Anti-counterfeiting element, preparation method and anti-counterfeiting product

Abstract

The invention relates to the technical field of optical anti-counterfeiting, and discloses an anti-counterfeiting element, a preparation method and an anti-counterfeiting product.The anti-counterfeiting element comprises a base material, a microstructure forming layer, a transparent protective layer and at least one microstructure, the microstructure forming layer is located on the surface of one side of the base material, and the transparent protective layer is located on the surface of the side, away from the base material, of the microstructure forming layer; the microstructure comprises a first groove, a first isolation layer and at least one magnetic pigment structure, the first groove is formed in the microstructure forming layer, the first isolation layer covers the inner wall of the first groove, a microcavity is defined by the first isolation layer and the transparent protective layer, and the magnetic pigment structure is located in the microcavity; the color of the magnetic pigment structure is the same as that of the first isolating layer. The color of the first isolation layer is the same as that of the magnetic pigment structure, so that the color of the first isolation layer can make up for color loss at the gap, the first microstructure area on the anti-counterfeiting element can display colors, and color loss of partial area of the first microstructure is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of optical anti-counterfeiting, and particularly relates to an anti-counterfeiting element, a preparation method thereof, and an anti-counterfeiting product. Background Art

[0002] In high-security or high-value-added products such as banknotes, stocks, stamps, checks, air tickets, credit cards, passports, etc., anti-counterfeiting elements are generally configured. These anti-counterfeiting elements can ensure the authenticity of information carriers and can also be used to prevent illegal copying.

[0003] In the related art, an anti-counterfeiting element is disclosed. The anti-counterfeiting element has a microcavity, and magnetic pigment flakes are arranged in the microcavity. When an external magnetic field acts on the anti-counterfeiting element, the magnetic pigment flakes in the microcavity will change their positions and angles to produce a specific visual effect. In addition, by adjusting the external magnetic field, the positions and angles of the magnetic pigments can be adjusted, so as to obtain different visual effects.

[0004] However, in the above anti-counterfeiting element, since the magnetic pigment flakes need to move and rotate in the microcavity, there are gaps between the magnetic pigment flakes and the inner wall of the microcavity. Moreover, during the movement and rotation of the magnetic pigment flakes, the size of the gaps will change, and the gaps will cause color loss in the corresponding areas, resulting in a poor visual effect. Summary of the Invention

[0005] In view of this, the present invention provides an anti-counterfeiting element, a preparation method thereof, and an anti-counterfeiting product to solve the problem that there are gaps between the existing magnetic pigment flakes and the inner wall of the microcavity, and during the movement or rotation of the magnetic pigment flakes, the size of the gaps will change, and the gaps will cause color loss in the corresponding areas, resulting in a poor visual effect.

[0006] In a first aspect, the present invention provides an anti-counterfeiting element, including:

[0007] A substrate;

[0008] A micro-structure forming layer located on one surface of the substrate;

[0009] A transparent protective layer located on the surface of the micro-structure forming layer facing away from the substrate;

[0010] At least one micro-structure, which includes a first groove, a first isolation layer, and at least one magnetic pigment structure. The first groove is arranged on the micro-structure forming layer, the first isolation layer covers the inner wall of the first groove, and the first isolation layer and the transparent protective layer enclose a microcavity. The magnetic pigment structure is located in the microcavity, and the magnetic pigment structure has the same color as the first isolation layer.

[0011] Beneficial effects: The color of the first isolation layer is the same as that of the magnetic pigment structure. Therefore, the color of the first isolation layer itself can make up for the lack of color in the gaps. In addition, even if the size of the gaps changes, since the first isolation layer covers the inner wall of the first groove, the color of the first isolation layer itself can still make up for the lack of color in the gaps, enabling a specific color to be displayed in all areas of the first micro-structure region on the anti-counterfeiting element, and avoiding the situation where the visual effect observed deteriorates due to the lack of color in some areas of the first micro-structure. Additionally, when an external magnetic field acts on the anti-counterfeiting element, the magnetic pigment structure in the micro-cavity changes its position and angle under the action of the external magnetic field, so that the observed visual effect changes. Furthermore, a reverse magnetic field can be applied to reset the magnetic pigment structure in the micro-cavity, so that the observed visual effect returns to the initial state. The visual effect of the anti-counterfeiting element provided in this application can be changed by an external magnetic field, increasing the interactive anti-counterfeiting effect and enhancing the anti-counterfeiting ability to meet the requirements of the high-end anti-counterfeiting field. In addition, the change in the visual effect can be observed with the naked eye, which is easy for the public to identify. Additionally, by arranging the magnetic pigment structure in the micro-cavity, the magnetic pigment structure can be protected from the influence of the external temperature and physical friction, thereby avoiding unexpected changes in the visual effect of the magnetic pigment structure, ensuring that the optical anti-counterfeiting element can produce a stable change in the visual effect, and the micro-cavity can also prevent the magnetic pigment structure from falling off and being lost.

[0012] In an alternative embodiment, the micro-structure further includes a fluid medium, and the fluid medium fills the micro-cavity.

[0013] Filling the micro-cavity with a fluid medium can play a lubricating role, reducing the friction between the magnetic pigment structure and the inner wall of the micro-cavity, ensuring that the magnetic pigment structure can move and rotate smoothly. In addition, the fluid can also provide a damping effect, helping to stabilize the movement of the magnetic pigment structure. Additionally, the fluid medium can further protect the magnetic pigment structure, reducing the influence of the external environment on the magnetic pigment structure.

