CN111098620A

CN111098620A - Optical anti-counterfeiting element, preparation method of optical anti-counterfeiting element and optical anti-counterfeiting product

Info

Publication number: CN111098620A
Application number: CN201811270781.0A
Authority: CN
Inventors: 王蔚茹; 张昊宇; 李欣毅; 张巍巍; 胡春华
Original assignee: China Banknote Printing and Minting Corp; Zhongchao Special Security Technology Co Ltd
Current assignee: China Banknote Printing and Minting Corp; Zhongchao Special Security Technology Co Ltd
Priority date: 2018-10-29
Filing date: 2018-10-29
Publication date: 2020-05-05

Abstract

The embodiment of the invention provides an optical anti-counterfeiting element, a preparation method of the optical anti-counterfeiting element and an optical anti-counterfeiting product, and belongs to the field of anti-counterfeiting. The optical security element comprises a transparent substrate; the first surface relief structure layer is positioned on at least partial area of one side surface of the substrate; a first plating layer formed on at least a partial region of a surface of the first surface relief structure layer; a second surface relief structure layer formed on at least a partial region of the other side surface of the substrate; and the second plating layer is formed on at least partial area of the surface of the second surface relief structure layer, and the second plating layer and the first plating layer have an overlapping area. Therefore, multi-angle identification of the optical anti-counterfeiting element is realized. At least one of the first plating layer and the second plating layer is an interference light variable plating layer; at least one of the first plating layer and the second plating layer is formed by a precise hollow method.

Description

Optical anti-counterfeiting element, preparation method of optical anti-counterfeiting element and optical anti-counterfeiting product

Technical Field

The invention relates to the field of anti-counterfeiting, in particular to an optical anti-counterfeiting element, a preparation method of the optical anti-counterfeiting element and an optical anti-counterfeiting product.

Background

The optical anti-counterfeiting technology is widely applied to high-end anti-counterfeiting products such as banknotes, cards, passports and the like as an anti-counterfeiting technology which is easy to identify and difficult to forge. With the continuous emergence of new technical and new features in the world, the anti-counterfeiting level requirements of the public on such high-end anti-counterfeiting products are continuously improved, and the optical anti-counterfeiting technology is continuously extended to a multi-anti-counterfeiting feature integration and multi-angle observable visual anti-counterfeiting mode.

Typical optical characteristics such as holographic diffraction, optical dynamic, molar amplification and the like can be formed by the surface relief micro-nano structure, and a metal reflecting layer or a composite coating of metal and metal compounds is evaporated on the surface of the surface relief structure, so that the surface relief micro-nano structure can be used as a reflecting layer to increase the image brightness, and can also be used as an integrated element of anti-counterfeiting characteristics to form a colored coating, an interference light variable coating and the like. The metal reflecting layer or the composite coating is subjected to local patterning hollowing, so that the image-text information of the optical anti-counterfeiting element can be increased, and the image-text information and the optical characteristic image-text information formed by the surface relief structure form dual image-text characteristics under reflection and transmission angles together, so that the anti-counterfeiting identification performance and the anti-counterfeiting performance of the optical anti-counterfeiting element are improved.

Disclosure of Invention

The embodiment of the invention aims to provide an optical anti-counterfeiting element, a preparation method of the optical anti-counterfeiting element and an optical anti-counterfeiting product, which can realize multi-angle identification of the optical anti-counterfeiting element.

In order to achieve the above object, one aspect of the present invention provides an optical security element comprising: a transparent substrate; a first surface relief structure layer located on at least a partial region of the substrate surface; a first plating layer formed on at least a partial region of a surface of the first surface relief structure layer; the second surface relief structure layer is formed on the surface of the first plating layer and covers at least partial area of the substrate; and the second plating layer is formed on at least partial area of the surface of the second surface relief structure layer, and the second plating layer and the first plating layer have an overlapping area.

Another aspect of the invention provides an optical security element comprising: a transparent substrate; a first surface relief structure layer located on at least a partial region of one side surface of the substrate; a first plating layer formed on at least a partial region of a surface of the first surface relief structure layer; a second surface relief structure layer formed on at least a partial region of the other side surface of the substrate opposite to the one side; and the second plating layer is formed on at least partial area of the surface of the second surface relief structure layer, and the second plating layer and the first plating layer have an overlapping area.

In another aspect, the present invention provides a method for preparing an optical security element, the method comprising: forming a first surface relief structure layer on at least a partial region of the substrate surface; forming a first plating layer on at least a partial region of the surface of the first surface relief structure layer; forming a second surface relief structure layer on the surface of the first plating layer, wherein the second surface relief structure layer covers at least partial area of the substrate; and forming a second plating layer on at least partial area of the surface of the second surface relief structure layer, wherein the second plating layer and the first plating layer have an overlapping area.

In another aspect, the present invention provides a method for preparing an optical security element, the method comprising: forming a first surface relief structure layer on at least a partial region of one side surface of the substrate; forming a first plating layer on at least a partial region of the surface of the first surface relief structure layer; forming a second surface relief structure layer on at least a partial region of the other side surface of the substrate opposite to the one side; and forming a second plating layer on at least a partial region of the surface of the second surface relief structure layer; wherein the second plating layer and the first plating layer have an overlapping region.

Optionally, at least one of the first plating layer and the second plating layer is an interference light variable plating layer.

Optionally, the interference light variation plating layer comprises a reflecting layer, a dielectric layer and an absorbing layer.

Optionally, the first plating layer is a single-layer metal reflective plating layer or a high-refractive-index dielectric plating layer, and the second plating layer is the interference light variable plating layer.

Optionally, the optical security element further comprises: a first coating layer formed on a surface of the first plating layer or a surface of the first surface relief structure layer, wherein the first coating layer is opaque, translucent, or transparent, and the first coating layer comprises at least one of: color polymer coating, liquid crystal optically variable coating and OVI optically variable ink.

Optionally, the preparation method further comprises: forming a first coating layer on a surface of the first plating layer or a surface of the first surface relief structure layer, wherein the first coating layer is opaque, translucent, or transparent, and the first coating layer comprises at least one of: color polymer coating, liquid crystal optically variable coating and OVI optically variable ink.

Optionally, at least one of the first surface relief structure layer and the second surface relief structure layer includes at least two kinds of surface relief structures, an aspect ratio of one of the at least two kinds of surface relief structures is larger than an aspect ratio of at least one kind of surface relief structure other than the one kind of surface relief structure, and the plating layer is formed on the at least one kind of surface relief structure.

Optionally, the structure cross-section of the surface relief structure layer comprising the at least two surface relief structures is any one or a combination of: cosine structures, sawtooth structures, square wave structures, cylindrical structures, spherical structures, and pyramid structures.

Optionally, the at least two surface relief structures include a first surface relief structure and a second surface relief structure, an aspect ratio of the first surface relief structure is smaller than an aspect ratio of the second surface relief structure, wherein the first surface relief structure is a holographic diffraction structure or a dynamic blazed grating, and the second surface relief structure is a preset hollow structure.

