Optical anti-counterfeiting element and manufacturing method thereof

Abstract

The invention discloses an optical anti-counterfeiting element and a manufacturing method thereof. The method comprises the steps that a fluctuating structural layer (2) is formed on a base material (1), and the fluctuating structural layer (2) at least comprises a first area and a second area, wherein the first area is of a first fluctuating structure, and the second area is adjacent to the first area and is of a second fluctuating structure; the second fluctuating structure is provided with a side wall, wherein the included angle formed between the plane of the base material (1) and the side wall is larger than 45 degrees, and the depth-to-width ratio of the second fluctuating structure is smaller than 0.3; a clad layer (3) is formed on the fluctuating structural layer (2); and the clad layer (3) is arranged in the clad layer removal environment till the clad layer (3) on the second area is stripped from the fluctuating structural layer (2).

Description

Technical field [0001] The invention relates to the field of optical anti-counterfeiting, in particular to an optical anti-counterfeiting element and a manufacturing method thereof. Background technique [0002] In order to prevent counterfeiting by means of scanning and copying, optical anti-counterfeiting technology is widely used in various high-security or high-value-added printed materials such as banknotes, credit cards, passports, securities and product packaging, and has achieved very good results. [0003] In various optical anti-counterfeiting technologies, in order to increase the brightness of the image, the anti-counterfeiting element generally adopts a metal coating or an inorganic or organic coating with a high refractive index. Hollowing out the plating layer to form a pattern can greatly improve the visual effect and anti-counterfeiting ability of the optical anti-counterfeiting element. [0004] There are generally two traditional techniques for hollowing out the c...

AI Technical Summary

Problems solved by technology

However, it is very difficult to make the mask layer in the second region have an opening structure while keeping the mask layer in the first region intact and continuous.

In fact, the density of the mask layer formed by evaporating inorganic compound materials is often not good, and a hole structure will be formed, so the partial reflective layer in the first region will still be damaged in the final anti-reflective layer process, forming tiny void defect

In addition, the magnesium fluoride formed by this method has a microflaky structure, so the edge of the image of the anti-reflection layer obtained is not fine, and it is impossible to form an extremely fine image, for example, the size is less than 10 microns

Similarly, when using this method, the transfer of microstructures with large aspect ratios (especially when using thermoplastic resin materials) often results in incomplete transfer of microstructures.

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