[0014] In an alternative embodiment, the refractive index difference between the fluid medium and the first isolation layer is less than or equal to a first preset value.

[0015] When light passes through media with a large refractive index difference, a large amount of scattering will occur, resulting in the color of the first isolation layer itself interfering with the visual effect expression of the magnetic pigment structure during observation, and further leading to uneven colors observed. By making the refractive index difference between the first isolation layer and the fluid medium less than or equal to the first preset value, the scattering generated when light passes through media with a large refractive index difference is reduced, thereby reducing the interference caused by the color of the first isolation layer itself.

[0016] In an alternative embodiment, the fluid medium is a non-polar material, the transparent protective layer and the micro-structure forming layer are both made of polar materials, and the density of the transparent protective layer is less than that of the fluid medium.

[0017] The intermolecular force is prevalent in non-polar materials, and the intermolecular force is weaker than the binding force of hydrogen bonds and ionic bonds. Therefore, using non-polar materials can reduce the surface tension of the fluid medium, thereby reducing the degree of concave or convex on the surface of the fluid medium, which is beneficial to better filling the microcavity, and thus beneficial to the subsequent preparation of the transparent protective layer. Polar materials and non-polar materials are immiscible, thus avoiding the situation that the transparent protective layer and the micro-structure forming layer are slowly dissolved in the fluid medium. The density of the transparent protective layer is less than that of the fluid medium, ensuring that the transparent protective layer floats on the surface of the fluid medium.

[0018] In an alternative embodiment, it further includes a second isolation layer, the second isolation layer is connected to the first isolation layer, and the second isolation layer is located between the transparent protective layer and the micro-structure forming layer.

[0019] The second isolation layer separates the transparent protective layer from the micro-structure forming layer, avoiding the situation of the protective layer failure caused by the mutual diffusion of the transparent protective layer and the micro-structure, thereby prolonging the service life of the anti-counterfeiting element.

[0020] In an alternative embodiment, the first isolation layer, the second isolation layer, and the magnetic pigment structure are all Fabry-Perot resonator structures, and the second isolation layer has the same color as the magnetic pigment structure.

[0021] The first isolation layer, the second isolation layer, and the magnetic pigment structure are all Fabry-Perot resonator structures, so that the first isolation layer, the second isolation layer, and the magnetic pigment structure will all present different visual effects at different observation angles. The second isolation layer has the same color as the magnetic pigment structure. Therefore, the color of the second isolation layer itself can make up for the color deficiency in the interval area between adjacent two micro-structures, so that the entire anti-counterfeiting element can display a specific color, avoiding the situation that the visual effect observed is deteriorated due to the color deficiency in the interval area.

[0022] In an alternative embodiment, the bottom wall of the first groove is a diffraction grating structure.

[0023] The set visual effect is achieved through the diffraction grating, further enhancing the anti-counterfeiting ability of the anti-counterfeiting element and improving the naked-eye recognition degree of the anti-counterfeiting element. In addition, since the first isolation layer is a Fabry-Perot resonator structure, the diffraction characteristics of the diffraction grating can be enhanced, avoiding the situation that the visual effect generated by the diffraction grating cannot be observed due to the interference of the fluid medium.

[0024] In an alternative embodiment, the length of the magnetic pigment structure is 5um - 50um, the length of the first groove is less than 500um, and the depth of the first groove is less than 100um.

[0025] If the length of the first groove is greater than 500um, the structure of the first groove can be observed with the naked eye, which affects the observation effect. In addition, if the length of the first groove is too large, the fluid medium in the microcavity is likely to be carried out during the process of filling the fluid medium. If the depth of the first groove is greater than 100um, it will cause an increase in the thickness of the anti-counterfeiting element, thereby affecting the production and integration with the anti-counterfeiting product.

[0026] In a second aspect, the present invention provides a method for preparing an anti-counterfeiting element, comprising:

[0027] Providing a substrate;

[0028] Forming a micro-structure forming layer on one side surface of the substrate;

[0029] Forming at least one micro-structure on the micro-structure forming layer;

[0030] The step of forming the micro-structure includes: forming a first groove on the micro-structure forming layer, forming a first isolation layer on the inner wall of the first groove, providing a magnetic pigment structure, and placing the magnetic pigment structure in the first groove;

[0031] Forming a transparent protective layer on the side surface of the micro-structure forming layer facing away from the substrate, and the transparent protective layer and the first isolation layer enclose a microcavity.

[0032] Advantageous effects: The method for preparing the anti-counterfeiting element is simple and easy to implement. In addition, the first isolation layer can make up for the color loss at the gaps, so that the first micro-structure area on the anti-counterfeiting element can all display a specific color, avoiding the situation that the visual effect becomes poor due to the color loss in some areas of the first micro-structure. In addition, the position and angle of the magnetic pigment structure of the anti-counterfeiting element can be reversibly regulated by a magnetic field, so as to obtain a changeable visual effect, which forms a unique advantage for the interaction between the public and the anti-counterfeiting element. In addition, different visual effects can be obtained by regulating the magnetic field, and the observer can perform anti-counterfeiting identification without changing the observation angle, thereby improving the naked-eye recognition degree of the anti-counterfeiting element.

