Ultraviolet light response anti-counterfeiting element and preparation method thereof

Abstract

The invention provides an ultraviolet light response anti-counterfeiting element and a preparation method thereof, and the ultraviolet light response anti-counterfeiting element comprises a base material which is a transparent material; the optical structure area is filled with a colorless fluorescent material, the optical structure area is arranged on the surface of one side of the base material, and at least one part of the optical structure area is provided with a micro-nano structure area with the surface fluctuating, so that the optical structure area generates an embossment anti-counterfeiting effect and / or a dynamic anti-counterfeiting effect; at least one part of the covering layer is arranged on the side, away from the base material, of the optical structure area; when a light source is adopted to irradiate the ultraviolet light response anti-counterfeiting element, the embossment anti-counterfeiting effect and / or the dynamic anti-counterfeiting effect with the anti-counterfeiting color generated by the optical structure area can be observed on the outer side of the base material and / or the outer side of the covering layer. The problem that in the prior art, an anti-fake element is poor in anti-fake capacity is solved.

Description

Technical Field

[0001] The present invention relates to the field of optical anti-counterfeiting, and in particular to an anti-counterfeiting element responsive to ultraviolet light and a preparation method thereof. Background Art

[0002] In order to prevent counterfeiting by scanning and copying, UV-responsive fluorescent ink technology is widely used in various high-security or high-value-added products such as banknotes and financial bills. By printing fluorescent inks (especially colorless fluorescent inks), a printed pattern can be formed that can be quickly identified as authentic by ultraviolet light sources or machines. Therefore, colorless fluorescent printed patterns are also the most commonly used anti-counterfeiting method. However, with the spread of colorless fluorescent materials and ink technology, the traditional anti-counterfeiting ability achieved by printing colorless fluorescent inks has been significantly weakened.

[0003] In the field of optical anti-counterfeiting, anti-counterfeiting features such as dynamic and embossed are being used more and more widely. Common dynamic anti-counterfeiting effects include pattern rolling, rotation, scaling, depth effects (such as floating, sinking, etc.) and switching between different patterns. The imitation of such anti-counterfeiting effects is also increasing, making the anti-counterfeiting ability of anti-counterfeiting elements worse and worse. Both optical anti-counterfeiting structures with dynamic and embossed anti-counterfeiting effects need to be realized through ultraviolet light curing molding (also known as UV molding). However, traditional printed colorless fluorescent inks are large in size (not less than 6 microns), and cannot be replicated and molded at the micro-nano level with optical anti-counterfeiting structures (such as microstructures of 4 microns), and cannot take into account both ultraviolet light response and dynamic and embossed anti-counterfeiting effects.

[0004] That is to say, the anti-counterfeiting element in the prior art has the problem of poor anti-counterfeiting ability. Summary of the invention

[0005] The main purpose of the present invention is to provide an ultraviolet light responsive anti-counterfeiting element and a preparation method thereof, so as to solve the problem that the anti-counterfeiting ability of the anti-counterfeiting element in the prior art is poor.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided an anti-counterfeiting element responsive to ultraviolet light, comprising: a substrate, which is a transparent material; an optical structure area, which is filled with colorless fluorescent material, and is arranged on one side surface of the substrate, and at least a part of the optical structure area has a micro-nano structure area with surface undulations, so that the optical structure area produces a relief anti-counterfeiting effect and / or a dynamic anti-counterfeiting effect; a covering layer, at least a part of the covering layer is arranged on a side surface of the optical structure area away from the substrate; when the light source is ultraviolet light, the optical structure area can be observed to produce a relief anti-counterfeiting effect and / or a dynamic anti-counterfeiting effect with an anti-counterfeiting color on the outside of the substrate and / or the outside of the covering layer.

[0007] Further, the covering layer includes one of a covering plating layer, a covering coating layer, and a combination layer formed by a covering plating layer and a covering coating layer.

[0008] Furthermore, the covering layer is a covering coating, which is arranged in the same shape on the optical structure area. The embossed anti-counterfeiting effect and / or the dynamic anti-counterfeiting effect can be observed on the outside of the substrate and the outside of the covering coating. When ultraviolet light irradiates the anti-counterfeiting element that responds to ultraviolet light, the anti-counterfeiting color can only be observed on the outside of the substrate.

[0009] Furthermore, the covering coating includes at least one of a metal coating, a photo-variable coating with a Fabry-Perot structure, and a coating formed by combining the metal coating and the photo-variable coating with a Fabry-Perot structure.

[0010] Furthermore, the covering layer is a covering coating, and the surface of the covering coating on one side away from the substrate is arranged parallel to the extension direction of the substrate, and the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect will be hidden and cannot be observed under ambient light. Only when ultraviolet light irradiates the anti-counterfeiting element that responds to ultraviolet light, the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect or the combination of the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect with anti-counterfeiting color can be observed on the outside of the substrate and the outside of the covering coating.

[0011] Furthermore, the covering coating is an organic transparent material, and the difference between the refractive index of the material in the optical structure area and the refractive index of the organic transparent material is less than or equal to 0.35. It should be noted that only when the refractive index difference is small enough (less than or equal to 0.35), can the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect be hidden and cannot be observed. The covering coating should completely cover the ups and downs of the anti-counterfeiting structure, so that the above-mentioned embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect are hidden and cannot be observed.

[0012] Furthermore, the covering layer is a combined layer, at least a portion of the combined layer has a covering coating, the covering coating is isomorphically arranged on the optical structure area, at least another portion of the combined layer has a covering coating, the covering coating covers the covering coating and the optical structure area, and a surface of the covering coating on one side away from the optical structure area is arranged parallel to the extension direction of the substrate.

[0013] Furthermore, the micro-nano structure area has a plurality of anti-counterfeiting structures, and the particle size of the colorless fluorescent material is smaller than the minimum value of the characteristic size of the anti-counterfeiting structure.

[0014] Furthermore, the minimum value of the characteristic dimension of the anti-counterfeiting structure is greater than or equal to 300 nm; and / or the particle size of the colorless fluorescent material is less than 200 nm.

[0015] Furthermore, when the wavelength of the ultraviolet light is greater than or equal to 240 nm and less than or equal to 400 nm, the optical structure area produces an anti-counterfeiting color in response to the ultraviolet light.

[0016] Furthermore, the micro-nano structure area includes at least one of a micro-mirror, a micro-prism, a Fresnel structure and a sinusoidal holographic structure.

[0017] Furthermore, the UV-light-responsive anti-counterfeiting element has a plurality of optical structure areas, and the plurality of optical structure areas are arranged at intervals.

[0018] Furthermore, at least two of the multiple optical structure areas are filled with different colorless fluorescent materials.

