A kind of method for preparing optical anti-counterfeiting element

Abstract

The invention provides a method capable of accurately positioning a coating for producing an anti-counterfeiting optical element and aims at overcoming the defects that the efficiency is low, and fine mapping, metal removal and hollowing cannot be realized in the prior art for producing the anti-counterfeiting element. The method comprises the following steps: forming an undulating structural layer comprising at least a first undulating structural layer area and a second undulating structural layer area on the surface of a substrate, wherein the ratio of the surface area to the apparent area of the first undulating structural layer area is greater than the ratio of the surface area to the apparent area of the second undulating structural layer; forming a first coating on at least one part of the first undulating structural layer area and forming a second coating on at least one part of the second undulating structural layer area; forming protecting layers which can be heated for sublimating on the at least one part of the first coating and on the at least one part of the second coating, wherein the thickness of the protecting layer on the first coating is smaller than that of the protecting layer on the second coating; heating to sublimating the protecting layers until the protecting layer on the first coating is completely sublimated and the protecting layer on the second coating is not completely sublimated; hollowing out the coating part which is not protected by the protecting layers.

Description

technical field [0001] The invention relates to the field of optical anti-counterfeiting, in particular to a method for preparing an optical anti-counterfeiting element. 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] Among various optical anti-counterfeiting technologies, holographic technology is currently the most widely used optical anti-counterfeiting technology. In order to increase the brightness of the image, the holographic anti-counterfeiting element generally adopts metal coating. Hollowing out the metal coating to form a pattern on the metal coating can greatly improve the visual effect and anti-counterfeiting ability of the optical anti-counterfeiting element. Hollow technol...

AI Technical Summary

Problems solved by technology

[0008] The present invention aims at defects such as low efficiency, difficult quality control, and inability to precisely and accurately locate and remove metal hollowing in the preparation of optical anti-counterfeiting elements in the prior art, and provides a method for preparing optical anti-counterfeiting elements that can overcome these defects

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