[0033] In a third aspect, the present invention provides an anti-counterfeiting product, comprising the above-mentioned anti-counterfeiting element.

[0034] Advantageous effects: The visual effect of the anti-counterfeiting product can be changed by an external magnetic field, thereby realizing an interactive anti-counterfeiting effect, improving the anti-counterfeiting ability, meeting the requirements of the high-end anti-counterfeiting field, and the anti-counterfeiting product has the advantages of high efficiency, stability and batch production. Description of the Drawings

[0035] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a schematic structural diagram of a substrate, a microstructure formation layer, a first groove, and a diffraction grating structure in the preparation of an anti-counterfeiting element in an embodiment of the present invention;

[0037] Figure 2 It is a schematic structural diagram of a substrate, a microstructure formation layer, a first groove, a diffraction grating structure, a first isolation layer, and a second isolation layer in the preparation of an anti-counterfeiting element in an embodiment of the present invention;

[0038] Figure 3 It is a schematic structural diagram of a substrate, a microstructure formation layer, a first groove, a diffraction grating structure, a first isolation layer, a second isolation layer, a fluid medium, and a magnetic pigment structure in the preparation of an anti-counterfeiting element in an embodiment of the present invention;

[0039] Figure 4 It is a schematic structural diagram of a substrate, a microstructure formation layer, a first groove, a diffraction grating structure, a first isolation layer, a second isolation layer, a fluid medium, a magnetic pigment structure, and a protective layer in the preparation of an anti-counterfeiting element in an embodiment of the present invention;

[0040] Figure 5 It is a schematic structural diagram of the first isolation layer in an embodiment of the present invention;

[0041] Figure 6 It is a schematic structural diagram of the anti-counterfeiting element under the action of a magnetic field in an embodiment of the present invention;

[0042] Figure 7 It is a top view of an anti-counterfeiting product in an embodiment of the present invention;

[0043] Figure 8 It is a top view of the anti-counterfeiting product under the action of a magnetic field in an embodiment of the present invention.

[0044] Explanation of reference numerals:

[0045] 100. Anti-counterfeiting element; 101. Substrate; 102. Microstructure formation layer; 103. Transparent protective layer; 104. Microstructure; 1041. First groove; 1042. Magnetic pigment structure; 1043. Fluid medium; 1044. First isolation layer; 10441. Chromium layer; 10442. Silicon dioxide layer; 10443. Aluminum layer; 105. Second isolation layer; 106. Diffraction grating structure;

[0046] 200. Magnet;

[0047] 300. Carrier. Detailed implementation manner

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only parts related to the present invention rather than all structures are shown in the drawings. In the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concept of the present invention. Various schematic structural diagrams according to embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, and for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are only exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations. Those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs. In the context of the present invention, when a layer / component is referred to as being "on" another layer / component, the layer / component can be directly on the other layer / component, or there can be an intermediate layer / component between them. In addition, if a layer / component is "on" another layer / component in one orientation, then when the orientation is reversed, the layer / component can be "under" the other layer / component.

[0049] In the anti-counterfeiting element in the related art, since the magnetic pigment sheet needs to move and rotate in the microcavity, there is a gap between the magnetic pigment sheet and the inner wall of the microcavity. And during the movement and rotation of the magnetic pigment sheet, the size of the gap will change, and the gap will cause color loss in the corresponding area, resulting in a poor visual effect observed.

[0050] Therefore, the embodiment of the present invention provides an anti-counterfeiting element. The color of the first isolation layer 1044 itself can make up for the color loss at the gap, so that the micro-structure 104 area on the anti-counterfeiting element can all display a specific color, avoiding the situation that the visual effect observed becomes poor due to color loss in some areas of the micro-structure 104.

[0051] An anti-counterfeiting element provided by an embodiment of the present invention, such as Figure 4 and Figure 6As shown, it includes a substrate 101, a microstructure forming layer 102, and at least one microstructure 104. The microstructure forming layer 102 is located on one side surface of the substrate 101, and a transparent protective layer 103 is located on the side surface of the microstructure forming layer 102 facing away from the substrate 101. Each microstructure 104 includes a first groove 1041, a first isolation layer 1044, and at least one magnetic pigment structure 1042. The first groove 1041 is provided on the microstructure forming layer 102, the first isolation layer 1044 covers the inner wall of the first groove 1041, and the first isolation layer 1044 and the transparent protective layer 103 enclose a microcavity. The magnetic pigment structure 1042 is located in the microcavity, and the magnetic pigment structure 1042 has the same color as the first isolation layer 1044.