[0019] According to another aspect of the present invention, a preparation method for preparing an anti-counterfeiting element that responds to ultraviolet light is provided. The preparation method is used to prepare the above-mentioned anti-counterfeiting element that responds to ultraviolet light, and the preparation method includes: selecting a colorless fluorescent material that can respond to ultraviolet light; selecting a liquid material for forming an optical structure area of ​​the anti-counterfeiting element that responds to ultraviolet light; dissolving the colorless fluorescent material in the liquid material to form a molded material; selecting a substrate of the anti-counterfeiting element that responds to ultraviolet light; setting the molded material on the substrate; processing the molded material to form an optical structure area by ultraviolet light curing molding; and processing a covering layer of the anti-counterfeiting element that responds to ultraviolet light from a side of the optical structure area away from the substrate.

[0020] Furthermore, the molding material is disposed on the substrate by coating or printing.

[0021] Furthermore, the covering layer is a covering coating, and in the process of processing the covering layer of the UV-responsive anti-counterfeiting element from the side of the optical structure area away from the substrate, it includes: evaporating the covering coating on the optical structure area.

[0022] Furthermore, the covering layer is a covering coating, and in the process of processing the covering layer of the UV-responsive anti-counterfeiting element from the side of the optical structure area away from the substrate, it includes: processing the covering coating on the optical structure area by coating or printing.

[0023] Furthermore, the covering layer is a composite layer formed by a covering plating layer and a covering coating layer. In the process of processing the covering layer of the ultraviolet light responsive anti-counterfeiting element from the side of the optical structure area away from the substrate, it includes: evaporating the covering plating layer on the optical structure area; removing at least a portion of the covering plating layer by hollowing out; processing the covering coating layer on the optical structure area or the covering plating layer by coating or printing.

[0024] Furthermore, the UV-responsive anti-counterfeiting element has a plurality of optical structure areas, and the plurality of optical structure areas use the same molded material. The process of setting the molded material on the substrate includes: printing the molded material on the substrate.

[0025] Furthermore, the ultraviolet light responsive anti-counterfeiting element has multiple optical structure areas, at least two of the multiple optical structure areas use different colorless fluorescent materials, and the process of setting the molded material on the substrate includes: setting the molded material containing different colorless fluorescent materials on the substrate at intervals by overprinting.

[0026] Applying the technical scheme of the present invention, the ultraviolet light responsive anti-counterfeiting element includes a substrate, an optical structure area and a covering layer, the substrate is a transparent material; the optical structure area is filled with colorless fluorescent material, the optical structure area is arranged on one side surface of the substrate, at least a part of the optical structure area has a micro-nano structure area with surface undulations, so that the optical structure area produces a relief anti-counterfeiting effect and / or a dynamic anti-counterfeiting effect; at least a part of the covering layer is arranged on a side surface of the optical structure area away from the substrate; when the light source is ultraviolet light, the ultraviolet light responsive anti-counterfeiting element, a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect or a combination of the relief anti-counterfeiting effect or the dynamic anti-counterfeiting effect with an anti-counterfeiting color can be observed on the outside of the substrate or the outside of the covering layer, or on the outside of the substrate and the outside of the covering layer.

[0027] By adding colorless fluorescent materials to the optical structure area, it can emit fluorescence with a specific color under ultraviolet light. In combination with the undulating micro-nano structure area, the fluorescence is modulated by the optical structure area to form a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect, or a combination of the relief anti-counterfeiting effect and the dynamic anti-counterfeiting effect, thereby enhancing the anti-counterfeiting effect. At the same time, since the fluorescence of a specific color is used as the anti-counterfeiting color, the anti-counterfeiting effect is enriched and it is not easy to be forged. By setting a covering layer on the optical structure area, the observation conditions of the anti-counterfeiting feature can be limited, and it can be hidden under ambient light, visible under ultraviolet light, and different observation effects can be achieved on the outside of the substrate or the outside of the covering layer under ultraviolet light, which has stronger anti-counterfeiting properties without affecting the recognition of the anti-counterfeiting feature. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 A cross-sectional view of an anti-counterfeiting element responsive to ultraviolet light according to a first embodiment of the present invention is shown;

[0030] Figure 2 Shows Figure 1 Schematic diagram of the effect of the anti-counterfeiting element observed from the outside of the covering layer under ultraviolet light;

[0031] Figure 3 Shows Figure 1 Schematic diagram of the effect of the anti-counterfeiting element observed from the outside of the substrate under ultraviolet light;

[0032] Figure 4 A cross-sectional view of an anti-counterfeiting element responsive to ultraviolet light according to a second embodiment of the present invention is shown;

[0033] Figure 5 Shows Figure 4 Schematic diagram of the effect of observing the anti-counterfeiting element under ultraviolet light;

[0034] Figure 6 A cross-sectional view of an anti-counterfeiting element responsive to ultraviolet light according to a third embodiment of the present invention is shown;

[0035] Figure 7 Shows Figure 6 Schematic diagram of the effect of the anti-counterfeiting element observed from the outside of the covering layer under ultraviolet light;

[0036] Figure 8 Shows Figure 6 Schematic diagram of the effect of the anti-counterfeiting element observed from the outside of the substrate under ultraviolet light;

[0037] Fig. 9 A cross-sectional view of an anti-counterfeiting element responsive to ultraviolet light according to a fourth embodiment of the present invention is shown;

[0038] Fig.10 Shows Fig. 9 Schematic diagram of the effect of observing the anti-counterfeiting element under ultraviolet light;

[0039] Fig.11 A cross-sectional view of an anti-counterfeiting element responsive to ultraviolet light according to a fifth embodiment of the present invention is shown;

[0040] Fig.12 Shows Fig.11 Schematic diagram of the effect of observing the anti-counterfeiting element under ultraviolet light;

[0041] Fig.13 A flow chart showing a method for preparing an ultraviolet light responsive anti-counterfeiting element of the present invention is shown.

[0042] The above drawings include the following reference numerals:

[0043] 10. Substrate; 20. Optical structure area; 21. Micro-nano structure area; 22. Anti-counterfeiting structure; 23. Background area; 30. Covering layer; 31. Covering coating; 32. Covering coating; 33. Combined layer. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0045] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0046] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0047] In order to solve the problem of poor anti-counterfeiting ability of anti-counterfeiting elements in the prior art, the present invention provides an ultraviolet light responsive anti-counterfeiting element and a preparation method thereof.

[0048] like Figures 1 to 13 As shown, the ultraviolet light responsive anti-counterfeiting element includes a substrate 10, an optical structure area 20 and a covering layer 30, the substrate 10 is a transparent material; the optical structure area 20 is filled with colorless fluorescent material, the optical structure area 20 is arranged on one side surface of the substrate 10, and at least a part of the optical structure area 20 has a micro-nano structure area 21 with a surface undulation, so that the optical structure area 20 produces a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect or a combination of the relief anti-counterfeiting effect or the dynamic anti-counterfeiting effect; at least a part of the covering layer 30 is arranged on the side surface of the optical structure area 20 away from the substrate 10; when the light source is ultraviolet light to irradiate the ultraviolet light responsive anti-counterfeiting element, a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect or a combination of the relief anti-counterfeiting effect or the dynamic anti-counterfeiting effect with an anti-counterfeiting color can be observed on the outside of the substrate 10 or the outside of the covering layer 30, or on the outside of the substrate 10 and the outside of the covering layer 30.