Optionally, forming a first plating layer on at least a partial region of a surface of the first surface relief structure layer and/or forming the second plating layer on at least a partial region of a surface of the second surface relief structure layer comprises: evaporating a first coating on the first surface relief structure layer; the first coating is not added with a coating or coated with a dealumination protective layer with the dry coating weight smaller than a first preset value, wherein the first preset value is related to the depth-to-width ratio of the surface relief structure of a preset coating hollowed-out area in the first surface relief structure layer; evaporating the second plating layer on the second surface relief structure layer; and hollowing out the optical anti-counterfeiting element by at least one of: the device comprises an alkali washing hollow-out layer, a water washing hollow-out layer and an acid washing hollow-out layer, wherein the first plating layer is a single-layer metal reflection plating layer, and the second plating layer is an interference light variable plating layer.

Optionally, forming a first plating layer on at least a partial region of a surface of the first surface relief structure layer and/or forming the second plating layer on at least a partial region of a surface of the second surface relief structure layer comprises: positioning overprinting ink or a coating on an area, which does not need to form a plating layer, of the surface relief structure layer; evaporating and plating a plating layer on the surface relief structure layer; and placing the optical anti-counterfeiting element in a solution to clean the ink or the coating layer, so that the coating layer is reserved only in the area where the coating layer is preset in the surface relief structure layer, wherein the surface relief structure layer comprises the first surface relief structure layer and/or the second surface relief structure layer.

Optionally, forming the first plating layer on at least a partial region of the surface of the first surface relief structure layer and/or forming the second plating layer on at least a partial region of the surface of the second surface relief structure layer comprises: completing the evaporation plating on the surface of the surface relief structure layer; positioning overprinting a plating layer protective ink or coating on an area of the surface relief structure layer where the plating layer is required to be reserved; placing the optical anti-counterfeiting element in an acidic or alkaline solution to clean the plating layer protective ink or the coating so that the plating layer is reserved on the surface of the surface relief structure layer, wherein the area of the plating layer is preset to be reserved; wherein the surface relief structure layer comprises the first surface relief structure layer and/or the second surface relief structure layer.

In a further aspect, the invention provides an optical anti-counterfeiting product, which comprises the optical anti-counterfeiting element.

Through the technical scheme, the first plating layer and the second plating layer are respectively formed on the surfaces of the two surface relief structure layers, and the first plating layer and the second plating layer have overlapping areas, so that different image-text characteristics can be observed when the optical anti-counterfeiting element is observed from the front side and the back side. When the first coating layer is facing the viewer, parts of the second coating layer are masked and vice versa. Therefore, the multi-angle identification of the optical anti-counterfeiting element is realized, the optical anti-counterfeiting element can present multiple visual appearances, and the anti-counterfeiting performance of the optical anti-counterfeiting element is improved.

Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention without limiting the embodiments of the invention. In the drawings:

fig. 1 is a schematic structural diagram of an optical security element according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an optical security element according to another embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of an optical security element according to another embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of an optical security element according to another embodiment of the present invention;

FIG. 5 is a top view of the optical security element of FIG. 3;

FIG. 6 is a flow chart of a method for producing an optical security element according to another embodiment of the present invention;

FIG. 7 is a flow chart of a method for making an optical security element according to another embodiment of the present invention; and

fig. 8 is a schematic process diagram of manufacturing the optical security element shown in fig. 3.

Description of the reference numerals

1 substrate 2 first surface relief Structure layer

3 first coating 4 second surface relief structure layer

5 second plating layer 6 Single Metal reflective plating layer

7 interference light variable coating 8 protective layer

9 hot melt adhesive layer 10 metal reflecting aluminum layer

11 first feature of dealumination protective layer 12

13 second feature

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.

One aspect of the embodiments of the present invention is to provide an optical anti-counterfeiting element for protecting valuable articles or valuable documents, which can be identified from multiple angles by using a multi-color plating layer, a multi-surface relief micro-nano structure and a local precise or positioning hollow manner, so as to further improve the anti-counterfeiting performance of the optical anti-counterfeiting element, and a preparation method for forming the optical anti-counterfeiting element. In the embodiment of the invention, in order to meet the requirement of high-end anti-counterfeiting products on multi-angle identification optical anti-counterfeiting elements, the visual effect is optimized and the anti-counterfeiting performance is improved, and various surface relief micro-nano structures, single and interference light variable metal coatings, and hollow and precise hollow features are integrated to form new optical anti-counterfeiting elements and features.

In addition, the optical anti-counterfeiting element provided by the embodiment of the invention can be used for anti-counterfeiting optical anti-counterfeiting elements of valuable documents or valuable articles. The value document or value item may for example comprise a merchandise identification, a value document, a banknote, a credit card, an identification card or a passport or the like.

In addition, the optical anti-counterfeiting element provided by the embodiment of the invention can also be used as anti-counterfeiting safety lines, anti-counterfeiting wide strips, anti-counterfeiting adhesive films, anti-counterfeiting labels and other high-end anti-counterfeiting products to be applied to anti-counterfeiting of RMB and other related high-end safety products, and is particularly suitable for transparent windows or other product forms capable of being observed at multiple angles.

Fig. 1 is a schematic structural diagram of an optical security element according to an embodiment of the present invention. As shown in fig. 1, the optical security element includes a substrate 1, a first surface relief structure layer 2, a first plating layer 3, a second surface relief structure layer 4, and a second plating layer 5. The substrate 1 is a transparent substrate, the first surface relief structure layer 2 is located in at least a partial region of the substrate 1, the first plating layer 3 is formed on at least a partial region of the first surface relief structure layer 2, the second surface relief structure layer 4 is formed on the surface of the first plating layer 3 and covers at least a partial region of the substrate 1, the second plating layer 5 is formed on at least a partial region of the second surface relief structure layer 4, and an overlapping region exists between the second plating layer 5 and the first plating layer 3. In addition, the formation of the second surface relief structure layer 4 on the surface of the first plating layer 3 is not limited to the formation of the second surface relief structure layer 4 on the first plating layer 3, that is, the second surface relief structure layer 4 may cover only at least a partial region of the first plating layer 3, or may cover a region larger than the first plating layer 3. In addition, in the embodiment of the present invention, the arrangement and position of the plating layer and the surface relief structure layer may be determined according to the requirement of the visual effect, for example, compared with the substrate 1, the first surface relief structure layer 2 and the second surface relief structure layer may be arranged on different sides, besides the same side, to present different visual effects. In addition, in the embodiment of the present invention, the second surface relief structure layer 4 and the first surface relief structure layer 2 may be completely overlapped, that is, the covered area of the substrate 1 is completely the same.

And forming a first plating layer and a second plating layer on the surfaces of the two surface relief structure layers respectively, wherein the first plating layer and the second plating layer have an overlapping area, so that different image-text characteristics can be observed when the optical anti-counterfeiting element is observed from the front side and the back side. When the first coating layer is facing the viewer, parts of the second coating layer are masked and vice versa. Therefore, the multi-angle identification of the optical anti-counterfeiting element is realized, the optical anti-counterfeiting element can present multiple visual appearances, and the anti-counterfeiting performance of the optical anti-counterfeiting element is improved. In addition, if the two surface relief structure layers are at least partially different, the characteristics of the optical anti-counterfeiting element when being observed can be increased, the anti-counterfeiting identification performance of the optical anti-counterfeiting element is further increased, and the anti-counterfeiting performance of the optical anti-counterfeiting element is improved. In addition, if the first plating layer and/or the second plating layer are local plating layers, the shape structure of the first plating layer and/or the second plating layer is observed when the optical anti-counterfeiting element is observed in a transmission mode, and the image-text information of the optical anti-counterfeiting element is increased; under the condition that the first plating layer and the second plating layer are local plating layers, an overlapping area exists, so that different structural shapes can be observed by performing transmission observation on the front side and the back side of the optical anti-counterfeiting element during transmission observation, the anti-counterfeiting identification performance of the optical anti-counterfeiting element is further improved, and the anti-counterfeiting performance of the optical anti-counterfeiting element is improved.