[0052] Specifically, the substrate 101 serves as the carrier 300 for the microstructure forming layer 102, providing an installation space and bearing the microstructure forming layer 102. The material of the substrate 101 can be polyethylene terephthalate, polyvinyl chloride, paper, and other common anti-counterfeiting substrates 101. The substrate 101 can be opaque, that is, the transmittance of the substrate 101 is less than or equal to 25%. For the anti-counterfeiting element using such a substrate 101, it is necessary to observe from the side of the substrate 101 with the microstructure forming layer 102. Of course, the substrate 101 can also be transparent, that is, the transmittance of the substrate 101 is greater than or equal to 75%. For the anti-counterfeiting element using such a substrate 101, it can be observed from both sides of the substrate 101, that is, the microstructure forming layer 102 can be observed through the substrate 101. The microstructure forming layer 102 serves as the carrier 300 for the microstructure 104 and provides a space for forming the microstructure 104. The microstructure forming layer 102 can be an ultraviolet curable material or other materials. Preferably, the microstructure forming layer 102 is an ultraviolet curable material, and the ultraviolet curable material can be shaped by ultraviolet light irradiation, which is convenient for processing a set structure. The microstructure forming layer 102 can be opaque. For the anti-counterfeiting element using such a microstructure forming layer 102, it is necessary to observe from the side where the microstructure 104 is formed. Since the microstructure forming layer 102 is opaque, the anti-counterfeiting effect of the microstructure 104 cannot be observed from the side of the microstructure forming layer 102 facing the substrate 101. Of course, the microstructure forming layer 102 can also be transparent, and the substrate 101 also needs to be transparent. For the anti-counterfeiting element using such a microstructure forming layer 102, it can be observed from both sides of the anti-counterfeiting element, and the anti-counterfeiting effect of the microstructure 104 can be observed. In this embodiment, the number of the microstructures 104 is not limited and can be one or more. Each microstructure 104 includes a first groove 1041, a first isolation layer 1044, and at least one magnetic pigment structure 1042. The first groove 1041 is formed on the microstructure forming layer 102, and the opening of the first groove 1041 is located on the upper surface of the microstructure forming layer 102. The first groove 1041 is used to accommodate the magnetic pigment structure 1042. Since the magnetic pigment structure 1042 needs to change its position and angle in the first groove 1041, the maximum length of the magnetic pigment structure 1042 is less than the length, width, and depth of the first microcavity. The shapes of the first groove 1041 and the magnetic pigment structure 1042 are not limited in this embodiment, and those skilled in the art can adjust the shapes of the first groove 1041 and the magnetic pigment structure 1042 according to needs. Preferably, in this embodiment, both the first groove 1041 and the magnetic pigment structure 1042 are rectangular parallelepipeds. The first isolation layer 1044 is located in the first groove 1041 and covers the inner wall of the first groove 1041. The first isolation layer 1044 and the transparent protective layer 103 enclose to form a microcavity.In this embodiment, the number of the magnetic pigment structures 1042 is not limited and can be one or more. Each magnetic pigment structure 1042 has a magnetic layer and a non-magnetic layer. The magnetic layer can be a magnetic oxide or a magnetic metal. The magnetic metals include iron, cobalt, nickel, yttrium or other magnetic metals. Of course, the magnetic metals also include alloys added with rare earth elements. The magnetic oxides include iron oxide, chromium oxide, chromite oxide or other magnetic oxides. The non-magnetic layer can be silicon dioxide, magnesium fluoride, titanium dioxide, zinc oxide, aluminum, chromium, copper, organic materials or other non-magnetic materials. The non-magnetic materials or the magnetic materials themselves in the magnetic pigment structure 1042 have specific colors (visual effects), or the magnetic pigment structure 1042 contains pigments to form specific colors, so that the anti-counterfeiting element also has a specific color observable by the naked eye in the initial state. When observing the anti-counterfeiting element or an object containing the optical anti-counterfeiting element, specific colors can be observed, and the colors include hue, brightness and saturation. The transparent protective layer 103 is located on the surface of the microstructure forming layer 102 facing away from the substrate 101. The transparent protective layer 103 covers the first groove 1041, that is, the transparent protective layer 103 closes the opening of the first groove 1041 and encloses a microcavity with the first isolation layer 1044. The microcavity is used to protect the magnetic pigment structure 1042 in the microcavity, prevent the magnetic pigment structure 1042 in the microcavity from being interfered by the external environment, and prevent the magnetic pigment structure 1042 from detaching from the first groove 1041. The transparent protective layer 103 can be an ultraviolet curable material or other materials. Preferably, the transparent protective layer 103 is an ultraviolet curable material, which is convenient for processing a set structure. The light transmittance of the transparent protective layer 103 is greater than or equal to 75%, so that the visual effect of the microstructure 104 can be observed through the transparent protective layer 103.

[0053] For the anti-counterfeiting element provided in this embodiment, the color of the first isolation layer 1044 is the same as that of the magnetic pigment structure 1042. Therefore, the color of the first isolation layer 1044 itself can make up for the color loss at the gap. In addition, even if the size of the gap changes, since the first isolation layer 1044 covers the inner wall of the first groove 1041, the color of the first isolation layer 1044 itself can also make up for the color loss at the gap, so that specific colors can be displayed in the area of the microstructure 104 on the anti-counterfeiting element, avoiding the situation that the visual effect becomes poor due to the color loss in some areas of the microstructure 104. Such as Figure 6As shown, the magnet 200 can provide an external magnetic field. The arcs in the figure are magnetic induction lines, and the direction indicated by the arrow on the arc is the magnetic field direction. When the magnet 200 is arranged below the anti-counterfeiting element, the magnetic induction lines penetrate the anti-counterfeiting element from bottom to top. Under the action of the magnetic field, the magnetic pigment structure 1042 moves along the direction of the magnetic induction lines until the magnetic pigment structure 1042 is parallel to the tangent direction of the magnetic induction lines. The position and angle of the magnetic pigment structure 1042 in the microcavity change under the action of the external magnetic field, so that the visual effect generated by the magnetic pigment structure 1042 changes, that is, any one value or multiple values of the hue, brightness, and saturation shown by the observed magnetic structure change. In addition, a reverse magnetic field can be applied to reset the magnetic pigment structure 1042 in the microcavity, so that the visual effect generated by the magnetic pigment structure 1042 is restored to the initial state. The visual effect of the anti-counterfeiting element provided in this application can be changed by an external magnetic field, increasing the interactive anti-counterfeiting effect and improving the anti-counterfeiting ability to meet the needs of the high-end anti-counterfeiting field. In addition, the change in the visual effect of the magnetic pigment structure 1042 can be observed with the naked eye, which is easy for the public to identify. In addition, by arranging the magnetic pigment structure 1042 in the microcavity, the magnetic pigment structure 1042 can be protected from the influence of external temperature and physical friction, thereby avoiding unexpected changes in the visual effect of the magnetic pigment structure 1042 to ensure that the optical anti-counterfeiting element can produce a stable visual effect change. The microcavity can also prevent the magnetic pigment structure 1042 from falling off and being lost.