[0049] By adding colorless fluorescent material to the optical structure area 20, it can emit fluorescence with a specific color under ultraviolet light irradiation, and cooperate with the micro-nano structure area 21 with undulating surface, so that the fluorescence is modulated by the optical structure area 20 to form a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect, or the relief anti-counterfeiting effect and the dynamic anti-counterfeiting effect are combined to enhance the anti-counterfeiting effect. At the same time, since the fluorescence of a specific color is used as an anti-counterfeiting color, the anti-counterfeiting effect is enriched and it is not easy to be forged. By arranging a covering layer 30 on the optical structure area 20, the observation conditions of the anti-counterfeiting feature can be limited, and it can be hidden under ambient light, visible under ultraviolet light, and the outside of the substrate 10 or the outside of the covering layer 30 under ultraviolet light can be observed differently, which has a stronger anti-counterfeiting property without affecting the recognition of the anti-counterfeiting feature.

[0050] It should be noted that, in the ultraviolet light irradiation anti-counterfeiting elements mentioned in the present application and the effects observed on the outside of the substrate 10 or the outside of the covering layer 30, the ultraviolet light irradiation and the observation of the effects are both located on the same side of the anti-counterfeiting elements, that is, if ultraviolet light is used for irradiation on the outside of the substrate 10, the effect is also observed on the outside of the substrate 10, and if ultraviolet light is used for irradiation on the outside of the covering layer 30, the effect is also observed on the outside of the covering layer 30.

[0051] like Fig.13 As shown, the present invention also provides a preparation method for preparing an anti-counterfeiting element responsive to ultraviolet light, the preparation method is used to prepare the anti-counterfeiting element responsive to ultraviolet light of the present application, and the preparation method includes: selecting a colorless fluorescent material that can respond to ultraviolet light; selecting a liquid material for forming an optical structure area 20 of the anti-counterfeiting element responsive to ultraviolet light; dissolving the colorless fluorescent material in the liquid material to form a molded material; selecting a substrate 10 of the anti-counterfeiting element responsive to ultraviolet light; setting the molded material on the substrate 10; processing the molded material to form the optical structure area 20 by ultraviolet light curing molding; and processing the covering layer 30 of the anti-counterfeiting element responsive to ultraviolet light from the side of the optical structure area 20 away from the substrate 10. The optical structure area 20 is formed by dissolving the colorless fluorescent material in the liquid material forming the optical structure area 20, and the molded material can be formed into the optical structure area 20 by ultraviolet light curing molding, so that the optical structure area 20 is filled with colorless fluorescent material, so that the fluorescent color generated by the optical structure area 20 under ultraviolet light is combined with the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect. While improving the anti-counterfeiting ability, the preparation method has the advantages of high efficiency, stability, and mass production, and can meet the requirements of industrial production.

[0052] It should be noted that when the colorless fluorescent material is dissolved in the liquid material to form the molding material, the dissolution includes physical dispersion and chemical reaction dissolution, but it does not affect the effect of generating fluorescent color under ultraviolet light irradiation.

[0053] Specifically, the micro-nano structure area 21 has a plurality of anti-counterfeiting structures 22, and the particle size of the colorless fluorescent material is smaller than the minimum value of the characteristic size of the anti-counterfeiting structure 22. This arrangement enables the colorless fluorescent material to be filled in the anti-counterfeiting structure 22, so that the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect can be combined with the anti-counterfeiting color.

[0054] It should be noted that the minimum value of the characteristic size of the anti-counterfeiting structure 22 in the present application is understood to be the minimum value of the width and height (or depth) of the characteristic unit forming the anti-counterfeiting structure 22.

[0055] Optionally, the characteristic size of the anti-counterfeiting structure 22 is in the range of 0.2-5 microns.

[0056] For example, the minimum characteristic size of a periodically arranged micro-reflector with a height of 2 microns and a width of 4 microns is 2 microns. For non-periodic optical structures, the characteristic size refers to the minimum value of a series of characteristic unit widths and heights (or depths). For example, there are micro-reflectors with a height of 2.5-3.5 microns and a width of 2-4 microns randomly distributed, and their minimum characteristic size is 2 microns. Therefore, for the micro-reflectors with a minimum characteristic size of 2 microns, the particle size of the colorless fluorescent material should be at least less than 2 microns in order to fill the above-mentioned anti-counterfeiting structure 22. If the particle size of the above-mentioned colorless fluorescent material is greater than 2 microns, the anti-counterfeiting structure 22 will not be filled, and the ultraviolet light response embossed anti-counterfeiting effect or dynamic anti-counterfeiting effect or a combination of the two effects brought by the anti-counterfeiting structure 22 cannot be obtained, and only a traditional coating printing effect similar to that of coating colorless fluorescent ink can be obtained. The smaller the particle size of the colorless fluorescent material, the more it can eliminate the granularity brought by the particle size, and the more it can obtain the same shape filling effect consistent with the anti-counterfeiting structure 22. For example, for a micro-reflector with a minimum characteristic size of 2 microns, a good uniform filling effect can be obtained when the particle size is 200nm. If the particle size of the colorless fluorescent material is 1.9 microns, it can be filled, but the uniform filling effect is not as consistent as 200nm.

[0057] Preferably, the minimum value of the characteristic size of the anti-counterfeiting structure 22 is greater than or equal to 300nm, and the particle size of the colorless fluorescent material is less than 200nm. The above particle size can achieve the filling of the anti-counterfeiting structure 22. At the same time, when the particle size is half of the wavelength of visible light, that is, when the particle diameter of the colorless fluorescent material is 200-500nm, the scattering ability of light is the strongest, which can lead to high hiding power but not transparency. Therefore, the particle size of the colorless fluorescent material should be less than this value to achieve good transparency. It should be noted that for the case of a wide particle size distribution, a particle size less than 200nm means that particles with a particle size less than 200nm account for 90%, that is, D90 should be less than 200nm. More advantageously, the particle size is less than 60nm, which can achieve a more favorable filling of the anti-counterfeiting structure 22. The most advantageous thing is that the colorless fluorescent material can be completely dissolved in the liquid material used for ultraviolet light curing molding, so that the particle size cannot be detected. The above particle size can be obtained by detecting the liquid material used for ultraviolet light curing molding after the colorless fluorescent material is dissolved or dispersed through a mature particle size analyzer. The narrow particle size distribution can also be obtained by detecting the optical structure area 20 after UV curing through instruments such as electron microscope, laser particle size analyzer, light scattering, etc.