Fig. 2 is a schematic structural diagram of an optical security element according to another embodiment of the present invention. The optical security element shown in fig. 2 differs from the optical security element shown in fig. 1 in that the first surface relief structure layer 2 is located on at least a partial region of one side of the substrate 1, the first plating layer 3 is formed on at least a partial region of the first surface relief structure layer 2, the second surface relief structure layer 4 is formed on at least a partial region of the other side of the substrate 1, and the second plating layer 5 is formed on at least a partial region of the second surface relief structure layer 4.

Optionally, in an embodiment of the present invention, at least one of the first plating layer and the second plating layer is an interference light variable plating layer. The interference light variable coating can make the optical anti-counterfeiting element show optical characteristics of color change when being observed. Therefore, when the front side and the back side of the optical anti-counterfeiting element are subjected to reflection observation, the front side and the back side show different color characteristics, and at least one of the front side and the back side is a special optically variable color, so that the anti-counterfeiting identification performance of the optical anti-counterfeiting element is further improved, and the anti-counterfeiting performance of the optical anti-counterfeiting element is improved. Optionally, in an embodiment of the present invention, the interference light variation plating layer includes a reflective layer, a dielectric layer, and an absorption layer. Wherein the reflective layer or the absorbing layer is adjacent to the surface relief structure layer. The reflecting layer comprises metals such as aluminum, silver, copper and the like or alloys thereof, the dielectric layer comprises metal fluorides such as magnesium fluoride, silicon oxide, zinc sulfide, titanium nitride and the like, metal oxides, metal sulfides and metal nitrides, and the absorbing layer comprises metals such as chromium, nickel and the like or alloys thereof.

Optionally, in an embodiment of the present invention, the first plating layer and/or the second plating layer is a single metal reflective plating layer or a high refractive index dielectric layer plating layer. The single-layer metal reflective coating can comprise metals such as aluminum, silver, copper and the like or alloys thereof; the high refractive index dielectric layer coating may include a dielectric layer material having a refractive index greater than 1.7, for example, the dielectric layer material may include metal fluorides such as magnesium fluoride, silicon oxide, zinc sulfide, titanium nitride, metal oxides, metal sulfides, metal nitrides, and the like. Furthermore, the first plating layer and/or the second plating layer may be a partial plating layer.

Optionally, in an embodiment of the present invention, the first plating layer is a single-layer metal reflective plating layer or a high refractive index dielectric layer plating layer, and the second plating layer is an interference light variable plating layer. The single-layer metal reflective coating can comprise metals such as aluminum, silver, copper and the like or alloys thereof; the high refractive index dielectric layer coating may include a dielectric layer material having a refractive index greater than 1.7, for example, the dielectric layer material may include metal fluorides such as magnesium fluoride, silicon oxide, zinc sulfide, titanium nitride, metal oxides, metal sulfides, metal nitrides, and the like. Furthermore, the first plating layer and/or the second plating layer may be a partial plating layer.

Optionally, in an embodiment of the present invention, the optical security element further includes: the first coating is formed on the surface of the first plating layer or the surface of the first surface relief structure layer; and/or a second coating formed on the surface of the second plating layer or the surface of the second surface relief structure layer, wherein the first coating and/or the second coating are opaque, translucent or transparent, and the first coating and/or the second coating comprise at least one of the following: color polymer coating, liquid crystal optically variable coating and OVI optically variable ink.

Optionally, in an embodiment of the present invention, at least one of the first surface relief structure layer and the second surface relief structure layer includes at least two kinds of surface relief structures, an aspect ratio of one of the at least two kinds of surface relief structures is greater than an aspect ratio of at least one kind of surface relief structure other than the one kind of surface relief structure, and the plating layer is formed on the at least one kind of surface relief structure. For example, in the first surface relief structure layer and the second surface relief structure layer, the first surface relief structure layer includes at least two kinds of surface relief structures, one of the surface relief structures has the largest aspect ratio, and the first plating layer is formed on at least one kind of surface relief structure other than the surface relief structure having the largest aspect ratio. Similarly, for the second surface relief structure layer, the same situation as the first surface relief structure layer in this example may exist, and the second plating layer is formed on at least one surface relief structure other than the surface relief structure having the largest aspect ratio in the second surface relief structure layer. The plating layer is formed on other undulating structures except the undulating structure with the largest aspect ratio to form a local plating layer, and in the process of preparing the optical anti-counterfeiting element, the undulating structures with different aspect ratios are beneficial to realizing precise hollowing of the local plating layer. The shape of the local plating layer can be designed according to the patterns displayed according to actual needs, and when the optical anti-counterfeiting element is observed in a transmission mode, the shape of the local plating layer can be observed, so that the image-text information of the optical anti-counterfeiting element can be increased, the anti-counterfeiting identification performance of the optical anti-counterfeiting element is further improved, and the anti-counterfeiting performance of the optical anti-counterfeiting element is further improved. In addition, the color and shape difference of the two local coatings respectively formed on the surfaces of the two surface relief structure layers further increases the image-text characteristics of the optical anti-counterfeiting element when the optical anti-counterfeiting element is observed at multiple angles, increases the anti-counterfeiting identification performance of the optical anti-counterfeiting element, and improves the anti-counterfeiting performance of the optical anti-counterfeiting element.

In addition, in the embodiment of the present invention, the at least two surface relief structures respectively included in the first surface relief structure layer and the second surface relief structure layer may be the same, may also be different, or at least partially different, which is not limited thereto. If the first surface relief structure layer and the second surface relief structure layer respectively comprise at least two surface relief structures which are at least partially different, the optical anti-counterfeiting element can be observed from the front side and the back side to show different optical appearances, so that the anti-counterfeiting identification performance of the optical anti-counterfeiting element is improved, and the anti-counterfeiting performance of the optical anti-counterfeiting element is further improved.

Optionally, in an embodiment of the present invention, the structural cross section of the surface relief structure layer including at least two kinds of surface relief structures is any one of or a combination of: cosine structures, sawtooth structures, square wave structures, cylindrical structures, spherical structures, pyramid structures, and the like.

Optionally, in an embodiment of the present invention, the at least two surface relief structures include a first surface relief structure and a second surface relief structure, an aspect ratio of the first surface relief structure is smaller than an aspect ratio of the second surface relief structure, where the first surface relief structure is an effective optical structure such as a holographic diffraction structure or a dynamic blazed grating, and the second surface relief structure is a preset hollow structure. The preset hollow structure is not limited as long as the depth-to-width ratio of the first surface relief structure is smaller than that of the second surface relief structure. For example, the first surface relief structure layer comprises a holographic diffraction structure and a first preset hollow structure, wherein the depth-to-width ratio of the holographic diffraction structure is smaller than that of the first preset hollow structure; the second surface relief structure layer comprises dynamic blazed gratings and a second preset hollow structure, wherein the depth-to-width ratio of the dynamic blazed gratings is smaller than that of the second preset hollow structure, and the first preset hollow structure in the first surface relief structure layer and the second preset hollow structure in the second surface relief structure layer can be the same hollow structure or different hollow structures. For another example, in the first surface relief structure layer and the second surface relief structure layer, the first relief structure is a holographic diffraction structure or a dynamic blazed grating, and the second relief structure is a hollow structure with an aspect ratio larger than a first preset value.