[0054] In one embodiment, as Figure 4 and 6As shown, each microstructure 104 further includes a fluid medium 1043. The transmittance of the fluid medium 1043 is greater than or equal to 75%, that is, the fluid medium 1043 is made of a transparent material. Of course, the fluid medium 1043 can also be partially transparent and the rest opaque. The transparent part is used to facilitate the observer to observe the visual effect generated by the magnetic pigment structure 1042. The fluid medium 1043 fills the microcavity, and the magnetic pigment structure 1042 is located within the fluid medium 1043. The thickness of the fluid medium 1043 is less than the depth of the first groove 1041, which is beneficial to form a transparent protective layer 103 on the fluid medium 1043, and during the formation of the transparent protective layer 103, it avoids the overflow of the fluid medium 1043, thus avoiding the waste of the fluid medium 1043. The fluid medium 1043 can be a gas, a liquid, a gel or other deformable materials, so that the magnetic pigment structure 1042 can move and rotate within the fluid medium 1043. The material selection of the fluid medium 1043 does not affect the visual effect and magnetic properties of the magnetic pigment structure 1042. Filling the microcavity with the fluid medium 1043 can play a lubricating role, reducing the friction between the magnetic pigment structure 1042 and the inner wall of the first microcavity to ensure that the magnetic pigment structure 1042 can move and rotate smoothly. In addition, the fluid can also provide a damping effect, which helps to stabilize the movement of the magnetic pigment structure 1042. In addition, the fluid medium 1043 can further protect the magnetic pigment structure 1042, reducing the influence of the external environment on the magnetic pigment structure 1042. The transmittance of the fluid medium 1043 is greater than or equal to 75% to reduce the influence of the color of the fluid medium 1043 itself on the expression of the visual effect of the magnetic pigment structure 1042, so as to ensure that the public can clearly observe the visual effect of the magnetic pigment structure 1042. Since the fluid medium 1043 is located within the microcavity, the microcavity can protect the fluid medium 1043 and the magnetic pigment structure 1042, avoiding the destruction of the microcavity structure or the loss of the fluid medium 1043 due to physical friction or changes in the external temperature and humidity. In addition, a first isolation layer 1044 is located between the fluid medium 1043 and the inner wall of the groove, used to separate the fluid medium 1043 from the inner wall of the first groove 1041 to avoid the erosion of the inner wall of the first groove 1041 by the fluid medium 1043.

[0055] In one embodiment, the difference between the refractive index of the first isolation layer 1044 and the refractive index of the fluid medium 1043 is less than or equal to a first preset value, and the first preset value is 0.2. For example, the material of the fluid medium 1043 is glycerol, and the material of the first isolation layer 1044 is acrylic resin. The refractive index of glycerol is 1.47, and the refractive index of acrylic acid is 1.49. When light passes through media with a large refractive index difference, a large amount of scattering will occur, resulting in the color of the isolation layer itself interfering with the visual effect expression of the magnetic pigment structure 1042 during observation, and further resulting in uneven observed colors. By making the difference between the refractive index of the first isolation layer 1044 and the refractive index of the fluid medium 1043 less than or equal to 0.2, the scattering generated when light passes through media with a large refractive index difference is reduced, thereby reducing the interference caused by the color of the isolation layer itself.

[0056] In one embodiment, the fluid medium 1043 is a non-polar material. For example, the material of the fluid medium 1043 can be carbon tetrachloride or glycerol. Both the transparent protective layer 103 and the microstructure forming layer 102 are made of polar materials. The transparent protective layer 103 and the microstructure forming layer 102 can be made of the same material or different materials. Preferably, in this embodiment, both the transparent protective layer 103 and the microstructure forming layer 102 are made of acrylate, and the density of the transparent protective layer 103 is less than the density of the fluid medium 1043. The intermolecular force is commonly present in non-polar materials, and the intermolecular force is weaker than the binding force of hydrogen bonds and ionic bonds. Therefore, using non-polar materials can reduce the surface tension of the fluid medium 1043, thereby reducing the degree of upward or downward concavity on the surface of the fluid medium 1043, which is beneficial for better filling the microcavity and thus beneficial for the subsequent preparation of the transparent protective layer 103. Polar materials and non-polar materials are immiscible, thus avoiding the situation where the transparent protective layer 103 and the microstructure forming layer 102 slowly dissolve in the fluid medium 1043. The density of the transparent protective layer 103 is less than the density of the fluid medium 1043, ensuring that the transparent protective layer 103 floats on the fluid surface.