[0058] Among them, the colorless fluorescent material can be composed of an organic material, an inorganic material, an organic-inorganic hybrid material, or a mixed material of organic and inorganic materials. The colorless fluorescent material can be excited by ultraviolet light of 240-400nm to produce fluorescence of a specific color that can be observed. Preferably, the colorless fluorescent material can respond to luminescence under 365nm ultraviolet light. Such materials have been fully disclosed in existing patents and professional materials. BASF, Nemoto and other companies have provided a large number of application guidelines and basic data for such fluorescent materials. Liquid materials suitable for ultraviolet light curing molding have been disclosed more fully in some patents and professional books. Such ultraviolet light curing material systems include free radical-cured acrylates, acrylamides and cation-cured epoxies, vinyl ethers and oxetanes. Among them, acrylate and acrylamide systems are preferred. The above-mentioned colorless fluorescent materials need to be fully dissolved or dispersed in the liquid material used for ultraviolet light curing molding to meet the particle size requirements for filling the anti-counterfeiting structure 22. For colorless fluorescent materials, organic fluorescent materials are preferred; more preferably, organic fluorescent materials with good solubility in acrylate systems.

[0059] Specifically, when the wavelength of ultraviolet light is greater than or equal to 240nm and less than or equal to 400nm, the optical structure area 20 responds to the ultraviolet light to produce anti-counterfeiting color. In other words, ultraviolet light wavelengths in the range of 240nm to 400nm can cover various colorless fluorescent materials applicable to the present application to emit anti-counterfeiting colors.

[0060] Specifically, the micro-nano structure area 21 includes at least one of a micro-mirror, a micro-prism, a Fresnel structure and a sinusoidal holographic structure. Various choices of the micro-nano structure area 21 can obtain different embossed anti-counterfeiting effects or dynamic anti-counterfeiting effects.

[0061] It should be noted that the undulating structure of the micro-nano structure area 21 can be formed by ultraviolet curing molding. The embossed anti-counterfeiting effect or dynamic anti-counterfeiting effect formed by the above-mentioned undulating structure has been disclosed by patents. Typical dynamic anti-counterfeiting effects include the translation, rotation, scaling of patterns and texts, depth effects (such as floating, sinking, etc.), and switching of different patterns and texts. Typical embossed anti-counterfeiting effects include the convex and concave three-dimensional embossed feeling and 3D stereoscopic effect of the anti-counterfeiting structure 22. The above-mentioned embossed anti-counterfeiting effect and dynamic anti-counterfeiting effect can be combined, such as forming a 3D three-dimensional rotation effect, a homotopic anomaly effect (multiple complete patterns can be seen at different angles at the same position), and two or more combinations of white dynamic effects (dynamic light and dark effects presented with the viewing angle) such as the dynamic light and dark change effect combined with scrolling and scaling.

[0062] Specifically, the covering layer 30 includes one of a covering plating layer 31, a covering coating layer 32, and a combined layer 33 formed by the covering plating layer 31 and the covering coating layer 32. It should be noted that the covering layer 30 can be patterned to form specific text or patterns, so as to have a strong combined anti-counterfeiting ability.

[0063] The effects that can be achieved by different covering layers 30 will be described below in conjunction with different embodiments.

[0064] Embodiment 1

[0065] like Figures 1 to 3 As shown, when the covering layer 30 is a covering coating 31, the covering coating 31 is disposed in the same shape on the optical structure area 20, and a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect or a combination of the two effects can be observed on the outside of the substrate 10 and the outside of the covering coating 31. When ultraviolet light irradiates the anti-counterfeiting element that responds to ultraviolet light, the anti-counterfeiting color can only be observed on the outside of the substrate 10. In other words, the morphological characteristics of the surface of the side of the covering coating 31 away from the optical structure area 20 are the same as those of the optical structure area 20, and because the substrate 10 is also transparent, the reflection effect of the covering coating 31 on light enables the relief anti-counterfeiting effect or the dynamic anti-counterfeiting effect or a combination of the two effects to be formed on the outside of the substrate 10 and the outside of the covering coating 31 under ambient light and under the irradiation of ultraviolet light. However, under the irradiation of the ultraviolet light source, due to the obstruction of the covering coating 31, the embossed anti-counterfeiting effect with anti-counterfeiting color or the dynamic anti-counterfeiting effect or the combination of the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect cannot be observed on the outside of the covering coating 31, and can only be observed on the outside of the substrate 10.

[0066] Specifically, the covering coating 31 includes at least one of a metal coating, a photovariable coating with a Fabry-Perot structure, and a coating formed by combining a metal coating and a photovariable coating with a Fabry-Perot structure, so as to achieve a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect or a combination of the two effects to enrich the anti-counterfeiting features.

[0067] It should be noted that the cover coating 31 is disposed on the optical structure area 20 in the same shape, so that the surface morphology of the cover coating 31 can maintain the surface morphology characteristics of the optical structure area 20. The metal coating can be selected from aluminum, chromium, copper or alloy. The optically variable coating can be selected from a laminated structure having a Fabry-Perot structure. The typical structure of the optically variable coating of the Fabry-Perot structure is "reflection layer / isolation layer / absorption layer", such as Cr / MgF2 / Al.

[0068] Specifically, the covering layer 30 is a covering coating 31 . The process of processing the covering layer 30 of the UV-responsive anti-counterfeiting element on the surface of the optical structure area 20 away from the substrate 10 includes: evaporating the covering coating 31 on the optical structure area 20 .

[0069] like Figure 1 As shown, the substrate 10 is a colorless and transparent PET material, and the optical structure area 20 is processed on the PET, including a micro-nano structure area 21 of "number 10" forming a three-dimensional relief anti-counterfeiting effect. The micro-nano structure area 21 is realized by a holographic structure, and the minimum characteristic size of the holographic structure forming the relief anti-counterfeiting effect is 300nm. The optical structure area 20 also includes a background area 23, which is composed of a micro-mirror structure forming a rolling effect, and the minimum characteristic size is 2μm. The colorless fluorescent material is a quinazoline organic matter, which can produce red fluorescence under 395nm ultraviolet light (the peak spectrum of the fluorescence is 615nm). The colorless fluorescent material can be completely dissolved in a 100% solid UV liquid acrylamide / acrylate mixed material (containing 2% of the photoinitiator: diphenyl-(2,4,6-trimethylbenzoyl) oxyphosphine) to form a molding material. After the above molding material is coated, the optical structure area 20 is formed by UV molding (ultraviolet light curing molding). An aluminum coating is formed on the optical structure area 20 by vapor deposition, and then the micro-nano structure area 21 of the "number 10" with a three-dimensional embossed anti-counterfeiting effect is protected by overprinting and printing an aluminum-free protective layer. The aluminum coating in the area outside the "number 10" is removed by alkali washing, and then a gold-to-green photovariable coating is vapor deposited (the stacked structure vapor-deposited in sequence is Cr / MgF2 / Al, with aluminum on the outermost side), and finally a covering coating 31 is formed, thereby obtaining the ultraviolet light responsive optical anti-counterfeiting element of this embodiment.