Optionally, an embodiment of the present invention provides an optical security element, which includes at least two surface relief structure layers and a local plating layer, where each surface relief structure layer has a local plating layer formed thereon. In addition, at least one of the local coatings formed on the two surface relief structure layers is an interference light variable coating. The local plating layer is realized by vacuum coating and subsequent local plating layer hollowing process, and at least part of the local plating layer is realized by an accurate hollowing mode of accurate alignment of an effective optical structure and hollowing. The precise hollowing is a special plating layer hollowing mode which is controllable by an optical structure and is formed after the processes of optical structure copying, vacuum coating and hollowing. The precise hollow has the characteristics of high-precision positioning of visual optical microstructure characteristics and hollow characteristics and high precision of hollow patterns. The local hollow plating layer formed by the accurate hollow mode can be a single-layer metal reflection plating layer or a multi-layer interference light variable plating layer.

In addition, in the two-surface relief structure layer, various surface relief micro-nano optical structures can be included, for example, a holographic diffraction structure, a dynamic blazed grating and the like are included. And at least one of the two surface relief structure layers comprises two or more surface relief structures with different shapes and sizes. For example, one of the two surface relief structure layers comprises a holographic diffraction structure and a hollow structure with a high depth-to-width ratio; or the other surface relief structure layer of the two surface relief structure layers comprises dynamic blazed gratings and a hollow structure with a high depth-to-width ratio; or the two surface relief structure layers exist simultaneously, namely, the two surface relief structure layers both comprise a holographic diffraction structure and a high depth-to-width ratio hollow structure or both comprise dynamic blazed gratings and a high depth-to-width ratio hollow structure. Optionally, the aspect ratio of the high aspect ratio hollowed-out structure is greater than that of the holographic diffraction structure or greater than that of the dynamic blazed grating, so that precise hollowing can be realized. In addition, the relief structures of the surface relief structures in the two surface relief structure layers are at least partially different, so that when the optical anti-counterfeiting element is observed at different angles, multiple visual appearances are presented, and the anti-counterfeiting performance of the optical anti-counterfeiting element is improved.

In addition, the arrangement mode and the position of the substrate, the two surface relief structure layers and the local plating layer can be determined according to the requirement of visual effect. Optionally, the two surface relief structure layers are located on the same side or two sides of the substrate, and the surface of the two surface relief structure layers is provided with a local plating layer, wherein at least one of the two surface relief structure layers is an interference light variable plating layer. In addition, the substrate may comprise a transparent polymer film.

In addition, the optical anti-counterfeiting element provided by the embodiment of the invention can be arranged on valuable articles or valuable papers in an anti-counterfeiting safety line, an anti-counterfeiting window wide strip, an anti-counterfeiting transfer wide strip or an anti-counterfeiting label mode, and is especially arranged on paper money or plastic money with a transparent or semitransparent window in an anti-counterfeiting window wide strip or anti-counterfeiting label mode, so that the optical anti-counterfeiting element is used for multi-angle multi-recognition of front and back reflection and transmission of the window part.

Optionally, in an embodiment of the present invention, the optical security element may further include a release layer disposed between the substrate and the surface relief structure layer, making the optical security element suitable for use in a transfer-type optical security product.

Optionally, in an embodiment of the present invention, the optical security element may further include a first protective layer and a second protective layer, where the first protective layer is formed on the first plated layer and the second protective layer is formed on the second plated layer. In addition, the shape of the protective layer may coincide with the shape and position of the plating layer or form a full-thickness coating. Optionally, the protective layer may include one or more of a transparent polymer coating, a color coating (the color coating may be opaque, translucent or transparent), a liquid crystal optically variable coating, an OVI optically variable ink, and the like.

Optionally, in an embodiment of the present invention, the optical anti-counterfeiting element further includes a hot melt adhesive layer, the hot melt adhesive layer is located at an outermost side of the optical anti-counterfeiting element and is located on a side of the optical anti-counterfeiting element, which needs to be in contact with other products, and the hot melt adhesive layer is used for attaching the optical anti-counterfeiting element to the other products, for example, attaching the optical anti-counterfeiting element to anti-counterfeiting paper, a film, and the like.

Optionally, in the embodiment of the present invention, the substrate may have a substrate film with a higher optical transmittance, which is suitable for the thickness and machining strength of the whole security element, and the surface is flat and easy to be coated and printed. Specifically, the base film material used in the embodiment of the present invention may be all film materials satisfying the above conditions, such as one or a blend or a copolymer of polyethylene, biaxially oriented polypropylene, nylon, polyamide, polycarbonate, polyester (polyethylene terephthalate, polybutylene terephthalate, and the like), polyurethane, polymethyl methacrylate, triethylcellulose, unsaturated polyester resin, epoxy resin, and the like. Optionally, the substrate film has a thickness of 6 to 30 microns, preferably 8 to 20 microns.

Optionally, in the embodiment of the present invention, the optical anti-counterfeiting element may be disposed on the valuable paper or valuable article in the form of an anti-counterfeiting product such as a security thread, a window sticker, a transfer wide strip, or a label, so as to improve anti-counterfeiting performance. When the optical anti-counterfeiting element provided by the embodiment of the invention is arranged on valuable documents or valuable articles in the form of a safety line, the width of the optical anti-counterfeiting element is 2 mm to 10 mm, preferably 3 mm to 8 mm; the optical security element has a thickness of 10 to 50 microns, preferably 25 to 40 microns. When the optical anti-counterfeiting element is arranged on the valuable paper or valuable goods in the form of a window sticker, the width of the optical anti-counterfeiting element is 8 mm to 30 mm, preferably, the width is 10 mm to 20 mm; the optical security element has a thickness of 10 to 50 microns, preferably a thickness of 20 to 40 microns. When the optical security element is arranged on a value document or value product in the form of a transfer wide strip or label, the width of the optical security element is 5 mm to 30 mm, preferably 8 mm to 20 mm; the optical security element has a thickness of 10 to 50 microns, preferably a thickness of 20 to 40 microns.