[0057] In one embodiment, it further includes a second isolation layer 105, and the second isolation layer 105 is connected to the first isolation layer 1044. The anti-counterfeiting element may separately have the first isolation layer 1044 or the second isolation layer 105, or may have both the first isolation layer 1044 and the second isolation layer 105. Preferably, the anti-counterfeiting element has the first isolation layer 1044 and the second isolation layer 105. The first isolation layer 1044 and the second isolation layer 105 are integrally formed or may be independently formed. The second isolation layer 105 is located between the transparent protective layer 103 and the micro-structure forming layer 102, that is, the second isolation layer 105 covers the surface of the micro-structure forming layer 102 excluding the openings of all the first grooves 1041. Since both the transparent protective layer 103 and the micro-structure forming layer 102 are polar materials, the transparent protective layer 103 and the micro-structure forming layer 102 will diffuse into each other, resulting in the failure of the protective layer. By adding the second isolation layer 105, the transparent protective layer 103 and the micro-structure forming layer 102 are separated, thereby avoiding the mutual diffusion between the transparent protective layer 103 and the micro-structure 104, and further extending the lifespan of the anti-counterfeiting element.

[0058] In one embodiment, the first isolation layer 1044, the second isolation layer 105, and the magnetic pigment structure 1042 are all Fabry - Perot resonator structures, that is, the magnetic pigment structure 1042, the first isolation layer 1044, and the second isolation layer 105 are all composed of metal / dielectric / metal laminates or dielectric / metal / dielectric laminates. Among them, the dielectric may be silicon dioxide or other dielectric materials. Specifically, taking the first isolation layer 1044 as an example, such as Figure 5As shown, the first isolation layer 1044 is composed of a chromium layer 10441 / a silicon dioxide layer 10442 / an aluminum layer 10443 stacked together. The magnetic pigment structure 1042 and the second isolation layer 105 can also be made of the same materials as the first isolation layer 1044. Of course, the magnetic pigment structure 1042 and the second isolation layer 105 can also be made of other metals and dielectrics. Preferably, in this embodiment, the magnetic pigment structure 1042 is made of nickel / silicon dioxide / aluminum / iron / aluminum / silicon dioxide / nickel, where the thickness of nickel is 7nm, the thickness of silicon dioxide is 390nm, the thickness of aluminum is 40nm, and the thickness of iron is 40nm. The nickel / silicon dioxide / aluminum and aluminum / silicon dioxide / nickel symmetrically distributed on both sides both form "Fabry - Perot" structures. The magnetic pigment structure 1042 appears golden yellow when observed from the nickel side. The iron in the middle is the magnetic layer, which can move and rotate under the action of a magnetic field. Moreover, the nickel on both sides can also provide certain magnetism, enhancing the ability of the magnetic pigment structure 1042 to move and rotate, thereby improving the interactive anti - counterfeiting effect of the anti - counterfeiting element. In addition, the magnetic pigment structure 1042 also has a surface relief structure, such as a holographic diffraction structure or a sub - micron scale structure, which can make the magnetic pigment structure 1042 have specific visual effects, increasing the complexity of the visual effects, and thus improving the anti - counterfeiting ability of the anti - counterfeiting element. The second isolation layer has the same color as the magnetic pigment structure 1042. Therefore, the color of the second isolation layer 105 itself can make up for the lack of color in the interval area between two adjacent micro - structures 104, so that the entire anti - counterfeiting element can display a specific color, avoiding the situation where the visual effect becomes poor due to the lack of color in the interval area.

[0059] In one embodiment, the bottom wall of each first groove 1041 is a diffraction grating structure 106. Of course, the bottom walls of some of the first grooves 1041 can be set as the diffraction grating structure 106, or the diffraction grating structure 106 can be not set. The diffraction grating structure 106 is composed of a number of triangular prisms arranged in sequence along the length direction of the first micro - cavity, and the number of triangular pyramids covers the entire bottom wall of the first groove 1041. The height of each triangular prism is 0.3um, and the width of the bottom surface is 2um. Specific visual effects are achieved through the diffraction grating, further enhancing the complexity of the visual effects presented by the anti - counterfeiting element, thereby further enhancing the anti - counterfeiting ability of the anti - counterfeiting element and improving the naked - eye recognizability of the anti - counterfeiting element. In addition, since the first isolation layer 1044 is a Fabry - Perot resonant cavity structure, it can enhance the diffraction characteristics of the diffraction grating and avoid the interference of the fluid medium 1043, so that the visual effects generated by the diffraction grating cannot be observed.

[0060] In one embodiment, the included angle between the inner sidewall of the first groove 1041 and the surface of the microstructure formation layer 102 facing away from the substrate 101 is A, where 90° < A < 180°. That is, the included angle between the inner sidewall of the first groove 1041 and the upper surface of the microstructure formation layer 102 is between 90° and 180°. Obviously, the inner sidewall of the first groove 1041 is inclined, which facilitates the preparation of the first isolation layer 1044 on the inner sidewall of the first groove 1041 and enables the fluid medium 1043 to be smoothly filled into the first groove 1041.