[0070] In this embodiment, under sunlight and common lighting sources (ambient light), a silvery white (aluminum coating color) embossed anti-counterfeiting effect "number 10" can be observed from the outside of the substrate 10, and the area outside the "number 10" forms a zooming and rolling effect centered on the "number 10" and the color changes from gold to green; the colors observed from the outside of the covering coating 31 are all silvery white (the outermost color is the aluminum coating) and the embossed anti-counterfeiting effect of the "number 10" and the zooming and rolling effect of the area outside the "number 10". Under 395nm ultraviolet light, as Figure 2 As shown, when observed from the outside of the covering coating 31, the fluorescent color cannot be observed due to the obstruction of the covering coating 31; Figure 3 As shown, the red fluorescent color and the embossed anti-counterfeiting effect of the "number 10" formed by the red fluorescence and the zooming and scrolling effects of the area outside the "number 10" can be observed from the outside of the substrate 10.

[0071] Embodiment 2

[0072] like Figures 4 to 5 As shown, the difference from the first embodiment is that the materials and structures of the optical structure area 20 and the cover layer 30 are different.

[0073] Specifically, when the covering layer 30 is a covering coating 32, the surface of the covering coating 32 on one side away from the substrate 10 is arranged parallel to the extension direction of the substrate 10. Only when the ultraviolet light irradiates the anti-counterfeiting element that responds to ultraviolet light, the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect or the combination of the two effects can be observed on the outside of the substrate 10 and the outside of the covering coating 32, and the anti-counterfeiting color can be observed on the outside of the substrate 10 and the outside of the covering coating 32. In other words, there is no undulating morphological feature on the surface of the covering coating 32 on one side away from the optical structure area 20, but it is covered as a plane. Under ambient light, the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect will be hidden and cannot be observed. However, under the irradiation of an ultraviolet light source, the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect or the combination of the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect with anti-counterfeiting color can be observed on the outside of the substrate 10 and the outside of the covering coating 32, which ensures that the anti-counterfeiting feature is recognized and is not easy to be forged, thereby improving the anti-counterfeiting ability.

[0074] Specifically, the covering coating 32 is an organic transparent material, and the difference between the refractive index of the material of the optical structure area 20 and the refractive index of the organic transparent material is less than or equal to 0.35, so as to avoid that when the refractive index difference is too high, the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect cannot be hidden. Preferably, the refractive index of the material of the optical structure area 20 is between 1.35 and 1.7.

[0075] It should be noted that only when the refractive index difference is small enough (less than or equal to 0.35), the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect can be hidden and cannot be observed. The covering coating 32 should completely cover the undulations of the anti-counterfeiting structure 22, so that the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect are hidden and cannot be observed.

[0076] It should be noted that the covering coating 32 can be processed on the surface of the optical structure area 20 by coating or printing with an organic coating. By controlling the coating or printing thickness to be greater than the height of the surface convex and concave of the optical structure area 20, the original surface structure undulations can be eliminated, that is, non-isomorphic coverage is achieved, which means that the surface morphology of the covering coating 32 cannot maintain the surface morphology characteristics of the optical structure area 20. The above-mentioned organic transparent material can be a water-based coating, a UV coating, and a solvent-based coating, and a large number of such products are available in the market to meet the requirements. When the refractive index of the optical structure area 20 and the covering coating 32 is not much different, the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect or the combination of the two effects formed by the optical structure area 20 cannot be observed.

[0077] Specifically, in the process of processing the covering layer 30 of the UV-responsive anti-counterfeiting element on the surface of the optical structure area 20 away from the substrate 10, it includes: processing the covering coating 32 on the optical structure area 20 by coating or printing.

[0078] like Figure 4As shown, the substrate 10 is a colorless and transparent PET material, and the optical structure area 20 is processed on the PET, including a micro-nano structure area 21 of the "number 10" with a zooming effect (shrinking or enlarging with the change of the observation angle) and a background area 23 outside the micro-nano structure area 21. The background area 23 is a flat area. The micro-nano structure area 21 is realized by a micro-mirror structure, and the minimum value of the characteristic size of the micro-mirror structure is 1.5μm. The colorless fluorescent material is an inorganic material and can produce blue fluorescence under 365nm ultraviolet light (the peak value of the fluorescence spectrum is 450nm). The colorless fluorescent material can be dispersed in a 100% solid UV liquid acrylate material (containing 2% of the photoinitiator: diphenyl-(2,4,6-trimethylbenzoyl) phosphine) to form a molded material, and the D90 is 190nm, that is, the particles with a particle size less than 190nm account for 90%. The above-mentioned molded material (refractive index is 1.7) forms the optical structure area 20 by UV molding. A solvent-based organic fluorine coating is coated on the surface of the optical structure area 20, and the solvent is dried in a drying oven to form a flat surface of a covering coating 32 (the refractive index of the covering coating 32 is 1.35), thereby obtaining the ultraviolet light responsive optical anti-counterfeiting element of this embodiment.

[0079] In this embodiment, under sunlight and common lighting sources (ambient light), the optical anti-counterfeiting element is colorless and transparent when observed from the outside of the substrate 10 and the outside of the covering coating 32, and the "number 10" cannot be observed. Figure 5 As shown, the blue fluorescent “number 10” with a zoom effect and the blue fluorescent area outside the “number 10” can be observed from the outside of the covering coating 32 or the outside of the substrate 10 .

[0080] Embodiment 3

[0081] like Figures 6 to 8 As shown, the difference from the first embodiment is that the materials and structures of the optical structure area 20 and the cover layer 30 are different.

[0082] Specifically, when the covering layer 30 is a combined layer 33, at least a portion of the combined layer 33 has a covering coating 31, the covering coating 31 is disposed on the optical structure area 20 in the same shape, and at least another portion of the combined layer 33 has a covering coating 32, the covering coating 32 covers the covering coating 31 and the optical structure area 20, and the surface of the covering coating 32 on one side away from the optical structure area 20 is disposed parallel to the extension direction of the substrate 10. That is, the covering coating 31 covers at least a portion of the optical structure area 20, and the covering coating 32 covers the covering coating 31 and the surface of the optical structure area 20 not covered by the covering coating 31. Such an arrangement can obtain a complex anti-counterfeiting effect such as the combination of the first embodiment and the second embodiment.