Fig. 3 is a schematic cross-sectional structure diagram of an optical security element according to another embodiment of the present invention. As shown in fig. 3, in this embodiment, the first surface relief structure layer 2 and the second surface relief structure layer 4 are respectively located on both sides of the substrate 1. Alternatively, the substrate 1 is a polymer film. The first surface relief structure layer 2 is located below the substrate 1, the first surface relief structure layer 2 includes a holographic diffraction structure and a first high aspect ratio hollow structure, and a local single-layer metal reflective coating 4, such as an aluminum coating, is formed on the surface of the holographic diffraction structure. The depth-to-width ratio of the first height-to-width ratio hollow structure is larger than that of the holographic diffraction structure. The local single-layer metal reflective coating 4 is adjacent to the first surface relief structure layer 2 and accurately corresponds to the holographic diffraction structure area a1, the area a1 is an image area, and the hollow structure area b1 realizes the precise hollow of the metal coating. The second surface relief structure layer 4 is positioned above the substrate 1, the second surface relief structure layer 4 comprises dynamic blazed gratings and a second high aspect ratio hollow structure, and a local interference light variable coating 7 is formed on the surfaces of the dynamic blazed gratings. And the depth-to-width ratio of the second high depth-to-width ratio hollow structure is greater than that of the dynamic blazed grating. The structure of the interference light variation plating layer 7 may be a multilayer structure of a reflective layer, a dielectric layer, and an absorption layer in this order, for example, the interference light variation plating layer 7 includes aluminum, silicon dioxide, and chromium. The local interference light variable coating 7 is adjacent to the second surface relief structure layer 4 and accurately corresponds to the dynamic blazed grating area a2, and the hollow-out structure area b2 completes local accurate hollow-out and has no coating structure. In addition, functional coatings, such as a protective layer 8 or a hot melt adhesive layer 9, can be added to the optical security element at the lowermost and uppermost positions, depending on the product application requirements of the optical security element. Wherein, the functional coating can be a single coating structure or a multi-coating structure. The functional coating is respectively adjacent to the surface relief structure layer and the local single-layer metal reflection coating or the interference light variation coating to form a complete product structure. As shown in fig. 3, a protective layer 8 is formed on the region b1 of the first surface relief structure layer and the surface of the single-layer metal reflective plating layer 6, and a hot melt adhesive layer 9 is formed on the region b2 of the second surface relief structure layer and the surface of the interference light variable plating layer 7.

Fig. 4 is a schematic cross-sectional structure view of an optical security element according to another embodiment of the present invention. As shown in fig. 4, the first surface relief structure layer 2 and the second surface relief structure layer 3 are located on the same side of the substrate 1, wherein the substrate 1 is a polymer film. The first surface relief structure layer 2 is located above the substrate 1, and the first surface relief structure layer 2 includes a holographic diffraction structure and a first aspect ratio hollow structure, wherein the aspect ratio of the first aspect ratio hollow structure is greater than that of the holographic diffraction structure. And forming a local single-layer metal reflection coating 6 on the surface of the holographic diffraction structure, and forming accurate hollowing accurately corresponding to the holographic diffraction structure area a 1. The second surface relief structure layer 4 is located above the first surface relief structure layer 2 and the local single-layer metal reflective coating 6, and the second surface relief structure layer 4 comprises dynamic blazed gratings and a second high aspect ratio hollow structure, wherein the aspect ratio of the second high aspect ratio hollow structure is greater than that of the dynamic blazed gratings. And a local interference light variable coating 7 is formed on the surface of the dynamic blazed grating. The structure of the interference light variation plating layer 7 may be a multilayer structure of a reflective layer, a dielectric layer, and an absorption layer in this order, for example, the interference light variation plating layer 7 includes aluminum, silicon dioxide, and chromium. The local interference light variable coating 7 is adjacent to the second surface relief structure 4 and accurately corresponds to the dynamic blazed grating area a2, and the hollow-out structure area b2 is locally and accurately hollow out. Optionally, a stripping coating which can be hot stamped and stripped is arranged between the first surface relief structure layer 2 and the base material 1, and the two surface relief structure layers are arranged below the base material and the stripping coating, so that an application mode of the optical anti-counterfeiting element in hot stamping wide strips and hot stamping labels is realized. The stripping coating can be used in transfer type optical anti-counterfeiting products.

In the embodiment of the invention, the optical anti-counterfeiting element is provided with the first surface relief structure layer and the second surface relief structure layer, and the surfaces of the two relief structure layers are respectively provided with the local single-layer metal reflective coating and the interference light variable coating, so that the optical anti-counterfeiting element can have multi-angle and multi-appearance anti-counterfeiting characteristics. For example, the optical anti-counterfeiting element adopts a multilayer structure shown in fig. 3, the second surface relief structure layer 4 above the substrate 1 is provided with an interference light variable coating 7 with a local precise hollow, the first surface relief structure layer 2 below the substrate 1 is provided with a single-layer metal reflective coating 6 with a local precise hollow, and the synchronous replication of the two surface relief structure layers is realized by adopting double-sided positioning registration, so that the positioning precision of the two local coatings is ensured, and the front and back two-sided reflective appearance characteristics shown in fig. 5 can be realized. Fig. 5 is a top view of the optical security element shown in fig. 3. The optically variable holographic hollowed-out integrated feature shown in fig. 5A is visible from the top of the optical anti-counterfeiting element in a plan view (a first feature 12 and a second feature 13 are integrated, wherein the first feature 12 is a feature presented by a dynamic diffraction grating, and the second feature 13 is a feature presented by a holographic diffraction structure), while the single holographic hollowed-out feature shown in fig. 5B is visible from the bottom of the optical anti-counterfeiting element, and the appearance profile feature shown in fig. 5B is visible from a perspective view.

In another aspect, the present invention provides a method for manufacturing an optical anti-counterfeiting element. Fig. 6 is a flowchart of a method for manufacturing an optical security element according to another embodiment of the present invention. As shown in fig. 6, the method includes the following steps.

In step S60, a first surface relief structure layer is formed on at least a partial region of the substrate. In step S61, a first plating layer is formed on at least a partial region of the first surface relief structure layer. In step S62, a second surface relief structure layer is formed on the surface of the first plating layer, wherein the second surface relief structure layer covers at least a partial region of the substrate. In step S63, a second plating layer is formed on at least a partial region of the second surface relief structure layer. Wherein the second plating layer and the first plating layer have an overlapping region.

And forming a first plating layer and a second plating layer on the surfaces of the two surface relief structure layers respectively, wherein the first plating layer and the second plating layer have an overlapping area, so that different image-text characteristics can be observed when the optical anti-counterfeiting element is observed from the front side and the back side. When the first coating layer is facing the viewer, parts of the second coating layer are masked and vice versa. Therefore, the multi-angle identification of the optical anti-counterfeiting element is realized, the optical anti-counterfeiting element can present multiple visual appearances, and the anti-counterfeiting performance of the optical anti-counterfeiting element is improved.

Fig. 7 is a flowchart of a method for manufacturing an optical security element according to another embodiment of the present invention. As shown in fig. 7, the preparation method includes the following steps. In step S70, a first surface relief structure layer and a second surface relief structure layer are simultaneously formed on at least partial areas of both sides of the substrate, that is, the first surface relief structure layer is formed on at least partial area of one side surface of the substrate, and the second surface relief structure layer is formed on at least partial area of the other side surface of the substrate opposite to the one side. In step S71, a first plating layer is formed on at least a partial region of the first surface relief structure layer. In step S72, a second plating layer is formed on at least a partial region of the surface of the second surface relief structure layer. Wherein the second plating layer and the first plating layer have an overlapping region. It should be noted that the order of forming the first plating layer and the second plating layer is not fixed, and the first plating layer may be formed on at least a partial region of the first surface relief structure layer, and then the second plating layer may be formed on at least a partial region of the second surface relief structure layer, or the second plating layer may be formed on at least a partial region of the second surface relief structure layer, and then the first plating layer may be formed on at least a partial region of the first surface relief structure layer, which is not intended to limit the present invention. Optionally, in the embodiment of the present invention, after the first plating layer and the second plating layer can respectively complete the vacuum plating layer, the hollowing is synchronously implemented.

