Temperature-sensitive dynamic grating anti-counterfeit label and preparation method thereof

Abstract

The invention relates to the technical field of anti-counterfeit labels, in particular to a temperature-sensitive dynamic grating anti-counterfeit label and a preparation method thereof, and the temperature-sensitive dynamic grating anti-counterfeit label is sequentially compounded with a gold stamping layer, a cat eye lens layer, a temperature change ink layer, a light change ink layer, a dynamic sand silver layer, a crystal relief layer, a color grating layer, a dynamic grating layer and a base material layer from top to bottom. The edge of the base material layer is provided with an anti-tearing structure, the dynamic and color grating layer is in collaborative dynamic display, the optical variable ink layer contains metal particles and can change colors in multiple colors, the temperature variable ink layer is of an irreversible thermochromic type, the cat eye lens layer forms a three-dimensional dynamic visual effect, the crystal embossment layer is embedded with micro characters, and the gilding layer shows a colorful visual effect. Multiple anti-counterfeiting elements are integrated to form a multi-level anti-counterfeiting system, and the anti-counterfeiting threshold is improved; the color development of the temperature change ink is clear, stable and irreversible, the visual identification degree is enhanced by the dynamic grating and the cat eye lens, the label reuse is avoided by the anti-tearing structure, and the anti-counterfeiting reliability is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of anti-counterfeiting labels, in particular to a temperature-sensitive dynamic grating anti-counterfeiting label and a preparation method thereof. BACKGROUND

[0002] In the current rapid development of commodity economy, counterfeit and inferior commodities are rampant in the market, not only damaging the legitimate rights and interests of consumers, but also seriously disrupting the market order and causing irreversible negative impact on the brand image of enterprises. Therefore, anti-counterfeiting labels with high security and difficult to counterfeit have become the core carrier of commodity traceability and quality assurance. At present, most anti-counterfeiting labels on the market use single or a few combinations of anti-counterfeiting technologies, such as ordinary grating anti-counterfeiting, simple optically variable ink printing, and basic relief patterns, but their anti-counterfeiting performance is limited and easy to be imitated by illegal elements.

[0003] The existing grating type anti-counterfeiting labels generally have the problems of single dynamic display effect and insufficient visual recognition, and poor compatibility with other anti-counterfeiting elements, making it difficult to form a synergistic anti-counterfeiting effect. The temperature change ink type anti-counterfeiting label often has the problems of insufficient disclosure of the formula, poor color change stability, unclear color development, unclear color change threshold, or reversible color change leading to anti-counterfeiting failure. At the same time, most anti-counterfeiting labels lack effective anti-replacement and anti-tearing design, and illegal elements can achieve counterfeiting by completely peeling off and replacing the label, further reducing the reliability of anti-counterfeiting. In addition, the preparation process of the existing composite anti-counterfeiting label has the problems of non-standard process and fuzzy parameter control, resulting in poor product consistency, unstable anti-counterfeiting effect, and inability to meet the demand for high security level anti-counterfeiting of high-end commodities.

[0004] In order to solve the above technical defects, it is urgent to develop a new type of anti-counterfeiting label which integrates multiple high-efficiency anti-counterfeiting technologies, has synergistic effect of various anti-counterfeiting elements, has clear and stable anti-counterfeiting response characteristics, and has anti-replacement and anti-tearing functions, so as to improve the security and reliability of anti-counterfeiting and effectively curb counterfeit and inferior behaviors. SUMMARY

[0005] (I) Technical problems solved In view of the deficiencies of the prior art, the present application provides a temperature-sensitive dynamic grating anti-counterfeiting label and a preparation method thereof.

[0006] (II) Technical solutions A temperature-sensitive dynamic grating anti-counterfeiting label is sequentially compounded from top to bottom by a gold stamping layer, a cat-eye lens layer, a temperature change ink layer, a light change ink layer, a dynamic sand silver layer, a crystal relief layer, a color grating layer, a dynamic grating layer and a substrate layer, the substrate layer is provided with a tear-proof structure at the edge; the dynamic grating layer and the color grating layer form a synergistic dynamic display structure, and the grating pitch is 50-200 microns; the light change ink layer contains metal particles and presents a multi-color change effect within a 0-180 degree viewing angle range; the temperature change ink layer is of an irreversible thermochromic type and is composed of a fluorane type leuco dye, a bisphenol A type color developer, an ethanol-ethyl acetate mixed solvent and an acrylic resin film forming agent; the cat-eye lens layer cooperates with the color grating layer and the dynamic grating layer to form a three-dimensional dynamic visual effect, and the lens focal length is 0.5-2.0 mm; the crystal relief layer is internally embedded with micro-text; and the gold stamping layer presents a colorful visual effect.

[0007] Preferably, the micro-text is arranged at intervals along the texture direction of the crystal relief layer, and the line width of the micro-text is 10-30 microns, the height is 5-15 microns, and the distance between adjacent micro-texts is 50-100 microns.

[0008] Preferably, the grating pitch of the dynamic grating layer is 80-150 microns, and the material is polyethylene terephthalate or polycarbonate, and the inclination angle of the grating stripes on the dynamic grating layer is 0-45 degrees.

[0009] Preferably, in the temperature change ink layer, the fluorane type leuco dye is selected from 3,3-bis(4-dimethylamino phenyl)-6-dimethylamino fluorane or 3-diethylamino-7-chlorofluorane, the bisphenol A type color developer is selected from 4,4'-dihydroxydiphenyl propane or 4,4'-dihydroxydiphenyl sulfone, and the volume ratio of ethanol to ethyl acetate in the mixed solvent is 1:1-3:1; wherein the mass fraction of the leuco dye is 5-15%, the mass fraction of the color developer is 10-20%, the mass fraction of the mixed solvent is 40-60%, and the mass fraction of the acrylic resin film forming agent is 15-30%.

[0010] Preferably, the metal particles in the light change ink layer are aluminum powder or copper powder, the particle size of the metal particles is 10-50 nm, the mass fraction is 8-25%, and different color depth changes are presented at 30, 60, 90 and 120 degrees of viewing angle, and the color difference ΔE is greater than or equal to 3.0.

[0011] Preferably, the anti-tear structure is a continuous zigzag knife line integrally formed on the substrate layer, the knife line depth is 1 / 2-3 / 4 of the substrate thickness, the continuous zigzag knife line is a closed ring or an intermittent ring, the area of the region surrounded by the closed ring knife line is 1-5 cm2, the gap length of the intermittent ring knife line is 1-3 mm, the distance between adjacent knife lines is 2-5 mm, and the substrate layer is made of polyvinyl chloride or polyethylene and has a thickness of 50-150 μm.