[0083] For example, the area where the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect or the combination of the two effects that responds to ultraviolet light is partially covered by the covering coating 31 and partially covered by the covering coating 32. When ultraviolet light is not used for irradiation, the anti-counterfeiting effect of the area covered by the covering coating 32 is hidden, and the anti-counterfeiting effect covered by the covering coating 31 can be observed. When ultraviolet light irradiates the optical structure area 20, the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect or the combination of the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect with anti-counterfeiting color can be observed from the outside of the substrate 10, while from the outside of the combined layer 33, only the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect or the combination of the embossed anti-counterfeiting effect or the dynamic anti-counterfeiting effect with anti-counterfeiting color can be observed in the area covered by the covering coating 32, and the fluorescent effect of the area of ​​the covering coating 31 is covered.

[0084] like Figure 6 As shown, the substrate 10 is a colorless and transparent PVC material, and the optical structure area 20 is processed on the PVC. The optical structure area 20 is a micro-mirror structure that forms a relative rolling effect, and the minimum characteristic size is 1.5μm. The colorless fluorescent material is a benzoxazine organic substance, which can produce green fluorescence under 395nm ultraviolet light (the spectral peak of the fluorescence is 510nm). The colorless fluorescent material can be completely dissolved in a 100% solid UV liquid acrylamide material (containing 2% of the photoinitiator: diphenyl-(2,4,6-trimethylbenzoyl) oxyphosphine), and the particle size cannot be measured. The above material (refractive index is 1.5) is formed into the optical structure area 20 by UV molding. Then, the "number 10" is printed by overprinting a water-soluble copper removal layer, that is, after evaporating metal copper, the copper in the "number 10" area is removed by water washing, and then a UV coating (refractive index is 1.5) is further coated to form a combined layer 33, and finally the ultraviolet light responsive optical anti-counterfeiting element of this embodiment is obtained. That is to say, the micro-nano structure area 21 where the "number 10" is located and the background area 23 except the "number 10" are both composed of micro-mirrors. The micro-nano structure area 21 is only covered with a covering coating 32 formed by a UV coating, and the background area 23 is first covered with a covering coating 31 formed by a copper plating layer, and the covering coating 31 is covered with a covering coating 32.

[0085] Specifically, in the process of processing the covering layer 30 of the ultraviolet light responsive anti-counterfeiting element on the surface of the optical structure area 20 away from the substrate 10, it includes: evaporating the covering coating 31 on the optical structure area 20; removing at least a portion of the covering coating 31 by hollowing out; processing the covering coating 32 on the optical structure area 20 or the covering coating 31 by coating or printing.

[0086] In this embodiment, under sunlight and a common lighting source (ambient light), a colorless and transparent "number 10" and a golden color (copper plating color) with a rolling effect in the area except the "number 10" can be observed from the outside of the substrate 10 and the outside of the cover coating 32. Figure 7 As shown, the green fluorescence and rolling effect of the "number 10" are observed from the outside of the covering coating 31, and the other areas have no green fluorescence effect but only the gold color (the color of the copper coating) of the rolling effect; Figure 8 As shown, green fluorescence can be observed on the outer side of the substrate 10 and a rolling effect can be seen.

[0087] It should be noted that the ultraviolet-responsive optical structure area 20 in the present application is colorless and transparent and contains a colorless fluorescent material that responds to ultraviolet light. Within the scope of the present application, the expression "colorless" is understood to mean that when an observer observes the target color through the colorless layer described in the ultraviolet-responsive anti-counterfeiting element of the present application, the original color of the target can be observed. The material itself should be colorless or its own chromaticity should be weak enough so that it does not affect the observation of the target color after the colorless layer is formed by processing, and the target color will not undergo obvious changes visible to the naked eye due to the colorless layer. Specifically, it can be understood that the original color of the covering coating 31 can be observed through the colorless ultraviolet-responsive optical structure area 20, and the original ultraviolet-excited fluorescent color can be observed through the colorless covering coating 32. Within the scope of the present application, a "transparent" material is understood to be such a material that the incident electromagnetic radiation (at least within the visible wavelength of about 380nm to about 780nm) can basically pass through the "transparent" material. The "transparent" material in the present application should have a transmittance of not less than 70%.

[0088] It should be noted that ultraviolet light curing molding (UV molding) is widely used in the mass production of complex optical structures, with good replication performance and stable process. Evaporated metal coatings and Fabry-Perot structured optically variable coatings have mature and reliable processes and equipment, and have achieved large-scale production. Hollowing methods include the most mature printing hollowing, as well as precise hollowing combined with microstructures. The most mature printed hollowing in industrial applications can be divided into alkali-washing / acid-washing hollowing, water-washing hollowing, etc. Water-washing hollowing is achieved by printing a water-soluble hollowing coating, then evaporating the coating, and then removing the water-soluble coating and coating by washing to form patterns and numbers. Alkali-washing / acid-washing hollowing is achieved by removing the coating of the non-protected area by printing a protective coating through alkali or acid to achieve patterning. The equipment involved in the above-mentioned alkali-washing and water-washing hollowing is very mature. The combination of the above-mentioned hollowing means and evaporation means can form the effect of a variety of coating combinations.

[0089] Embodiment 4

[0090] like Fig. 9 and Fig.10As shown, the difference from the second embodiment is that the anti-counterfeiting element responsive to ultraviolet light has a plurality of optical structure areas 20, and the plurality of optical structure areas 20 are arranged at intervals.

[0091] like Fig. 9 As shown, the substrate 10 is a colorless and transparent PET material, and two optical structure areas 20 are processed on the PET by printing to form two "numbers 10" with a gap. The "number 10" is processed by UV molding to have a scaling effect (shrinking or enlarging with the change of the observation angle). The optical structure area 20 is a micro-nano structure area 21, which is realized by a micro-mirror structure, and the minimum value of the characteristic size of the micro-mirror structure is 1.5μm. The colorless fluorescent material is an inorganic material that can produce blue fluorescence under 365nm ultraviolet light (the peak value of the fluorescence spectrum is 450nm). The colorless fluorescent material can be dispersed in a 100% solid UV liquid acrylate material (containing 2% of a photoinitiator: diphenyl-(2,4,6-trimethylbenzoyl) oxyphosphine) to form a molding material, and the D90 is 190nm, that is, the particles with a particle size less than 190nm account for 90%. After the molding material is printed on the substrate 10, it is UV molded to form the optical structure area 20 (refractive index is 1.7). A solvent-based organic fluorine coating is applied to the side of the optical structure area 20 away from the substrate 10, and the solvent is dried by a drying oven to form a flat coating surface, i.e., a covering layer 30, the refractive index of which is 1.35, wherein the covering layer 30 contacts the surface of the optical structure area 20 and the surface of the substrate 10 exposed in the interval between the two optical structure areas 20. Finally, the UV-responsive anti-counterfeiting element of this embodiment is obtained.

[0092] It should be noted that the anti-counterfeiting structures 22 are all provided on the two optical structure areas 20 in this embodiment.