Optionally, in an embodiment of the present invention, at least one of the first plating layer and the second plating layer is an interference light variable plating layer.

Optionally, in an embodiment of the present invention, the interference light variation plating layer includes a reflective layer, a dielectric layer, and an absorption layer.

Optionally, in an embodiment of the present invention, the first plating layer is a single-layer metal reflective plating layer or a high refractive index dielectric plating layer, and the second plating layer is the interference light variable plating layer.

Optionally, in an embodiment of the present invention, the preparation method further includes: forming a first coating on the surface of the first plating layer or the surface of the first surface relief structure layer; and/or forming a second coating on the surface of the second plating layer or the surface of the second surface relief structure layer, wherein the first coating and/or the second coating are opaque, translucent or transparent, and the first coating and/or the second coating comprise at least one of the following: color polymer coating, liquid crystal optically variable coating and OVI optically variable ink.

Optionally, in an embodiment of the present invention, at least one of the first surface relief structure layer and the second surface relief structure layer includes at least two kinds of surface relief structures, an aspect ratio of one of the at least two kinds of surface relief structures is larger than an aspect ratio of at least one kind of surface relief structure other than the one kind of surface relief structure, and the plating layer is formed on the at least one kind of surface relief structure.

Optionally, in an embodiment of the present invention, the structural cross section of the surface relief structure layer including at least two kinds of surface relief structures is any one of or a combination of: cosine structures, sawtooth structures, square wave structures, cylindrical structures, spherical structures, and pyramid structures.

Optionally, in an embodiment of the present invention, the at least two surface relief structures include a first surface relief structure and a second surface relief structure, an aspect ratio of the first surface relief structure is smaller than an aspect ratio of the second surface relief structure, where the first surface relief structure is an effective optical structure such as a holographic diffraction structure or a dynamic blazed grating, and the second surface relief structure is a preset hollow structure.

Optionally, in an embodiment of the present invention, forming a first plating layer on at least a partial region of a surface of the first surface relief structure layer and/or forming a second plating layer on at least a partial region of a surface of the second surface relief structure layer, and forming a precise hollow, and implementing the hollow of the plating layer by using a precise hollow process specifically includes: evaporating a first coating on the first surface relief structure layer; the first coating is not added with a coating or is coated with a dealuminizing protective layer with the dry coating weight smaller than a first preset value, wherein the first preset value is related to the depth-to-width ratio of the surface relief structure of the hollow area of the preset coating in the first surface relief structure layer; evaporating the second plating layer on the second surface relief structure layer; and hollowing out the optical security element by at least one of: and performing alkali washing, water washing and acid washing to form an accurate hollowed-out local coating with an effective optical microstructure aligned with the hollowed-out area without error, wherein the first coating is a single-layer metal reflection coating, and the second coating is an interference light variation coating. The predetermined plating layer hollow-out area is an area where a plating layer is not required to be formed, for example, the first surface relief structure layer includes at least two kinds of surface relief structures, in the at least two kinds of surface relief structures, an aspect ratio of one surface relief structure is greater than an aspect ratio of at least one other surface relief structure except the surface relief structure, the area where the plating layer is not required to be formed is an area where the surface relief structure having the largest aspect ratio is located, and the aspect ratio of the surface relief structure of the predetermined plating layer hollow-out area is the aspect ratio of the surface relief structure having the largest aspect ratio.

Optionally, in an embodiment of the present invention, forming a first plating layer on at least a partial region of a surface of the first surface relief structure layer and/or forming a second plating layer on at least a partial region of a surface of the second surface relief structure layer, and completing a pre-plating printing hollow, and implementing the printing hollow by using a positioning printing method, specifically including: positioning overprinting ink or a coating on an area, which does not need to form a plating layer, of the surface relief structure layer; evaporating and plating a plating layer on the surface relief structure layer; and placing the optical anti-counterfeiting element in a solution to clean the ink or the coating so that the coating is reserved only in the area of the surface relief structure layer where the coating is preset, wherein the surface relief structure layer comprises a first surface relief structure layer and/or a second surface relief structure layer, and the area where the coating is preset is the area of the surface relief structure layer except for the area where the coating is not required to be formed.

Optionally, in an embodiment of the present invention, forming a first plating layer on at least a partial region of a surface of the first surface relief structure layer and/or forming a second plating layer on at least a partial region of a surface of the second surface relief structure layer, and completing the positioning printing hollow in another manner includes: completing the evaporation plating on the surface of the surface relief structure layer; positioning overprinting a plating layer protective ink or coating on an area, needing to keep the plating layer, on the surface of the surface relief structure layer; placing the optical anti-counterfeiting element in an acidic or alkaline solution to clean the coating to protect the ink or the coating so that the coating is reserved in an area where the coating is preset to be reserved on the surface of the surface relief structure layer; wherein the surface relief structure layer comprises a first surface relief structure layer and/or a second surface relief structure layer.

The specific working principle and benefits of the preparation method of the optical anti-counterfeiting element provided by the embodiment of the invention are similar to those of the optical anti-counterfeiting element provided by the embodiment of the invention, and are not repeated here.

Optionally, in an embodiment of the present invention, the first surface relief structure layer and the second surface relief structure layer may be formed by UV ultraviolet printing. The UV ultraviolet imprinting coating comprises components such as a photoinitiator, an active monomer, a film-forming resin and the like. And when the UV coating is coated, the surface relief structure layer is completed, and the surface relief structure layer comprises the holographic diffraction structure, the dynamic blazed grating, the high depth-to-width ratio hollow structure and the like. The structural section of the surface relief structure layer can be a cosine structure, a sawtooth structure, a square wave structure, a cylindrical structure, a spherical structure, a pyramid structure, or the like, or a combination of the structures described herein. In order to realize the precise hollow of the single-layer metal reflection coating or the interference light variation coating, at least one of the two surface relief structure layers comprises at least two optical structures with larger depth-height ratio difference. For example, the first surface relief structure layer 2 of fig. 3 includes a relatively flat holographic diffraction structure (region a1) and a first high aspect ratio hollow structure (region b1), and the two optical structures have a relatively large aspect ratio difference or a relatively large volume difference, so that selective plating hollowing of the optical structures can be realized.

In addition, taking the structure in which the first surface relief structure layer and the second surface relief structure layer are located on two sides of the substrate as an example, the effective optical structure regions in the two surface relief structure layers, such as regions a1 and a2 in fig. 3, can be designed and achieve double-sided synchronous positioning registration with a positioning accuracy of 0.05-2 mm, preferably 0.1-0.5 mm. Therefore, by using the precise hollow-out technology, specific front and back multi-angle multi-vision characteristics can be formed, which will be further described below.