[0012] Preferably, the preparation method of the temperature-sensitive dynamic grating anti-counterfeiting label comprises the following steps: S1 substrate pretreatment: selecting a polyester film as the substrate, drying the substrate in a drying box to remove surface moisture and impurities, and the water content of the substrate surface after drying is ≤0.5%; S2 dynamic grating layer preparation: preparing a dynamic grating layer on the surface of the pretreated substrate by a molding process, the molding pressure is 5-15 MPa, the molding temperature is 100-150℃, and the formed dynamic grating layer is cooled to room temperature at a speed of 5-10℃ / min, and the grating pitch is 50-200 μm; S3 color grating layer preparation: uniformly coating a color grating paint on the surface of the dynamic grating layer at a coating speed of 1-3 m / min, and drying at 60-80℃ for 20-40 min by hot air to form a color grating layer; S4 crystal relief layer and micro-text forming: preparing a crystal relief layer on the surface of the color grating layer by a UV curing process, coating a UV curing resin on the surface of the color grating layer, pressing a mold containing a micro-text pattern on the surface of the resin, the pressing pressure is 2-5 MPa, then irradiating ultraviolet light for curing, the curing dose is 500-1500 mJ / cm2, and the crystal relief layer with the embedded micro-text inside is obtained after demolding; S5 dynamic silver sand layer preparation: uniformly mixing dynamic silver sand with a particle size of 1-10 μm and polyurethane binder at a mass ratio of 1:3-1:5, coating on the surface of the crystal relief layer by a spraying process, the coating thickness is 8-20 μm, and drying at 70-90℃ for 15-30 min to form a dynamic silver sand layer; S6 photo-variable ink layer preparation: mixing metal particles and acrylic resin photo-variable ink substrate at a mass ratio of 1:5-1:10, stirring at a speed of 1000-3000 r / min for 10-30 min, printing on the surface of the dynamic silver sand layer by a 200-400 mesh silk screen printing process, the printing thickness is 5-15 μm, and drying at 80-100℃ for 10-20 min to form a photo-variable ink layer; S7 preparing temperature-variable ink layer: proportionally weighing fluoran-based leuco dye, bisphenol A-based developer, ethanol-acetic ether mixed solvent and acrylic resin, first adding leuco dye and developer into mixed solvent, stirring and dissolving at 50-60 DEG C for 15-30 min, stirring speed is 500-1000 r / min, then adding acrylic resin, continuing to stir for 20-40 min until mixed uniformly, obtaining temperature-variable ink; adopting doctor blade coating process to coat temperature-variable ink on the surface of photo-variable ink layer, coating speed is 0.5-2 m / min, ventilating and drying at 50-60 DEG C for 15-25 min, forming temperature-variable ink layer; S8 cat-eye lens layer compounding: selecting cat-eye lens film, adopting hot-pressing compounding process to compound cat-eye lens film on the surface of temperature-variable ink layer, compounding temperature is 90-120 DEG C, compounding pressure is 3-8 MPa, compounding time is 5-10 s, cooling to room temperature after compounding; S9 gold stamping treatment: adopting gold stamping process to perform gold stamping treatment on the surface of cat-eye lens layer, gold stamping foil material is aluminum foil or copper foil, gold stamping temperature is 120-180 DEG C, gold stamping pressure is 3-8 MPa, gold stamping time is 1-3 s, gold stamping pattern is adapted to the overall structure of label, forming colorful gold stamping layer; S10 die cutting forming: adopting anti-tearing knife die to die cut the multi-layer structure after compounding, sawtooth angle of the knife die is 30-60 DEG, die cutting speed is 10-30 m / min, die cutting formed knife cutting line is continuous sawtooth knife cutting line, there is no burr on the edge of label after die cutting, obtaining temperature-sensitive dynamic grating anti-fake label.

[0013] Preferably, in step S7, the viscosity of temperature-variable ink is 100-500 mPa·s, after coating, infrared drying mode is adopted for auxiliary drying, infrared drying temperature is 55-65 DEG C, drying time is 5-10 min.

[0014] Preferably, in step S4, the UV curing resin is epoxy acrylate resin or polyurethane acrylate resin, the micro-text pattern on the mold is made by laser engraving, line width precision is ±1 μm, height precision is ±0.5 μm.

[0015] Preferably, in step S10, the arrangement mode of continuous sawtooth knife cutting line is closed ring or intermittent ring, after die cutting, UV curing edge sealing treatment is performed on the edge of label, edge sealing thickness is 2-5 μm, the edge sealing material is UV curing acrylate resin.

[0016] (Three) beneficial technical effects Compared with the prior art, the beneficial effects of the present application are: 1. The label integrates multiple anti-counterfeiting elements such as dynamic grating, color grating, crystal embossing, microtext, optically variable ink, thermochromic ink, and cat's eye lens. These elements work together to form a multi-level anti-counterfeiting system. Individual anti-counterfeiting elements are difficult to counterfeit, and their synergistic effect further raises the anti-counterfeiting threshold, effectively avoiding the shortcomings of single anti-counterfeiting technologies being easily cracked.

[0017] 2. By clarifying the specific formula and proportion of thermochromic ink, the thermochromic ink is made colorless and transparent at room temperature, making it difficult to identify. It achieves irreversible and stable color development within a specific temperature range, with clear color development and accurate response. This solves the problems of unstable color change and reversible failure of existing thermochromic anti-counterfeiting labels, and improves the reliability of temperature-sensitive anti-counterfeiting.

[0018] 3. The dynamic grating layer and the color grating layer work together to create rich dynamic display effects. Combined with the three-dimensional dynamic visual effect of the cat's eye lens, the label has a very strong visual recognition. Ordinary consumers can quickly distinguish between genuine and counterfeit products through intuitive observation, reducing the difficulty of authenticity identification.

[0019] 4. The tear-resistant structure design at the edge of the substrate layer makes the label easily damaged when peeled or torn, preventing it from being reused completely. This effectively prevents criminals from counterfeiting by replacing labels and further ensures the authenticity of the product. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for preparing a temperature-sensitive dynamic grating anti-counterfeiting label disclosed in this invention; Figure 2 This is a line graph comparing the color difference of light change at different viewing angles between the embodiment and the comparative example; Figure 3 This is a physical image of a temperature-sensitive dynamic grating anti-counterfeiting label proposed in this invention; Figure 4 This is a radar comparison chart created by standardizing the performance data of the examples and comparative examples. Detailed Implementation

[0021] according to Figures 1 to 4 The specific embodiments of the present invention are as follows: The following detailed description of the temperature-sensitive dynamic grating anti-counterfeiting label and its preparation method of the present invention is provided in conjunction with specific embodiments.

