Anti-counterfeit film with an amphichroic pattern and a preparation method thereof

Abstract

An anti-counterfeit film comprising an amphichroic pattern is prepared by (1) mixing a polymerizable liquid crystal material of chiral structure and a photoinitiator, blade-coating the mixture on a base film and then drying; (2) partially exposing the resulting material produced in step (1) using a positioned UV lamp, then drying and exposing in an UV radiation to obtain a desired film. The film prepared by the method has an amphichroic pattern which typically presents a red and green picture when being vertically observed, the original red and green respectively changes into green and blue when being observed at a certain incline angel. The anti-counterfeit film is characterized by obvious color change, easy identification, practicability and convenience, thus facilitating promotion and application.

Dependencies are inferred from the claim text.