[0093] like Fig.10 As shown, under sunlight and common lighting sources (ambient light), the UV-responsive anti-counterfeiting element of this embodiment is colorless and transparent when observed from the outside of the substrate 10 and the outside of the cover layer 30, and the "number 10" cannot be observed. Under 365nm UV light, two blue fluorescent "numbers 10" with a zoom effect can be observed from the outside of the substrate 10 and the outside of the cover layer 30. In the interval area between the two optical structure areas 20, the above optical effect is not present.

[0094] Embodiment 5

[0095] like Fig.11 and Fig.12 As shown, the difference from the fourth embodiment is that at least two of the multiple optical structure areas 20 are filled with different colorless fluorescent materials.

[0096] like Fig.11As shown, the substrate 10 is a colorless and transparent PET material, and two optical structure areas 20 are processed on the PET by overprinting to form two "numbers 10" with a gap, and the two optical structure areas 20 use different colorless fluorescent materials. The "number 10" is processed by UV molding to have a scaling effect (shrinking or enlarging with the change of the observation angle), and the optical structure area 20 is a micro-nano structure area 21, which is realized by a micro-mirror structure, and the minimum value of the characteristic size of the micro-mirror structure is 1.5μm.

[0097] Among them, one of the two colorless fluorescent materials is an inorganic material, which can produce blue fluorescence (the peak spectrum of the fluorescence is 450nm) under ultraviolet light of 365nm. The blue fluorescent material can be dispersed in a 100% solid UV liquid acrylate material (containing 2% of a photoinitiator: diphenyl-(2,4,6-trimethylbenzoyl) phosphine) to form a molding material, and D90 is 190nm, that is, particles with a particle size of less than 190nm account for 90%;

[0098] The other of the two colorless fluorescent materials is a quinazoline organic substance, which can produce red fluorescence under 395nm ultraviolet light (the peak of the fluorescence spectrum is 615nm). The red colorless fluorescent material can be completely dissolved in a 100% solid UV liquid acrylamide / acrylate mixed material (containing 2% of the photoinitiator: diphenyl-(2,4,6-trimethylbenzoyl) phosphine) to form another molding material.

[0099] The above two molding materials are overprinted on the substrate 10 and then UV molding is performed to form an optical structure area 20 (refractive index is 1.7). A solvent-based organic fluorine coating is applied to the side of the optical structure area 20 away from the substrate 10, and the solvent is dried by a drying oven to form a flat coating surface, i.e., a covering layer 30. The covering layer 30 has a refractive index of 1.35, wherein the covering layer 30 contacts the surface of the optical structure area 20 and the surface of the substrate 10 exposed in the interval between the two optical structure areas 20. Finally, the UV-responsive anti-counterfeiting element of this embodiment is obtained.

[0100] It should be noted that the anti-counterfeiting structures 22 are all provided on the two optical structure areas 20 in this embodiment.

[0101] like Fig.12 As shown, under sunlight and common lighting sources (ambient light), the UV-responsive anti-counterfeiting element of this embodiment is colorless and transparent when observed from the outside of the substrate 10 and the outside of the cover layer 30, and the "number 10" cannot be observed. Under 365nm UV light, two blue fluorescent "number 10" and red fluorescent "number 10" with a zoom effect can be observed from the outside of the substrate 10 and the outside of the cover layer 30. In the interval area between the two optical structure areas 20, the above optical effect is not present.

[0102] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0103] 1. By adding colorless fluorescent material to the optical structure area 20, it can emit fluorescence with a specific color under ultraviolet light, and cooperate with the micro-nano structure area 21 with undulating surface, so that the fluorescence is modulated by the optical structure area 20 to form a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect, or a combination of the relief anti-counterfeiting effect and the dynamic anti-counterfeiting effect, thereby enhancing the anti-counterfeiting effect. At the same time, since the fluorescence of a specific color is used as the anti-counterfeiting color, the anti-counterfeiting effect is enriched and it is not easy to be forged.

[0104] 2. By setting a covering layer 30 on the optical structure area 20, the observation conditions of the anti-counterfeiting features can be limited, so that the anti-counterfeiting features can be hidden under ambient light, visible under ultraviolet light, and the outside of the substrate 10 or the outside of the covering layer 30 under ultraviolet light can be observed differently, thereby having stronger anti-counterfeiting properties without affecting the recognition of the anti-counterfeiting features.

[0105] 3. When the covering layer 30 is the covering coating 31, the morphological features of the surface of the covering coating 31 on the side away from the optical structure area 20 are the same as those of the optical structure area 20, and because the substrate 10 is also transparent, the covering coating 31 reflects light, so that under ambient light and ultraviolet light, the reflected light can form a relief anti-counterfeiting effect or a dynamic anti-counterfeiting effect or a combination of the two effects on the outside of the substrate 10 and the outside of the covering coating 31. However, under the irradiation of the ultraviolet light source, due to the obstruction formed on the outside of the covering coating 31, the anti-counterfeiting color formed by the optical structure area 20 cannot be observed, and the anti-counterfeiting color can only be observed on the outside of the substrate 10.

[0106] 4. When the covering layer 30 is a covering coating 32, the surface of the covering coating 32 on the side away from the optical structure area 20 does not have undulating morphological features, but is covered as a plane. Under ambient light, the embossed anti-counterfeiting effect and the dynamic anti-counterfeiting effect will be hidden and cannot be identified. However, under the irradiation of ultraviolet light, the anti-counterfeiting effect and anti-counterfeiting color can be observed on the outside of the substrate 10 and the outside of the covering coating 32, ensuring that the anti-counterfeiting feature is recognized and is not easy to be forged, thereby improving the anti-counterfeiting ability.

[0107] 5. When the covering layer 30 is a combined layer 33, the covering coating 31 therein covers at least a portion of the optical structure area 20, and the covering coating 32 therein covers the covering coating 31 and the surface of the optical structure area 20 not covered by the covering coating 31 to form a complex anti-counterfeiting effect.

[0108] 6. The covering layer 30 can be patterned to form specific text or patterns, thereby having a strong combined anti-counterfeiting ability.

[0109] 7. The preparation method for preparing ultraviolet light-responsive anti-counterfeiting elements has the advantages of high efficiency, stability, and mass production, and can meet the requirements of industrial production.

[0110] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0111] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0112] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An anti-counterfeiting element responsive to ultraviolet light, characterized in that: include: A substrate (10), wherein the substrate (10) is a transparent material; at least one optical structure area (20), the optical structure area (20) being filled with a colorless fluorescent material, the optical structure area (20) being arranged on a side surface of the substrate (10), and at least a portion of the optical structure area (20) having a micro-nano structure area (21) with a undulating surface, so that the optical structure area (20) produces a relief anti-counterfeiting effect and / or a dynamic anti-counterfeiting effect; A covering layer (30), at least a portion of which is disposed on a surface of the optical structure region (20) that is away from the substrate (10); When ultraviolet light is used as a light source to illuminate the ultraviolet light-responsive anti-counterfeiting element, the optical structure area (20) can be observed on the outside of the substrate (10) and / or the outside of the covering layer (30) to produce the embossed anti-counterfeiting effect with an anti-counterfeiting color and / or the dynamic anti-counterfeiting effect.