[0022] Example 1

[0023] 1. Substrate pretreatment Polyvinyl chloride (PVC) was selected as the substrate, with a thickness of 100 μm. The substrate was cut into regular 10 cm × 10 cm sheets and placed in an 80°C constant-temperature drying oven for 2 hours. During the drying process, the substrate was manually turned every 30 minutes to ensure thorough removal of moisture, dust, oil, and other impurities from both the top and bottom surfaces. After drying, the surface moisture content of the substrate was measured using a Karl Fischer moisture meter, and the result was 0.3%.

[0024] 2. Fabrication of dynamic grating layer Polyethylene terephthalate (PET) was selected as the material for the dynamic grating layer, and high-precision flatbed molding machine was used for compression molding. The molding pressure was set to 10 MPa, the molding temperature to 120℃, and the molding holding time to 30 s, allowing the PET material to flow fully within the mold cavity containing the grating pattern and replicate the pattern. After molding, the material was cooled to room temperature at a rate of 8℃ / min using the molding machine's cooling system. After demolding, the dynamic grating layer was obtained. Microscopic observation showed that the grating pitch of the dynamic grating layer was 120 μm, the tilt angle of the grating stripes on the dynamic grating layer was 20°, the stripes were regular and without deformation, and the surface flatness error was ≤2 μm.

[0025] 3. Fabrication of the color grating layer A red-based special colored grating coating was selected and uniformly applied to the surface of the dynamic grating layer using a doctor blade coater. The coating speed was set to 2 m / min, and the coating thickness was controlled to 15 μm by adjusting the doctor blade gap. After coating, the sample was placed in a hot air circulating drying oven at 70℃ for 30 minutes, maintaining an air velocity of 1.5 m / s throughout the drying process to ensure uniform drying of the coating. After drying, the colored grating layer exhibited uniform color and a tight bond with the dynamic grating layer. Adhesion was tested using a cross-cut adhesion test; no coating peeled off after crossing the grid, indicating an adhesion level of 1.

[0026] 4. Crystal relief layer and microtext molding Epoxy acrylate resin was selected as the UV-curing resin. An air spraying process was used to uniformly coat the resin onto the surface of the colored grating layer, achieving a coating thickness of 20 μm. A laser-engraved mold was used, with the surface bearing a microtext pattern of the letters "ABC123". The microtext lines were 20 μm wide and 10 μm high, with an 80 μm spacing between adjacent microtext lines. The laser engraving accuracy was ±1 μm for the line width and ±0.5 μm for the height. The mold was aligned with the coated resin surface, and a hydraulic press was used to apply a pressure of 3 MPa. After maintaining this pressure for 5 seconds, the UV curing equipment was activated at a wavelength of 365 nm and a curing dose of 1000 mJ / cm² for 30 seconds to complete the curing. After demolding, metallographic microscopy revealed a smooth surface of the crystal relief layer, with clearly legible microtext, free from defects or deformation, and evenly spaced along the texture of the crystal relief layer.

[0027] 5. Preparation of dynamic silver layer Dynamic abrasive silver powder with a particle size of 5μm was selected and mixed with polyurethane binder at a mass ratio of 1:4. The mixture was then placed in a high-speed disperser and stirred at 2000 rpm for 15 minutes to ensure uniform dispersion of the abrasive silver powder in the binder without agglomeration. The mixture was then applied to the surface of the crystal relief layer using an air spraying process. The spraying pressure was adjusted to 0.3 MPa, and the coating thickness was controlled to 12μm. After coating, the sample was placed in an 80℃ drying oven for 20 minutes. After drying, the dynamic abrasive silver layer exhibited a uniform abrasive silver luster, with no missed areas or lumps.

[0028] 6. Preparation of Optically Variable Ink Layer Aluminum powder was selected as the metal particle, with a particle size of 30 nm and a metal particle mass ratio of 15%. The aluminum powder and acrylic resin photochromic ink substrate were mixed at a mass ratio of 1:8 and placed in a planetary mixer. The mixture was stirred at 2000 rpm for 20 minutes, with the mixer stopped every 5 minutes to ensure uniform ink distribution and no sedimentation. The photochromic ink was printed onto the surface of the dynamic silver layer using a 300-mesh screen printing machine. The screen tension was adjusted to 25 N, controlling the printing thickness to 10 μm. After printing, the ink was dried in a 90℃ drying oven for 15 minutes. After drying, a colorimeter was used to measure the colors of the photochromic ink layer at 30°, 60°, 90°, and 120° viewing angles. The colors were light gold, golden red, deep red, and dark red, respectively, with color differences ΔE of 3.5, 4.2, 3.8, and 4.0, all ≥3.0.

[0029] 7. Preparation of thermochromic ink layer The raw materials were weighed according to the following mass proportions: 10% by mass for fluorane leuco dye (3,3-bis(4-dimethylaminophenyl)-6-dimethylaminofluorane); 15% by mass for bisphenol A developer (4,4'-dihydroxydiphenylpropane); 50% by mass for a 2:1 volume ratio of ethanol-ethyl acetate mixed solvent; and 25% by mass for acrylic resin film-forming agent. The leuco dye and developer were added to the mixed solvent and placed in a constant-temperature water bath mixer at 55°C and 800 rpm for 25 minutes until the solution was clear and free of particles. Then, the acrylic resin was added, and stirring was continued at the same speed for 30 minutes to obtain a uniform thermochromic ink. The ink viscosity was measured to be 300 mPa·s using a rotational viscometer. The thermochromic ink was then coated onto the surface of the photochromic ink layer using a doctor blade coater at a speed of 1 m / min and a coating thickness of 12 μm. After coating, the ink was first dried in a ventilated drying oven at 55℃ for 20 minutes, and then dried with the assistance of an infrared dryer at 60℃ for 8 minutes. This thermochromic ink layer is an irreversible thermochromic type, colorless and transparent at room temperature, and cannot be identified by the naked eye. Using a constant temperature water bath for gradual heating test, it began to turn red when the temperature reached 70℃. When the temperature was further increased to 75℃, the red color was completely stable. After cooling to room temperature, the color remained unchanged, and the color development was clear and uniform. Repeated heating three times showed no fading or color change.

[0030] 8. Cat's eye lens layer composite A 1.2mm focal length cat's eye lens film was selected and laminated onto the surface of the thermochromic ink layer using a hot press laminator. The lamination temperature was set at 100℃, the lamination pressure at 5MPa, and the lamination time at 8s. During the lamination process, the temperature at the lamination interface was monitored in real time using a temperature sensor to ensure uniform temperature. After lamination, the film was allowed to cool naturally to room temperature. The cat's eye lens film and the thermochromic ink layer were tightly laminated without any bubbles or peeling. By visual observation, the label exhibited a distinct three-dimensional dynamic visual effect at different angles, demonstrating a significant synergistic effect with the color grating layer and the dynamic grating layer.

