Patent ID: 8227024

Claim:
A method of producing a polymer layer with a latent polarized image including the steps of preparing a polymer solution in an organic solvent, the application of said solution on a light-reflecting substrate, drying said solution resulting in the production of an optically isotropic polymer layer and producing there on the said polymer layer of image generating areas having anisotropic properties, wherein the concentration of a polymer solution is from 5 to 30% by weight, and the areas having anisotropic properties are generated by the operation of a thermomechanical means upon the polymer layer by application on said polymer layer of micro-lines having the depth from 1 to 3 μm, said lines being separated from one another by the distance from 4 to 6 μm or more and the application rate of said lines is from 10 to 50 m/min, wherein the temperature of the thermomechanical means being less than the temperature of polymer melting or decomposition by from 10 to 60% and the duration of contacting of the thermomechanical means with said polymer layer is from 0.015 to 0.650 msec.