2. The UV-responsive anti-counterfeiting element according to claim 1, characterized in that: The covering layer (30) comprises one of a covering plating layer (31), a covering coating layer (32), and a combined layer (33) formed by the covering plating layer (31) and the covering coating layer (32).

3. The UV-responsive anti-counterfeiting element according to claim 2, characterized in that: The covering layer (30) is the covering coating (31), and the covering coating (31) is disposed in the same shape on the optical structure area (20), and the embossed anti-counterfeiting effect and / or the dynamic anti-counterfeiting effect can be observed on the outer side of the substrate (10) and the outer side of the covering coating (31), and when the ultraviolet light irradiates the ultraviolet light-responsive anti-counterfeiting element, the embossed anti-counterfeiting effect and / or the dynamic anti-counterfeiting effect having an anti-counterfeiting color can only be observed on the outer side of the substrate (10).

4. The UV-responsive anti-counterfeiting element according to claim 3, characterized in that: The covering coating (31) comprises at least one of a metal coating, a photo-variable coating with a Fabry-Perot structure, and a coating formed by combining a metal coating and a photo-variable coating with a Fabry-Perot structure.

5. The UV-responsive anti-counterfeiting element according to claim 2, characterized in that: The covering layer (30) is the covering coating (32), and a surface of the covering coating (32) on one side away from the substrate (10) is arranged parallel to the extension direction of the substrate (10), and only when the ultraviolet light irradiates the ultraviolet light-responsive anti-counterfeiting element, the embossed anti-counterfeiting effect and / or the dynamic anti-counterfeiting effect with an anti-counterfeiting color can be observed on the outside of the substrate (10) and the outside of the covering coating (32).

6. The UV-responsive anti-counterfeiting element according to claim 5, characterized in that: The covering coating (32) is an organic transparent material, and the difference between the refractive index of the material of the optical structure area (20) and the refractive index of the organic transparent material is less than or equal to 0.

35.

7. The UV-responsive anti-counterfeiting element according to claim 2, characterized in that: The covering layer (30) is the combined layer (33), at least a portion of the combined layer (33) has the covering coating (31), the covering coating (31) is arranged in the same shape on the optical structure area (20), at least another portion of the combined layer (33) has the covering coating (32), the covering coating (32) covers the covering coating (31) and the optical structure area (20), and a surface of the covering coating (32) on one side away from the optical structure area (20) is arranged parallel to the extension direction of the substrate (10).

8. The UV-responsive anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The micro-nano structure area (21) has a plurality of anti-counterfeiting structures (22), and the particle size of the colorless fluorescent material is smaller than the minimum value of the characteristic size of the anti-counterfeiting structure (22).

9. The UV-responsive anti-counterfeiting element according to claim 8, characterized in that: The minimum value of the characteristic dimension of the anti-counterfeiting structure (22) is greater than or equal to 300 nm; and / or The particle size of the colorless fluorescent material is less than 200 nm.

10. The UV-responsive anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: When the wavelength of the ultraviolet light is greater than or equal to 240 nm and less than or equal to 400 nm, the optical structure area (20) generates the anti-counterfeiting color in response to the ultraviolet light.

11. The UV-responsive anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The micro-nano structure area (21) comprises at least one of a micro-reflector, a micro-prism, a Fresnel structure and a sinusoidal holographic structure.

12. The UV-responsive anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The ultraviolet light responsive anti-counterfeiting element comprises a plurality of the optical structure areas (20), and the plurality of the optical structure areas (20) are arranged at intervals.

13. The UV-responsive anti-counterfeiting element according to claim 12, characterized in that: At least two of the plurality of optical structure regions (20) are filled with different colorless fluorescent materials.

14. A method for preparing an anti-counterfeiting element responsive to ultraviolet light, characterized in that: The preparation method is used to prepare the ultraviolet light responsive anti-counterfeiting element according to any one of claims 1 to 13, and the preparation method comprises: Selecting a colorless fluorescent material that can respond to ultraviolet light; Selecting a liquid material for forming an optical structure area (20) of an anti-counterfeiting element that responds to ultraviolet light; dissolving the colorless fluorescent material in the liquid material to form a molding material; Selecting a substrate (10) of the UV-responsive anti-counterfeiting element; placing the molding material on the substrate (10); Processing the molded material to form the optical structure area (20) by ultraviolet light curing molding; The covering layer (30) of the ultraviolet light responsive anti-counterfeiting element is processed from the side of the optical structure area (20) away from the substrate (10).

15. The method for preparing an anti-counterfeiting element responsive to ultraviolet light according to claim 14, characterized in that: The covering layer (30) is a covering coating (31), and the process of processing the covering layer (30) of the ultraviolet light responsive anti-counterfeiting element on the side of the optical structure area (20) away from the substrate (10) includes: evaporating the covering coating (31) on the optical structure area (20).

16. The method for preparing an anti-counterfeiting element responsive to ultraviolet light according to claim 14, characterized in that: The covering layer (30) is a covering coating (32), and the process of processing the covering layer (30) of the ultraviolet light responsive anti-counterfeiting element on the side of the optical structure area (20) away from the substrate (10) includes: processing the covering coating (32) on the optical structure area (20) by coating or printing.

17. The method for preparing an anti-counterfeiting element responsive to ultraviolet light according to claim 14, characterized in that: The covering layer (30) is a composite layer (33) formed by a covering plating layer (31) and a covering coating layer (32). The process of processing the covering layer (30) of the UV-responsive anti-counterfeiting element on the side of the optical structure area (20) away from the substrate (10) comprises: Vapor-depositing the covering coating (31) on the optical structure area (20); Removing at least a portion of the covering coating (31) by hollowing out; The covering coating (32) is processed on the optical structure area (20) or the covering coating (31) by coating or printing.

18. The method for preparing an anti-counterfeiting element responsive to ultraviolet light according to claim 14, characterized in that: The ultraviolet light responsive anti-counterfeiting element has a plurality of optical structure areas (20), the plurality of optical structure areas (20) use the same molding material, and the process of arranging the molding material on the substrate (10) includes: printing the molding material on the substrate (10).

19. The method for preparing an anti-counterfeiting element responsive to ultraviolet light according to claim 14, characterized in that: The ultraviolet light responsive anti-counterfeiting element has a plurality of optical structure areas (20), at least two of the plurality of optical structure areas (20) use different colorless fluorescent materials, and the process of arranging the molded material on the substrate (10) includes: arranging the molded material containing different colorless fluorescent materials on the substrate (10) in an intermittent manner by overprinting.

Images