[0031] 9. Hot stamping Aluminum foil was selected for hot stamping, and a flatbed hot stamping machine was used to apply the hot stamping to the surface of the cat's eye lens layer. The hot stamping temperature was set to 150℃, the hot stamping pressure to 5MPa, and the hot stamping time to 2 seconds. The hot stamping pattern was designed as a circular design, which matched the overall structure of the label. After hot stamping, an adhesive tape test was conducted using 3M 600 tape. The tape was applied at a pressure of 0.5MPa and held for 10 seconds before being quickly peeled off. There was no peeling or flaking of the hot stamping layer, and the surface exhibited a colorful visual effect.

[0032] 10. Die-cutting The multi-layered composite structure was die-cut using a tear-resistant die. The die's serration angle was set to 45°, and the die-cutting speed was 20 m / min. The tear-resistant structure consisted of a continuous, closed-loop serrated cut line integrally formed on the substrate layer. The cut line depth was 2 / 3 of the substrate thickness, and the area enclosed by the closed-loop cut line was 3 cm². After die-cutting, under magnification, the label edges were free of burrs and flash, with a dimensional accuracy error ≤ ±0.1 mm. Subsequently, the label edges were UV-cured and sealed using UV-curable acrylic resin. The sealing material was 3 μm thick, and curing was completed in 10 seconds using a UV LED curing machine with a wavelength of 395 nm and a power of 80 W. After sealing, the label edges were smooth, exhibiting excellent waterproof and scratch-resistant properties.

[0033] Example 2

[0034] 1. Substrate pretreatment Polyethylene was selected as the substrate, with a thickness of 60 μm. The substrate was cut into 8 cm × 8 cm sheets and placed in a 75°C electric thermostatic drying oven for 1.5 hours, turning it over every 20 minutes during drying. After drying, the surface moisture content of the substrate was measured to be 0.2%.

[0035] 2. Fabrication of dynamic grating layer Polycarbonate was selected as the material for the dynamic grating layer, and it was molded using a high-precision flatbed molding machine. The molding pressure was set to 6 MPa, the molding temperature to 110℃, and the molding holding time to 25 s. After molding, it was cooled to room temperature at a rate of 5℃ / min to obtain a dynamic grating layer with a grating pitch of 90 μm and a grating stripe tilt angle of 10°. The stripes were regular, and the surface flatness error was ≤3 μm.

[0036] 3. Fabrication of the color grating layer A special blue-toned grating coating was selected and applied using a doctor blade coater at a speed of 1.5 m / min to a thickness of 12 μm. The coating was then dried in a 65°C hot air circulating drying oven for 25 min. After drying, the coating had a uniform color and an adhesion rating of 1 in the cross-cut adhesion test.

[0037] 4. Crystal relief layer and microtext molding Polyurethane acrylate resin was selected as the UV-curing resin and applied using an air spraying process to a thickness of 18μm. A laser-engraved mold was used, with the microtext "XYZ789" on its surface, featuring a line width of 15μm, a height of 8μm, and an adjacent spacing of 60μm. The engraving accuracy was ±1μm for line width and ±0.5μm for height. A hydraulic press was applied with a pressure of 2.5MPa, held for 4 seconds, and then irradiated with a curing dose of 800mJ / cm² for 25 seconds for curing. After demolding, the microtext was clear and well-matched with the embossed texture.

[0038] 5. Preparation of dynamic silver layer Dynamic silver powder with a particle size of 3μm was selected and mixed with polyurethane binder at a mass ratio of 1:3. The mixture was stirred at a speed of 1500r / min for 12min and then applied using an air spraying process to a thickness of 10μm. The mixture was then placed in a drying oven at 75℃ for 18min to dry. After drying, the surface had a uniform gloss and no missed areas.

[0039] 6. Preparation of Optically Variable Ink Layer Copper powder with a particle size of 20 nm and a mass ratio of 10% was selected as the metal particles and mixed with acrylic resin photochromic ink substrate at a mass ratio of 1:6. The mixture was stirred at 1500 rpm for 15 min, screen printed with a 250-mesh screen to a thickness of 8 μm, and dried at 85℃ for 12 min. Colorimeter measurements showed that the color difference values ​​ΔE at viewing angles of 30°, 60°, 90°, and 120° were 3.2, 3.8, 3.4, and 3.6, respectively, all ≥3.0.

[0040] 7. Preparation of thermochromic ink layer The raw materials were weighed according to the following mass ratios: 8% 3-diethylamino-7-chlorofluorane, 12% 4,4'-dihydroxydiphenyl sulfone, 55% ethanol-ethyl acetate (1:1 ratio), and 25% acrylic resin. The leuco dye and color developer were added to the mixed solvent and placed in a constant-temperature water bath mixer at 52°C and 600 rpm for 20 minutes until the solution was clear and free of particles. Then, the acrylic resin was added, and stirring continued at the same speed for 25 minutes to obtain a uniform thermochromic ink. The viscosity of the ink was measured to be 200 mPa·s using a rotational viscometer. The thermochromic ink was then coated onto the surface of the photochromic ink layer using a doctor blade coater at a speed of 0.8 m / min and a coating thickness of 10 μm. After coating, the ink was first dried in a ventilated drying oven at 52°C for 18 minutes, followed by assisted drying using an infrared dryer at 58°C for 6 minutes. The thermochromic ink layer is an irreversible thermochromic type. It is colorless and transparent at room temperature and cannot be detected by the naked eye. After gradient heating test, it begins to turn red when the temperature reaches 70℃. The red color is completely stable when the temperature is raised to 75℃. After cooling to room temperature, the red color remains unchanged and is irreversible. Repeated heating and cooling tests show that the color development is always stable.

[0041] 8. Cat's eye lens layer composite A cat's-eye lens film with a focal length of 0.8mm was selected and laminated onto the surface of the thermochromic ink layer using a hot-press laminator. The lamination temperature was set to 95℃, the lamination pressure to 4MPa, and the lamination time to 6s. During the lamination process, the temperature at the lamination interface was monitored in real time using a temperature sensor to ensure uniform temperature. After lamination, the film was allowed to cool naturally to room temperature. The cat's-eye lens film and the thermochromic ink layer were tightly laminated without any bubbles or peeling. By visual observation, the label exhibited a distinct three-dimensional dynamic visual effect at different angles, demonstrating a significant synergistic effect with the color grating layer and the dynamic grating layer.

[0042] 9. Hot stamping Copper foil hot stamping foil was selected and applied to the surface of the cat's eye lens layer using a flatbed hot stamping machine. The hot stamping temperature was set to 130℃, the hot stamping pressure to 4MPa, and the hot stamping time to 1.5s. The hot stamping pattern was designed as a striped design, compatible with the overall structure of the label. After hot stamping, an adhesive tape test was conducted using 3M 600 tape. With an adhesion pressure of 0.5MPa, the tape was held for 10 seconds and then quickly peeled off. No gold peeling or flaking was observed, and the surface exhibited a vibrant, multicolored visual effect.

