mask plate in sequence to irradiate the diacetylene layer to form the structural color thin film; adding acetonitrile dropwise to the structural color film to treat the structural color film with acetonitrile; The pattern of the first mask is the same as the second preset pattern, and the second mask is a grating with a first pitch.

2. The method for preparing an anti-counterfeit label according to claim 1, characterized in that: The forming of a structural color film on the side of the perovskite film away from the substrate further comprises: The irradiation light irradiates the diacetylene layer through the back side of the substrate to form the structural color film; Wherein, 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 portion and a second portion arranged along a first direction, the second mask plate includes a first mask area, the first direction is parallel to the plane where the structural color film is located, and is parallel to the periodic direction of the first mask area; The irradiation light sequentially irradiates the diacetylene layer through the first mask plate and the second mask plate to form the structural color thin film, which includes: The irradiation light sequentially irradiates the diacetylene layer through the first mask plate and the first mask area; Afterwards, irradiating light irradiates the second portion through the back side of the substrate to form the structural color film; Among them, if 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; if 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 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 portion and a fourth portion 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 is parallel to the periodic direction of the second mask area, and the second direction is perpendicular to the first direction; The irradiation light sequentially irradiates the diacetylene layer through the first mask plate and the second mask plate to form the structural color thin film, which includes: After the irradiation light passes through the first mask plate, it irradiates the diacetylene layer through the first mask area and the second mask area; Afterwards, irradiating light irradiates the second portion and the fourth portion through the back side of the substrate to form the structural color film; Among them, 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 with acetonitrile, the structural color film can be irradiated by the second light beam to present the third part of the second sub-pattern.

5. The method for preparing an anti-counterfeit label according to claim 1, characterized in that: The forming of a structural color film on the side of the perovskite film away from the substrate further comprises: A third mask is placed above the surface of the substrate, the third mask is located between the first mask and the second mask, and the irradiation light passes through the first mask, the third mask and the second mask in sequence to irradiate the diacetylene layer to form the structural color thin film; The third mask is a grating with a second pitch, and the second pitch is greater than the first pitch.

6. The method for preparing the anti-counterfeiting label according to claim 5, characterized in that: The forming of a structural color film on the side of the perovskite film away from the substrate further comprises: placing a fourth mask plate on the back of the substrate, and irradiating the diacetylene layer through the fourth mask plate and the substrate in sequence with irradiation light to form the structural color thin film; The fourth mask plate is a grating with a third pitch, and the third pitch is equal to the second pitch.

7. The method for preparing an anti-counterfeit 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 plate includes 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 first mask plate and the second mask plate are sequentially placed above the surface of the substrate, and the irradiation light sequentially passes through the first mask plate and the second mask plate to irradiate the diacetylene layer, and forming the structural color film includes: The first sub-mask plate and the second mask plate are sequentially placed above the surface of the substrate, and the irradiation light sequentially irradiates the diacetylene layer through the first sub-mask plate and the second mask plate; The second mask plate is rotated 90 degrees along the third direction, and a second sub-mask plate is placed above the second mask plate, and the irradiation light sequentially passes through the second sub-mask plate and the second mask plate to irradiate the diacetylene layer to form the structural color thin film; wherein the third direction is parallel to the mounting surface of the second mask plate; If the incident direction of the second light beam is perpendicular to the fourth direction, and the fourth direction is parallel to the periodic direction of the second mask before rotation, 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.

8. The method for preparing an anti-counterfeit label according to claim 1, characterized in that: The forming of a perovskite film on the surface of the substrate comprises: adding a n-hexane solution of CsPbX3 perovskite nanocrystals to a silicone elastomer to form a perovskite mixture; Applying the perovskite mixture in the first preset pattern on the surface of the substrate to form the perovskite film; Wherein, the perovskite film is a CsPbX3 perovskite film, and X is Br, Cl or I.

9. The method for preparing an anti-counterfeit label according to claim 8, characterized in that: The forming of the first anti-counterfeiting structure further comprises: forming a silver nanowire layer on a side of the perovskite film facing away from the substrate; The forming of a silver nanowire layer on the side of the perovskite film facing away from the substrate comprises: forming a first silver nanowire layer on a side of the perovskite film facing away from the substrate, wherein the first silver nanowire layer is oriented at a first angle; forming a second silver nanowire layer on a side of the first silver nanowire layer away from the substrate, wherein the second silver nanowire layer is oriented at a second angle; Wherein, the first angle and the second angle are different.

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

11. The method for preparing an anti-counterfeit 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; When the perovskite film is observed using a left-handed circular polarizer, the fifth sub-pattern appears blue, and when the perovskite film is observed using a right-handed circular polarizer, the sixth sub-pattern appears red; If the first anti-counterfeiting structure is treated with HCl, the fluorescence wavelength of the perovskite film is blue-shifted; if the first anti-counterfeiting structure is treated with HI, the fluorescence wavelength of the perovskite film is red-shifted.

12. An anti-counterfeiting label, characterized in that: include: substrate; A first anti-counterfeiting structure and a second anti-counterfeiting structure are sequentially stacked and arranged on the surface of the substrate; The first anti-counterfeiting structure includes a perovskite film located 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 present the first preset pattern; the second anti-counterfeiting structure includes a structural color film located 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 present a second preset pattern; The structural color film is formed by irradiating light through a first mask plate and a 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 grating with a first pitch.

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 a side of the perovskite film away from the substrate, wherein the silver nanowire layer includes a first silver nanowire layer formed on a side of the perovskite film away from the substrate, and a second silver nanowire layer formed on a side of the first silver nanowire layer away from the substrate; The first silver nanowire layer is oriented at a first angle, the second silver nanowire layer is oriented at a second angle, and 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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