[0061] In one embodiment, the shape of the magnetic pigment structure 1042 and the first groove 1041 is not limited in this embodiment. The shape of the magnetic pigment structure 1042 may be the same as or different from the shape of the first groove 1041. Preferably, in this embodiment, the shape of the first groove 1041 is the same as the shape of the magnetic pigment structure 1042, and this shape is a cuboid. The length of the magnetic pigment structure 1042 is 5 μm - 50 μm. The length and depth of the first groove 1041 are both greater than the maximum length of the magnetic pigment structure 1042. Since the first magnetic pigment only moves and rotates in the length direction and the depth direction, the width of the first groove 1041 may not be greater than the maximum length of the magnetic pigment structure 1042. If movement and deflection in the width direction of the first groove 1041 are required, the width of the first groove 1041 also needs to be greater than the maximum length of the magnetic pigment structure 1042. And the length of the first groove 1041 is less than 500 μm, and the depth of the first groove 1041 is less than 100 μm. If the length of the first groove 1041 is greater than 500 μm, the structure of the first groove 1041 can be observed with the naked eye, which affects the observation effect. In addition, during the process of filling the fluid medium 1043, the fluid medium 1043 in the microcavity is also likely to be carried out. If the depth of the first groove 1041 is greater than 100 μm, it will cause an increase in the thickness of the anti-counterfeiting element, thereby affecting the production and integration with the anti-counterfeiting product.

[0062] In one embodiment, a plurality of microstructures 104 form a microstructure group 104. The plurality of microstructures 104 in the microstructure group 104 are arranged at intervals along a straight line. The anti-counterfeiting element has a plurality of microstructure groups 104. The plurality of microstructure groups 104 are arranged at intervals on the microstructure formation layer 102, and the adjacent two microstructures 104 of different microstructure groups 104 are aligned. The adjacent two microstructures 104 of different microstructure groups 104 may also be arranged in a staggered manner. Of course, the plurality of microstructures 104 may also be randomly arranged to reduce the diffraction situation and avoid interference in the observation chamber.

[0063] In a second aspect, the present invention provides a method for preparing an anti-counterfeiting element, including the following steps:

[0064] S101, Provide a substrate 101. The material of the substrate 101 can be polyethylene terephthalate, polyvinyl chloride, paper, and other common anti-counterfeiting substrates 101. The transmittance of the substrate 101 is less than or equal to 25%.

[0065] S102, Form a micro-structure forming layer 102 on one side surface of the substrate 101.

[0066] Specifically, the micro-structure forming layer 102 can be acrylate or other polar materials. The micro-structure forming layer 102 is initially in a liquid state, and the liquid micro-structure forming layer 102 material is spin-coated on the surface of the substrate 101.

[0067] S103, Form a first groove 1041 on the micro-structure forming layer 102.

[0068] Use a molding process to produce the first groove 1041 on the micro-structure forming layer 102. The molding methods include hot embossing and UV embossing. Preferably, UV embossing is used to produce the first groove 1041. The UV embossing machine adopts automated operation, which can not only meet the requirements of the embossing thickness, achieve the effects of clear and bright embossed pattern lines, high pattern positioning accuracy and reducibility, but also avoid the high temperature of hot embossing during the whole embossing process. Through the UV embossing method, the first groove 1041 can be produced efficiently, stably and in batches.

[0069] Specifically, a master plate with the shape of the first groove 1041 is pressed into the liquid micro-structure forming layer 102, and the liquid micro-structure forming layer 102 is cured and shaped by ultraviolet light irradiation, and then the master plate is peeled off from the cured micro-structure forming layer 102, and the production of the first groove 1041 can be completed.

[0070] S104, As Figure 1 shown, form a diffraction grating structure 106 at the bottom of the first groove 1041;

[0071] The diffraction grating structure 106 can be prepared by mechanical scribing process, holographic ion beam etching process or laminating process.

[0072] S105, As Figure 2 shown, form a first isolation layer 1044 and a second isolation layer 105 by a deposition process. The first isolation layer 1044 encloses to form a second groove.

[0073] The deposition process includes physical vapor deposition and chemical vapor deposition. A chromium layer 10441 / silicon dioxide layer 10442 / aluminum layer 10443 are sequentially formed by the deposition process. Of course, step S105 can also be directly carried out after step S103, and the first isolation layer 1044 or the second isolation layer 105 can also be separately produced in step S104.

[0074] S106, AsFigure 3 As shown, a magnetic pigment structure 1042 is provided, and the magnetic pigment structure 1042 and a fluid medium 1043 are placed into a second groove.

[0075] S105, as shown in the figure, a transparent protective layer 103 is formed on a surface of the second isolation layer 105 facing away from the micro-structure forming layer 102.

[0076] Specifically, the transparent protective layer 103 is made of acrylate. A liquid transparent protective layer 103 is coated on a surface of the second isolation layer 105 facing away from the formed micro-structure 104 through a coating device, and the liquid transparent protective layer 103 is also coated on the fluid medium 1043. Then, the liquid transparent protective layer 103 is cured and shaped by ultraviolet light irradiation. The transparent protective layer 103 and the second groove form a second micro-cavity.

[0077] There are two paths for placing the magnetic pigment structure 1042 inside the second groove. One is to fill the magnetic pigment structure 1042 dispersed in the fluid medium 1043 into the second groove, and then volatilize the fluid medium 1043 by drying. At this time, the fluid medium 1043 in the micro-cavity is air. The other is to fill the magnetic pigment structure 1042 dispersed in the fluid medium 1043 into the second groove and retain the solution. At this time, the micro-cavity is composed of liquid or part liquid and part air.