[0043] 10. Die-cutting The multi-layered composite structure was die-cut using a tear-resistant die. The die's serration angle was set to 35°, and the die-cutting speed was 15 m / min. The tear-resistant structure consisted of discontinuous, continuous, annular serrated cut lines integrally formed on the substrate layer. The depth of the cut lines was half the substrate thickness, the notch length of the discontinuous annular cut lines was 2 mm, and the spacing between adjacent cut lines was 3 mm. After die-cutting, under magnification, the label edges were free of burrs and flash, with a dimensional accuracy error ≤ ±0.1 mm. Subsequently, the label edges were UV-cured and sealed using UV-curable acrylic resin. The sealing material was 2.5 μm thick, and curing was completed in 8 seconds using a UV LED curing machine with a wavelength of 395 nm and a power of 80 W. After sealing, the label edges were smooth, exhibiting excellent waterproof and scratch-resistant properties.

[0044] Example 3

[0045] 1. Substrate pretreatment Polyvinyl chloride (PVC) was selected as the substrate, with a thickness of 140 μm. The substrate was cut into regular 12cm × 12cm sheets and placed in an 85℃ electric thermostatic drying oven for 2.5 hours. During the drying process, the substrate was manually turned every 30 minutes to ensure thorough removal of moisture and adhering dust, oil, and other impurities from both the top and bottom surfaces. After drying, the surface moisture content of the substrate was measured using a Karl Fischer moisture meter, and the result was 0.4%.

[0046] 2. Fabrication of dynamic grating layer Polyethylene terephthalate (PET) was selected as the material for the dynamic grating layer, and high-precision flatbed molding machine was used for compression molding. The molding pressure was set to 14 MPa, the molding temperature to 140℃, and the molding holding time to 35 s, allowing the PET material to flow fully within the mold cavity containing the grating pattern and replicate the pattern. After molding, the material was cooled to room temperature at a rate of 10℃ / min using the molding machine's cooling system. After demolding, the dynamic grating layer was obtained. Microscopic observation showed that the grating pitch of the dynamic grating layer was 140 μm, the tilt angle of the grating stripes on the dynamic grating layer was 40°, the stripes were regular and without deformation, and the surface flatness error was ≤2 μm.

[0047] 3. Fabrication of the color grating layer A green-based special colored grating coating was selected and uniformly applied to the surface of the dynamic grating layer using a doctor blade coater. The coating speed was set to 2.5 m / min, and the coating thickness was controlled to 18 μm by adjusting the doctor blade gap. After coating, the sample was placed in a hot air circulating drying oven at a temperature of 78℃ for 35 minutes. During the drying process, the air velocity inside the oven was maintained at 1.5 m / s to ensure uniform drying of the coating. After drying, the colored grating layer showed uniform color and a tight bond with the dynamic grating layer. Adhesion was tested using a cross-cut adhesion test; no coating peeled off after crossing the grid, indicating an adhesion level of 1.

[0048] 4. Crystal relief layer and microtext molding Epoxy acrylate resin was selected as the UV-curing resin. An air spraying process was used to uniformly coat the resin onto the surface of the colored grating layer, achieving a coating thickness of 22 μm. A laser-engraved mold was used, with the microtext pattern "DEF456" on its surface. The microtext had a line width of 28 μm, a height of 14 μm, and a spacing of 90 μm between adjacent microtexts. The laser engraving accuracy was ±1 μm for line width and ±0.5 μm for height. The mold was aligned with the coated resin surface, and a pressure of 4.5 MPa was applied using a hydraulic press. After maintaining this pressure for 5 seconds, the UV curing equipment was activated at a wavelength of 365 nm and a curing dose of 1400 mJ / cm² for 35 seconds to complete the curing. After demolding, metallographic microscopy revealed a smooth surface of the crystal relief layer, with clearly legible microtext, free from defects or deformation, and evenly spaced along the texture of the crystal relief layer.

[0049] 5. Preparation of dynamic silver layer Dynamic abrasive silver powder with a particle size of 9μm was selected and mixed with polyurethane binder at a mass ratio of 1:5. The mixture was then placed in a high-speed disperser and stirred at 2500 rpm for 18 minutes to ensure uniform dispersion of the abrasive silver powder in the binder without agglomeration. The mixed slurry was then applied to the surface of the crystal relief layer using an air spraying process. The spraying pressure was adjusted to 0.3 MPa, and the coating thickness was controlled to 18μm. After coating, the sample was placed in an 88℃ drying oven for 28 minutes. After drying, the surface of the dynamic abrasive silver layer exhibited a uniform abrasive silver luster, with no missed areas or lumps.

[0050] 6. Preparation of Optically Variable Ink Layer Aluminum powder was selected as the metal particle, with a particle size of 45 nm and a metal particle mass ratio of 22%. The aluminum powder and acrylic resin photochromic ink substrate were mixed at a mass ratio of 1:9 and placed in a planetary mixer. The mixture was stirred at 2800 rpm for 28 minutes, with the mixer stopped every 5 minutes to ensure uniform ink distribution and no sedimentation. The photochromic ink was printed onto the dynamic silver layer using a 380-mesh screen printing machine. The screen tension was adjusted to 25 N, controlling the printing thickness to 14 μm. After printing, the ink was dried in a 98°C drying oven for 18 minutes. After drying, the color difference ΔE of the photochromic ink layer was measured using a colorimeter, and all values ​​(30°, 60°, 90°, and 120°) were ≥3.9.

[0051] 7. Preparation of thermochromic ink layer Raw materials were weighed according to the following mass proportions: 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminofluorane was selected as the fluorane leuco dye, accounting for 14% by mass; 4,4'-dihydroxydiphenylpropane was selected as the bisphenol A developer, accounting for 19% by mass; the volume ratio of ethanol-ethyl acetate mixed solvent was 3:1, accounting for 48% by mass; and the acrylic resin film-forming agent accounted for 19% by mass. The leuco dye and developer were added to the mixed solvent and placed in a constant temperature water bath stirrer. The temperature was set to 58℃, and the stirring speed was 950 r / min. Stirring was continued for 28 min until the solution was clear and free of particles. Then, the acrylic resin was added, and stirring was continued at the same speed for 38 min to obtain a uniform thermochromic ink. The ink viscosity was measured to be 450 mPa·s using a rotational viscometer. The thermochromic ink was then coated onto the surface of the photochromic ink layer using a doctor blade coater, with a coating speed of 1.8 m / min and a coating thickness of 14 μm. After coating, the ink was first dried in a ventilated drying oven at 58℃ for 24 minutes, and then dried with the assistance of an infrared dryer at 63℃ for 9 minutes. This thermochromic ink layer is an irreversible thermochromic type, colorless and transparent at room temperature, and cannot be identified by the naked eye. Using a constant temperature water bath for gradual heating test, it began to turn red when the temperature reached 70℃. When the temperature was further increased to 75℃, the red color was completely stable. After cooling to room temperature, the color remained unchanged, and the color development was clear and uniform. Repeated heating three times showed no fading or color change.