In the optical anti-counterfeiting element provided by the embodiment of the invention, the surfaces of the first surface relief structure layer and the second surface relief structure layer are both provided with local metal or metal compound coatings, and preferably, at least one of the two coatings respectively arranged on the surfaces of the two surface relief structure layers is an interference light variable coating. For example, as shown in fig. 3, a single metal reflective coating 6 and an interference light variation coating 7 are respectively disposed on the surfaces of the two surface relief structure layers. The surface of the first surface relief structure layer 2 is provided with a single-layer metal reflective coating 6 comprising metals such as aluminum, silver, copper and the like or alloys thereof, and the surface of the second surface relief structure layer 4 is provided with an interference light variable coating 7 comprising a reflective layer, a dielectric layer and an absorption layer. The reflecting layer comprises metals such as aluminum, silver, copper and the like or alloys thereof, the dielectric layer comprises metal fluorides such as magnesium fluoride, silicon oxide, zinc sulfide, titanium nitride and the like, metal oxides, metal sulfides, metal nitrides and the like, and the absorbing layer comprises metals such as chromium, nickel and the like or alloys thereof.

In the optical anti-counterfeiting element provided by the embodiment of the invention, the local plating layers on the surfaces of the two surface relief structure layers are realized by a hollow-out process. The hollowing process can comprise a plating layer surface positioning printing protective glue hollowing process, a printing hollowing process before plating and an optical structure selective precise hollowing process. Optionally, at least one of the two local plating layers respectively formed on the two surface relief structure layers adopts a precise hollow-out process. For example, as shown in fig. 3, the two local plating layers of the two surface relief structure layers are selectively hollowed out by a precise hollowing process. The area a1 in the first surface relief structure layer 2 is designed and selected to be a relatively gentle holographic diffraction structure, and the area b1 is a holographic-like structure with a relatively large depth-to-width ratio, and due to the significant difference of the specific volume (depth-to-width ratio), a selective plating protective layer can be formed on the area a1 by the technical method of 201510954137.5, so that the accurate positioning and hollowing of the area b1 can be realized. The protective layer 8 may include one or more of a transparent polymer coating, a color coating (the color coating may be opaque, translucent or transparent), a liquid crystal optically variable coating, and an OVI optically variable ink. Similar to the precise hollowing of the local plating of the first surface relief structure layer 2, the interference light variable plating 7 corresponding to the area a2 in the second surface relief structure layer 4 is selectively retained, while the area b2 completes the complete hollowing of the interference light variable plating 7 in the manner of 201310598261.3, and the area b2 is a transparent area without any plating residue.

In addition, in the embodiment of the invention, the local plating layers respectively formed on the surfaces of the first surface relief structure layer and the second surface relief structure layer can be finished in a printing and hollowing mode before plating. Next, the optical security element shown in fig. 3 will be described by taking an example in which the interference light variable plating layer 7 is formed on the surface of the second surface relief structure layer 4. After the UV imprinting replication of the second surface relief structure layer 4, the ink or coating that can be cleaned with solution (water, alkaline aqueous solution, acidic aqueous solution or other solvent type solution) is overprinted in the surface region b2 of the surface relief structure layer 4, and then the ordered evaporation of the interference light variable plating layer 7 is completed, and after the cleaning with solution, the accurate hollowing of the local plating layer (region b2) is completed without any plating layer residue.

In addition, in the embodiment of the present invention, the local plating layers respectively formed on the surfaces of the first surface relief structure layer and the second surface relief structure layer may also be formed by a positioning printing hollow-out manner. Next, an optical security element shown in fig. 3 will be described by taking an example in which a single metal reflective plating layer 6 is formed on the surface of the first surface relief structure layer 2. After the first surface relief structure layer 2 is copied by UV imprinting, a single-layer metal reflective coating, such as an aluminum layer, is evaporated on the surface; and then positioning overprint plating protective ink or coating on the surface area a1 of the surface relief structure layer 2, cleaning with solution (water, alkaline aqueous solution, acidic aqueous solution or other solvent solutions) to complete accurate hollowing of the local plating layer (area a2), and reserving the metal plating layer on the surface of the surface relief structure layer of the area a 1.

In the embodiment of the invention, a protective layer, a hot melt adhesive layer, other printing ink or anti-counterfeiting printing ink and the like can be arranged on the surfaces of the two surface relief structure layers and the local plating layer which are partially hollowed out according to the needs of products, and a stripping layer is additionally arranged between the substrate and the surface relief structure layer, so that the application on substrates such as paper money, plastics, composite substrates and the like is realized.

The following description will take the example of the preparation of the optical security element shown in fig. 3. As shown in fig. 8, fig. 8 is a schematic process diagram of manufacturing the optical security element shown in fig. 3. First, the substrate 1 is subjected to simultaneous or stepwise replication of the two surface relief structure layers, and UV printing can be used to ensure complete replication of each optical structure (see fig. 8A). Subsequently, the evaporation of the single-layer coating is performed on the surface of the first surface relief structure layer 2, for example, a metal reflective aluminum layer 10 is added on all or at least a part of the surface of the first surface relief structure layer 2 by using a vacuum evaporation apparatus (for example, in this embodiment, the single-layer metal reflective coating is a metal reflective aluminum layer), and a dealumination protective layer 11 with a low dry coating weight is applied, and the metal reflective aluminum layer 10 is protected mainly in the area a1 (fig. 8B). The surface of the second surface relief structure layer 4 is coated with an interference light variable coating layer 7 (fig. 8C), which may be a multilayer interference light variable coating layer such as Al/SiO2/Cr, for example. And adjusting the technological parameters such as the thickness of the coatings on the surfaces of the two surface relief structure layers and the like and the hollowing technological parameters, and simultaneously realizing the selective and accurate hollowing of the two coatings. The hollowing process can adopt one or a combination of alkaline washing hollowing, water washing hollowing, acid washing hollowing and the like to fulfill the aim of selectively hollowing the optical structure. According to the application requirement of the product, a protective layer and a hot melt adhesive layer are added on the upper surface and the lower surface of the optical anti-counterfeiting element, and a stripping layer is added between the substrate and the surface relief structure layer. For example, the optical anti-counterfeiting element is applied to base materials such as plastic banknotes and paper banknotes with transparent windows in the form of an optical anti-counterfeiting window film-coated wide strip, namely, a protective layer with high temperature and high pressure resistance is added on the upper surface of the optical anti-counterfeiting element and is adjacent to the second surface relief structure layer 4 and the local interference light variable coating layer 7; and a protective layer and a hot stamping glue layer are added on the lower surface of the optical anti-counterfeiting element, so that the optical anti-counterfeiting element is used for protecting a coating and hot stamping the surface of a base material such as plastic money.

In addition, another aspect of the embodiments of the present invention provides an optical anti-counterfeiting product, which includes the optical anti-counterfeiting element described in the above embodiments.

Alternatively, the optical anti-counterfeiting product comprises a commodity identification, a securities, a banknote, a credit card, an identification card or a passport, etc.

Optionally, the optical anti-counterfeiting element can be arranged on the valuable object in an anti-counterfeiting safety line, an anti-counterfeiting window wide strip, an anti-counterfeiting transfer wide strip or an anti-counterfeiting label, especially arranged on a paper money or a plastic money with a transparent or semitransparent window in an anti-counterfeiting window wide strip or anti-counterfeiting label mode, and used for multi-angle multiple identification of front and back reflection and transmission of the window part.