[0078] The anti-counterfeiting element preparation method provided by this embodiment is simple and easy to implement. In addition, the first isolation layer 1044 can make up for the color loss at the gap, so that specific colors can be displayed in the micro-structure 104 area of the anti-counterfeiting element, avoiding the situation that the visual effect becomes poor due to the color loss in some areas of the micro-structure 104. In addition, the position and angle of the magnetic pigment structure 1042 of the anti-counterfeiting element can be reversibly regulated by a magnetic field, so as to obtain a changeable visual effect, which forms a unique advantage of the interaction between the public and the anti-counterfeiting element. In addition, different visual effects can be obtained by regulating the magnetic field, and the observer can perform anti-counterfeiting identification without changing the viewing angle, thereby improving the naked-eye recognizability of the anti-counterfeiting element.

[0079] In a third aspect, the present invention provides an anti-counterfeiting product, such as Figure 7 shown, including the above-mentioned anti-counterfeiting element 100 and a carrier 300. The carrier 300 can be one of banknotes, stocks, stamps, checks, air tickets, various ticket labels, valuable documents, and various certificates. The anti-counterfeiting element can be transferred to the carrier 300 by pasting, hot stamping or other transfer methods. In the absence of an external magnetic field, the optical anti-counterfeiting element presents the initial visual effect of the magnetic pigment structure 1042.

[0080] Such as Figure 8As shown, for the anti-counterfeiting product provided in this embodiment, when the magnet 200 approaches the anti-counterfeiting product, the visual effect of the optical anti-counterfeiting element changes.

[0081] For the anti-counterfeiting product provided in this embodiment, the optical effect of the anti-counterfeiting product can be changed by an external magnetic field, thereby realizing an interactive anti-counterfeiting effect, improving the anti-counterfeiting ability, meeting the requirements of the high-end anti-counterfeiting field, and the anti-counterfeiting product has the advantages of high efficiency, stability, and batch production.

[0082] In the above description, no detailed description is made of the technical details such as the composition and etching of each layer. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of the required shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not exactly the same as the methods described above. In addition, although the above embodiments are described separately, this does not mean that the measures in each embodiment cannot be used in combination advantageously.

[0083] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. An anti-counterfeiting element, characterized in that, Comprising: a substrate (101); a microstructure forming layer (102) located on one side surface of the substrate (101); a transparent protective layer (103) located on one side surface of the microstructure forming layer (102) facing away from the substrate (101); at least one microstructure (104), which includes a first groove (1041), a first isolation layer (1044) and at least one magnetic pigment structure (1042), the first groove (1041) is provided on the microstructure forming layer (102), the first isolation layer (1044) covers the inner wall of the first groove (1041), and the first isolation layer (1044) and the transparent protective layer (103) enclose a microcavity, the magnetic pigment structure (1042) is located in the microcavity, and the magnetic pigment structure (1042) has the same color as the first isolation layer (1044).

2. The anti-counterfeiting element according to claim 1, characterized in that, The microstructure (104) further includes a fluid medium (1043), and the fluid medium (1043) fills the microcavity.

3. The anti-counterfeiting element according to claim 2, characterized in that, The refractive index difference between the fluid medium (1043) and the first isolation layer (1044) is less than or equal to a first preset value.

4. The security element according to claim 3, characterized in that, The fluid medium (1043) is a non-polar material, both the transparent protective layer (103) and the microstructure forming layer (102) are made of polar materials, and the density of the transparent protective layer (103) is less than the density of the fluid medium (1043).

5. The anti-counterfeiting element according to any one of claims 1-4, characterized in that, It further includes a second isolation layer (105), the second isolation layer (105) is connected to the first isolation layer (1044), and the second isolation layer (105) is located between the transparent protective layer (103) and the microstructure forming layer (102).

6. The security element according to claim 5, characterized in that, The first isolation layer (1044), the second isolation layer (105) and the magnetic pigment structure (1042) are all Fabry - Perot resonator structures, and the second isolation layer (105) has the same color as the magnetic pigment structure (1042).

7. The anti-counterfeiting element according to claim 1 or 6, characterized in that, The bottom wall of the first groove (1041) is a diffraction grating structure (106).

8. The anti-counterfeiting element according to claim 1, characterized in that, The length of the magnetic pigment structure (1042) is 5um - 50um, the length of the first groove (1041) is less than 500um, and the depth of the first groove (1041) is less than 100um.

9. A method for preparing an anti-counterfeiting element, characterized in that, Comprising: providing a substrate (101); forming a microstructure forming layer (102) on one side surface of the substrate (101); forming at least one microstructure (104) on the microstructure forming layer (102); The step of forming the microstructure (104) includes: forming a first groove (1041) on the microstructure forming layer (102), forming a first isolation layer (1044) on the inner wall of the first groove (1041), providing a magnetic pigment structure (1042), and placing the magnetic pigment structure (1042) in the first groove (1041); A transparent protective layer (103) is formed on a surface of the micro-structure forming layer (102) facing away from the substrate (101), and the transparent protective layer (103) and the first isolation layer (1044) enclose to form a micro-cavity.

10. An anti-counterfeiting product, characterized in that, Comprising the anti-counterfeiting element (100) according to any one of claims 1-8.

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