[0052] 8. Cat's eye lens layer composite A cat's-eye lens film with a focal length of 1.8mm was selected and laminated onto the surface of the thermochromic ink layer using a hot-press laminator. The lamination temperature was set at 115℃, the lamination pressure at 7MPa, and the lamination time at 9s. During the lamination process, the temperature at the lamination interface was monitored in real time using a temperature sensor to ensure uniform temperature. After lamination, the film was allowed to cool naturally to room temperature. The cat's-eye lens film and the thermochromic ink layer were tightly laminated without any bubbles or peeling. By visual observation, the label exhibited a distinct three-dimensional dynamic visual effect at different angles, demonstrating a significant synergistic effect with the color grating layer and the dynamic grating layer.

[0053] 9. Hot stamping Aluminum foil was selected for hot stamping, and a flatbed hot stamping machine was used to apply the hot stamping to the surface of the cat's eye lens layer. The hot stamping temperature was set to 170℃, the hot stamping pressure to 7MPa, and the hot stamping time to 2.8s. The hot stamping pattern was designed as a circular design, which matched the overall structure of the label. After hot stamping, an adhesive tape test was conducted using 3M 600 tape. The tape was applied at a pressure of 0.5MPa and held for 10 seconds before being quickly peeled off. There was no peeling or flaking of the hot stamping layer, and the surface exhibited a colorful visual effect.

[0054] 10. Die-cutting The multi-layered composite structure was die-cut using a tear-resistant die with a serration angle of 55° and a cutting speed of 28 m / min. The tear-resistant structure consists of a continuous, closed-loop serrated cut line integrally formed on the substrate layer. The cut line depth is 3 / 4 of the substrate thickness, and the area enclosed by the closed-loop cut line is 4.5 cm². After die-cutting, under magnification, the label edges were free of burrs and flash, with a dimensional accuracy error ≤ ±0.1 mm. Subsequently, the label edges were UV-cured and sealed using UV-curable acrylic resin with a thickness of 4.5 μm. A UV LED curing machine with a wavelength of 395 nm and a power of 80 W was used, curing for 12 seconds. After sealing, the label edges were smooth, exhibiting excellent waterproof and scratch-resistant properties.

[0055] Comparative Example 1. Substrate pretreatment Polyvinyl chloride (PVC) was selected as the substrate, with a thickness of 100 μm. The substrate was cut into regular 10 cm × 10 cm sheets and placed in an 80°C constant-temperature drying oven for 2 hours. During the drying process, the substrate was manually turned every 30 minutes to ensure thorough removal of moisture, dust, oil, and other impurities from both the top and bottom surfaces. After drying, the surface moisture content of the substrate was measured using a Karl Fischer moisture meter, and the result was 0.3%.

[0056] 2. Fabrication of dynamic grating layer Polyethylene terephthalate (PET) was selected as the material for the dynamic grating layer, and high-precision flatbed molding machine was used for compression molding. The molding pressure was set to 10 MPa, the molding temperature to 120℃, and the molding holding time to 30 s, allowing the PET material to flow fully within the mold cavity containing the grating pattern and replicate the pattern. After molding, the material was cooled to room temperature at a rate of 8℃ / min using the molding machine's cooling system. After demolding, the dynamic grating layer was obtained. Microscopic observation showed that the grating pitch of the dynamic grating layer was 120 μm, the tilt angle of the grating stripes on the dynamic grating layer was 20°, the stripes were regular and without deformation, and the surface flatness error was ≤2 μm.

[0057] 3. Fabrication of the color grating layer A red-based special colored grating coating was selected and uniformly applied to the surface of the dynamic grating layer using a doctor blade coater. The coating speed was set to 2 m / min, and the coating thickness was controlled to 15 μm by adjusting the doctor blade gap. After coating, the sample was placed in a hot air circulating drying oven at 70℃ for 30 minutes, maintaining an air velocity of 1.5 m / s throughout the drying process to ensure uniform drying of the coating. After drying, the colored grating layer exhibited uniform color and a tight bond with the dynamic grating layer. Adhesion was tested using a cross-cut adhesion test; no coating peeled off after crossing the grid, indicating an adhesion level of 1.

[0058] 4. Crystal relief layer forming Epoxy acrylate resin was selected as the UV curing resin. An air spraying process was used to uniformly coat the resin onto the surface of the colored grating layer, achieving a coating thickness of 20 μm. A hydraulic press was used to apply a pressure of 3 MPa, which was maintained for 5 seconds. Then, the UV curing equipment was activated at a wavelength of 365 nm and a curing dose of 1000 mJ / cm² for 30 seconds to complete the curing. After demolding, a crystal relief layer without microtext was obtained, with a smooth surface and no obvious defects.

[0059] 5. Preparation of dynamic silver layer Dynamic abrasive silver powder with a particle size of 5μm was selected and mixed with polyurethane binder at a mass ratio of 1:4. The mixture was then placed in a high-speed disperser and stirred at 2000 rpm for 15 minutes to ensure uniform dispersion of the abrasive silver powder in the binder without agglomeration. The mixture was then applied to the surface of the crystal relief layer using an air spraying process. The spraying pressure was adjusted to 0.3 MPa, and the coating thickness was controlled to 12μm. After coating, the sample was placed in an 80℃ drying oven for 20 minutes. After drying, the dynamic abrasive silver layer exhibited a uniform abrasive silver luster, with no missed areas or lumps.

[0060] 6. Preparation of Optically Variable Ink Layer Aluminum powder was selected as the metal particle, with a particle size of 30 nm and a mass ratio of 5%. The aluminum powder and acrylic resin photochromic ink substrate were mixed at a mass ratio of 1:8 and placed in a planetary mixer. The mixture was stirred at 2000 rpm for 20 minutes, with the mixer stopped every 5 minutes to ensure uniform ink distribution and no sedimentation. The photochromic ink was printed onto the surface of the dynamic silver layer using a 300-mesh screen printing machine. The screen tension was adjusted to 25 N, controlling the printing thickness to 10 μm. After printing, the ink was dried in a 90°C oven for 15 minutes. After drying, the color difference was measured using a colorimeter. The color difference values ​​ΔE of the photochromic ink layer at viewing angles of 30°, 60°, 90°, and 120° were 2.2, 2.5, 2.3, and 2.4, respectively, all <3.0.