In summary, the first plating layer and the second plating layer are respectively formed on the surfaces of the two surface relief structure layers, and the first plating layer and the second plating layer have an overlapping region, so that different image-text characteristics can be observed when the optical anti-counterfeiting element is observed from the front side and the back side. When the first coating layer is facing the viewer, parts of the second coating layer are masked and vice versa. Therefore, the multi-angle identification of the optical anti-counterfeiting element is realized, the optical anti-counterfeiting element can present multiple visual appearances, and the anti-counterfeiting performance of the optical anti-counterfeiting element is improved. If the local layers of the two surface relief structures are locally different, the optical anti-counterfeiting element can further present different visual appearances, and the anti-counterfeiting identification performance of the optical anti-counterfeiting element is improved. The local plating layer structure further increases the image-text characteristics of the optical anti-counterfeiting element and improves the anti-counterfeiting performance of the optical anti-counterfeiting element. The interference light variable coating enables the optical anti-counterfeiting element to present the characteristic of special color change when being observed, and the anti-counterfeiting performance of the optical anti-counterfeiting element is further improved. In the surface relief structure layer, undulation structures with different depth-to-width ratios exist, and the formation of accurate hollowing is facilitated.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the embodiments of the present invention are not limited to the details of the above embodiments, and various simple modifications can be made to the technical solutions of the embodiments of the present invention within the technical idea of the embodiments of the present invention, and the simple modifications all belong to the protection scope of the embodiments of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, the embodiments of the present invention do not describe every possible combination.

In addition, any combination of various different implementation manners of the embodiments of the present invention is also possible, and the embodiments of the present invention should be considered as disclosed in the embodiments of the present invention as long as the combination does not depart from the spirit of the embodiments of the present invention.

Claims

1. An optical security element, comprising:

a transparent substrate;

a first surface relief structure layer located on at least a partial region of the substrate surface;

a first plating layer formed on at least a partial region of a surface of the first surface relief structure layer;

the second surface relief structure layer is formed on the surface of the first plating layer and covers at least partial area of the substrate;

and the second plating layer is formed on at least partial area of the surface of the second surface relief structure layer, and the second plating layer and the first plating layer have an overlapping area.

2. An optical security element, comprising:

a transparent substrate;

a first surface relief structure layer located on at least a partial region of one side surface of the substrate;

a second surface relief structure layer formed on at least a partial region of the other side surface of the substrate opposite to the one side;

3. A preparation method of an optical anti-counterfeiting element is characterized by comprising the following steps:

forming a first surface relief structure layer on at least a partial region of the substrate surface;

forming a first plating layer on at least a partial region of the surface of the first surface relief structure layer;

forming a second surface relief structure layer on the surface of the first plating layer, wherein the second surface relief structure layer covers at least partial area of the substrate; and

forming a second plating layer on at least a partial region of a surface of the second surface relief structure layer,

wherein the second plating layer and the first plating layer have an overlapping region.

4. A preparation method of an optical anti-counterfeiting element is characterized by comprising the following steps:

forming a first surface relief structure layer on at least a partial region of one side surface of the substrate;

forming a second surface relief structure layer on at least a partial region of the other side surface of the substrate opposite to the one side; and

forming a second plating layer on at least a partial region of the surface of the second surface relief structure layer;

5. The optical security element according to claim 1 or 2 or the production method according to claim 3 or 4, wherein at least one of the first plating layer and the second plating layer is an interference light variable plating layer.

6. The optical security element or the preparation method according to claim 5, wherein the interference light variation coating comprises a reflecting layer, a dielectric layer and an absorbing layer.

7. The optical anti-counterfeiting element or the preparation method according to claim 5, wherein the first plating layer is a single-layer metal reflective plating layer or a high-refractive-index dielectric plating layer, and the second plating layer is the interference light variable plating layer.

8. An optical security element according to claim 7, further comprising:

the first coating is formed on the surface of the first plating layer or the surface of the first surface relief structure layer; and/or

A second coating layer formed on the surface of the second plating layer or the surface of the second surface relief structure layer,

wherein the first coating and/or the second coating is opaque, translucent, or transparent, the first coating and/or the second coating comprising at least one of: color polymer coating, liquid crystal optically variable coating and OVI optically variable ink.

9. The method of claim 7, further comprising:

forming a first coating on the surface of the first plating layer or the surface of the first surface relief structure layer; and/or

Forming a second coating on the surface of the second plating layer or the surface of the second surface relief structure layer,

10. The optical security element according to claim 1 or 2 or the production method according to claim 3 or 4, wherein at least one of the first surface relief structure layer and the second surface relief structure layer comprises at least two surface relief structures, an aspect ratio of one of the at least two surface relief structures is larger than an aspect ratio of at least one surface relief structure other than the one surface relief structure, and the plating layer is formed on the at least one surface relief structure.

11. An optical security element or a method of manufacture as claimed in claim 10 wherein the structural cross-section of the surface relief structure layer comprising the at least two surface relief structures is any one or a combination of: cosine structures, sawtooth structures, square wave structures, cylindrical structures, spherical structures, and pyramid structures.

12. An optical security element or a production method according to claim 10, wherein the at least two surface relief structures include a first surface relief structure and a second surface relief structure, and an aspect ratio of the first surface relief structure is smaller than an aspect ratio of the second surface relief structure, wherein the first surface relief structure is a holographic diffraction structure or a dynamic blazed grating, and the second surface relief structure is a preset hollow structure.

13. The method of claim 10, wherein forming a first plating layer on at least a portion of a surface of the first surface relief structure layer and/or forming a second plating layer on at least a portion of a surface of the second surface relief structure layer comprises:

evaporating a first coating on the first surface relief structure layer, wherein a coating is not added on the first coating or a dealuminizing protective layer with the dry coating weight smaller than a first preset value is coated on the first coating, and the first preset value is related to the depth-to-width ratio of the surface relief structure of a hollow area of the preset coating in the first surface relief structure layer;

evaporating the second plating layer on the second surface relief structure layer; and

hollowing out the optical security element by at least one of: alkali washing hollowing, water washing hollowing and acid washing hollowing,

the first coating is a single-layer metal reflection coating, and the second coating is an interference light variable coating.

14. The production method according to claim 3 or 4, wherein forming a first plating layer on at least a partial region of the surface of the first surface relief structure layer and/or forming the second plating layer on at least a partial region of the surface of the second surface relief structure layer comprises:

positioning overprinting ink or a coating on an area, which does not need to form a plating layer, of the surface relief structure layer;

evaporating and plating a plating layer on the surface relief structure layer; and

placing the optical anti-counterfeiting element in a solution to clean the ink or the coating so that the coating is only reserved in the area where the surface relief structure layer is preset to be coated,

wherein the surface relief structure layer comprises the first surface relief structure layer and/or the second surface relief structure layer.

15. A method according to claim 3 or 4, wherein forming the first plating layer on at least a partial area of a surface of the first surface relief structure layer and/or forming the second plating layer on at least a partial area of a surface of the second surface relief structure layer comprises:

completing the evaporation plating on the surface of the surface relief structure layer;

positioning overprinting a plating layer protective ink or coating on an area of the surface relief structure layer where the plating layer is required to be reserved; and

placing the optical anti-counterfeiting element in an acidic or alkaline solution to clean the plating layer protective ink or coating so that the plating layer is reserved on the surface of the surface relief structure layer, wherein the area of the plating layer is preset to be reserved;

16. An optical security product comprising an optical security element according to any one of claims 1 to 12.