Method of producing polymer layer with latent polarized image

摘要

The present invention provides a method of producing a latent polarized image having high contrast characteristics with no apparent contours or traces of the image under normal visualization. A polymer solution is prepared in an organic solvent, and then applied onto a light-reflecting substrate. The polymer layer is dried to produce an optically isotropic polymer layer and anisotropic images are formed on the polymer layer. The polymer solution's concentration is from 5 to 30% by weight, and the images are formed by application of micro-lines by thermo-mechanical means, having depths from 1 to 3 μm and being separated from one another by 4 to 6 μm at a process rate from 10 to 50 m/min. The thermomechanical means operates at a temperature that is 10 to 60% less than the polymer melting/disintegration temperature and contacts the polymer layer to form micro-lines for 0.015 to 0.650 msec.