[0061] 7. Preparation of thermochromic ink layer The raw materials were weighed according to the following mass proportions: 10% by mass for fluorane leuco dye (3,3-bis(4-dimethylaminophenyl)-6-dimethylaminofluorane); 15% by mass for bisphenol A developer (4,4'-dihydroxydiphenylpropane); 50% by mass for a 2:1 volume ratio of ethanol-ethyl acetate mixed solvent; and 25% by mass for acrylic resin film-forming agent. The leuco dye and developer were added to the mixed solvent and placed in a constant-temperature water bath mixer at 55°C and 800 rpm for 25 minutes until the solution was clear and free of particles. Then, the acrylic resin was added, and stirring was continued at the same speed for 30 minutes to obtain a uniform thermochromic ink. The ink viscosity was measured to be 300 mPa·s using a rotational viscometer. The thermochromic ink was then coated onto the surface of the photochromic ink layer using a doctor blade coater at a speed of 1 m / min and a coating thickness of 12 μm. After coating, the ink was first dried in a ventilated drying oven at 55℃ for 20 minutes, followed by assisted drying using an infrared dryer at 60℃ for 8 minutes. This thermochromic ink layer is a reversible thermochromic type, colorless and transparent at room temperature, and indistinguishable to the naked eye. Using a constant-temperature water bath with gradual temperature increases, it began to turn red at 70℃. Upon further heating to 75℃, the red color became completely stable, but upon cooling to room temperature, the color gradually faded, returning to colorless. After repeated heating and cooling cycles, the color stability gradually decreased.

[0062] 8. Cat's eye lens layer composite A 1.2mm focal length cat's eye lens film was selected and laminated onto the surface of the thermochromic ink layer using a hot press laminator. The lamination temperature was set at 100℃, the lamination pressure at 5MPa, and the lamination time at 8s. During the lamination process, the temperature at the lamination interface was monitored in real time using a temperature sensor to ensure uniform temperature. After lamination, the film was allowed to cool naturally to room temperature. The cat's eye lens film and the thermochromic ink layer were tightly laminated without any bubbles or peeling. By visual observation, the label exhibited a distinct three-dimensional dynamic visual effect at different angles, demonstrating a significant synergistic effect with the color grating layer and the dynamic grating layer.

[0063] 9. Hot stamping Aluminum foil was selected for hot stamping, and a flatbed hot stamping machine was used to apply the hot stamping to the surface of the cat's eye lens layer. The hot stamping temperature was set to 150℃, the hot stamping pressure to 5MPa, and the hot stamping time to 2 seconds. The hot stamping pattern was designed as a circular design, which matched the overall structure of the label. After hot stamping, an adhesive tape test was conducted using 3M 600 tape. The tape was applied at a pressure of 0.5MPa and held for 10 seconds before being quickly peeled off. There was no peeling or flaking of the hot stamping layer, and the surface exhibited a colorful visual effect.

[0064] 10. Die-cutting The multi-layered composite structure was die-cut using a standard die at a speed of 20 m / min. After die-cutting, magnification revealed no burrs or flash on the label edges, and the dimensional accuracy error was ≤ ±0.1 mm. No edge sealing was performed. The label peeled off completely without tear resistance.

[0065] The anti-counterfeiting response characteristics of the examples and comparative examples are compared in the table below: Table 1

[0066] The physical properties and reliability of the embodiments and comparative examples are compared in the table below: Table 2

[0067] The two performance comparison tables clearly show that the temperature-sensitive dynamic grating anti-counterfeiting labels of Examples 1-3 exhibit excellent performance in anti-counterfeiting response characteristics, physical properties, and reliability: the temperature change trigger temperature accuracy reaches 70℃±1℃, the optical color difference ΔE is ≥3.2, the microtext recognition is 100%, and the tear resistance is <5N, the coating adhesion is Grade 1, and the abrasion resistance and water resistance are stable, fully meeting the technical requirements of the claims. In contrast, the comparative examples lack microtext anti-counterfeiting elements, have large temperature change response fluctuations, optical color change ΔE <3.0, and lack tear-resistant structures and effective edge sealing, resulting in significantly inferior anti-counterfeiting effects, physical stability, and reliability compared to the examples. This fully demonstrates the high security and high reliability technical advantages achieved by the present invention through the collaborative design of multiple anti-counterfeiting elements and precise process parameter control.

[0068] Reference Figure 4 The radar comparison charts of Examples 1-3 and the comparative examples are based on performance data with unified dimensions. The comparison focuses on key performance indicators such as tear resistance, temperature storage stability, coating adhesion level, edge sealing waterproofness, abrasion resistance, and non-trigger temperature zone stability. The comparisons visually demonstrate that the temperature-sensitive dynamic grating anti-counterfeiting label of the present invention has significant technical advantages over the comparative examples in terms of various performance and reliability.

[0069] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A temperature-sensitive dynamic grating anti-counterfeiting label, characterized in that, The composite structure, from top to bottom, consists of a hot stamping layer, a cat's-eye lens layer, a thermochromic ink layer, an optically variable ink layer, a dynamic sandblasted silver layer, a crystal embossed layer, a colored grating layer, a dynamic grating layer, and a substrate layer. The substrate layer has a tear-resistant structure at its edges. The dynamic grating layer and the colored grating layer form a synergistic dynamic display structure with a grating pitch of 50μm to 200μm. The optically variable ink layer contains metal particles and exhibits a multi-color changing effect within a viewing angle range of 0° to 180°. The thermochromic ink layer is an irreversible thermochromic type, composed of fluorescein-based leuco dyes, bisphenol A-based color developers, an ethanol-ethyl acetate mixed solvent, and an acrylic resin film-forming agent. The cat's-eye lens layer, the colored grating layer, and the dynamic grating layer work together to create a three-dimensional dynamic visual effect, with a lens focal length of 0.5mm to 2.0mm. The crystal embossed layer contains embedded microtext. The hot stamping layer presents a colorful visual effect.

2. The temperature-sensitive dynamic grating anti-counterfeiting label according to claim 1, characterized in that, The microtext is arranged at intervals along the texture direction of the crystal relief layer, and the microtext has a line width of 10μm to 30μm, a height of 5μm to 15μm, and a spacing of 50μm to 100μm between adjacent microtexts.

3. The temperature-sensitive dynamic grating anti-counterfeiting label according to claim 1, characterized in that, The dynamic grating layer has a grating pitch of 80μm to 150μm and is made of polyethylene terephthalate or polycarbonate. The tilt angle of the grating stripes on the dynamic grating layer is 0° to 45°.

4. The temperature-sensitive dynamic grating anti-counterfeiting label according to claim 1, characterized in that, In the thermochromic ink layer, the leuco dye is selected from 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminofluorane or 3-diethylamino-7-chlorofluorane, the bisphenol A color developer is selected from 4,4'-dihydroxydiphenylpropane or 4,4'-dihydroxydiphenyl sulfone, and the volume ratio of ethanol to ethyl acetate in the mixed solvent is 1:1 to 3:1; wherein the leuco dye accounts for 5% to 15% of the mass, the color developer accounts for 10% to 20% of the mass, the mixed solvent accounts for 40% to 60% of the mass, and the acrylic resin film-forming agent accounts for 15% to 30% of the mass.

5. The temperature-sensitive dynamic grating anti-counterfeiting label according to claim 1, characterized in that, The metal particles in the photochromic ink layer are aluminum powder or copper powder, with a particle size of 10nm to 50nm and a mass ratio of 8% to 25%. They exhibit different color depth changes at viewing angles of 30°, 60°, 90° and 120°, with a color difference ΔE ≥ 3.

0.

6. The temperature-sensitive dynamic grating anti-counterfeiting label according to claim 1, characterized in that, The tear-resistant structure is an integrally formed continuous serrated cutting line on the substrate layer. The depth of the cutting line is 1 / 2 to 3 / 4 of the substrate thickness. The continuous serrated cutting line is a closed loop or an intermittent loop. The area enclosed by the closed loop cutting line is 1 cm² to 5 cm². The notch length of the intermittent loop cutting line is 1 mm to 3 mm. The spacing between adjacent cutting lines is 2 mm to 5 mm. The substrate layer is made of polyvinyl chloride or polyethylene and has a thickness of 50 μm to 150 μm.

7. A method for preparing a temperature-sensitive dynamic grating anti-counterfeiting label as described in claim 1, characterized in that, Includes the following steps: S1 Substrate Pretreatment: Select polyester film as the substrate, place the substrate in a drying oven to dry, remove surface moisture and impurities, and the surface moisture content of the substrate after drying is ≤0.5%; S2 Dynamic Grating Layer Preparation: A dynamic grating layer is prepared on the surface of a pretreated substrate using a molding process. The molding pressure is 5MPa to 15MPa, the molding temperature is 100℃ to 150℃, and after molding, it is cooled to room temperature at a rate of 5℃ / min to 10℃ / min to obtain a dynamic grating layer with a grating pitch of 50μm to 200μm. Preparation of S3 color grating layer: The color grating coating is uniformly coated on the surface of the dynamic grating layer at a coating speed of 1m / min to 3m / min, and then dried with hot air at 60℃ to 80℃ for 20min to 40min to form the color grating layer. S4 Crystal Relief Layer and Microtext Molding: A crystal relief layer is prepared on the surface of a colored grating layer using a UV curing process. First, UV-curable resin is coated on the surface of the colored grating layer. Then, a mold containing microtext patterns is pressed onto the resin surface at a pressure of 2MPa to 5MPa. Subsequently, ultraviolet light is passed through for curing at a curing dose of 500mJ / cm² to 1500mJ / cm². After demolding, a crystal relief layer with microtext embedded inside is obtained. Preparation of S5 dynamic sand silver layer: Dynamic sand silver powder with a particle size of 1μm to 10μm is mixed with polyurethane binder at a mass ratio of 1:3 to 1:

5. The mixture is then applied to the surface of the crystal relief layer using a spraying process. The coating thickness is 8μm to 20μm. The mixture is dried at 70℃ to 90℃ for 15min to 30min to form a dynamic sand silver layer. Preparation of S6 photochromic ink layer: Metal particles and acrylic resin photochromic ink substrate are mixed at a mass ratio of 1:5 to 1:10, the stirring speed is 1000 r / min to 3000 r / min, the stirring time is 10 min to 30 min, and the mixture is printed on the surface of dynamic sand silver layer using a 200 mesh to 400 mesh screen printing process. The printing thickness is 5 μm to 15 μm, and the mixture is dried at 80℃ to 100℃ for 10 min to 20 min to form photochromic ink layer. Preparation of S7 thermochromic ink layer: Weigh out fluorane leuco dye, bisphenol A color developer, ethanol-ethyl acetate mixed solvent and acrylic resin according to the proportion. First, add the leuco dye and color developer to the mixed solvent and stir to dissolve at 50℃~60℃ for 15min~30min at a stirring speed of 500r / min~1000r / min. Then add the acrylic resin and continue stirring for 20min~40min until the mixture is uniform to obtain thermochromic ink. Apply the thermochromic ink to the surface of the photochromic ink layer using a doctor blade coating process at a coating speed of 0.5m / min~2m / min. Air dry at 50℃~60℃ for 15min~25min to form thermochromic ink layer. S8 Cat's Eye Lens Layer Composite: Select cat's eye lens film and use hot-pressing composite process to composite it onto the surface of thermochromic ink layer. The composite temperature is 90℃~120℃, the composite pressure is 3MPa~8MPa, the composite time is 5s~10s, and then cool to room temperature after composite. S9 Hot Stamping: Hot stamping is performed on the surface of the cat's eye lens layer using a hot stamping process. The hot stamping foil material is aluminum foil or copper foil. The hot stamping temperature is 120℃~180℃, the hot stamping pressure is 3MPa~8MPa, and the hot stamping time is 1s~3s. The hot stamping pattern is adapted to the overall structure of the label to form a colorful hot stamping layer. S10 Die-cutting: The multi-layered composite structure is die-cut using a tear-resistant die. The sawtooth angle of the die is 30° to 60°, and the die-cutting speed is 10m / min to 30m / min. The die-cutting line is a continuous sawtooth line. After die-cutting, the label edge is burr-free, resulting in a temperature-sensitive dynamic grating anti-counterfeiting label.

8. The method for preparing the temperature-sensitive dynamic grating anti-counterfeiting label according to claim 7, characterized in that, In step S7, the viscosity of the thermochromic ink is 100 mPa·s to 500 mPa·s. After coating, it is dried by infrared drying, with an infrared drying temperature of 55℃ to 65℃ and a drying time of 5 min to 10 min.

9. The method for preparing the temperature-sensitive dynamic grating anti-counterfeiting label according to claim 7, characterized in that, In step S4, the UV-cured resin is epoxy acrylate resin or polyurethane acrylate resin, and the microtext pattern on the mold is made by laser engraving with a line width accuracy of ±1μm and a height accuracy of ±0.5μm.

10. The method for preparing the temperature-sensitive dynamic grating anti-counterfeiting label according to claim 7, characterized in that, In step S10, the continuous serrated cutting lines are arranged in a closed loop or a discontinuous loop. After die-cutting, the label edges are UV-cured and sealed with an edge thickness of 2μm to 5μm. The sealing material is UV-cured acrylic resin.

Images