Patent ID: 6217948
Filing Date: 2001-04-17
Classification: C09K,G02B,G11B

Abstract:
A polymer film with a helically twisted structure comprising at least one layer exhibiting at least two maxima of the selective reflection wavelength at a single viewing angle, prepared by a processing comprisingA) coating a thermochromic polymerizable mesogenic composition comprising the following componentsa) at least one achiral polymerizable mesogenic compound,b) at least one chiral compound that is optionally also polymerizable and/or mesogenicc) a polymerization initiator, andd) optionally a dye component,on a substrate or between two substrates in the form of a layer,B) aligning the polymerizable mesogenic composition so that the axis of the molecular helix extends transversely to the layer,C) optionally heating at least a part of the aligned composition to a defined temperature,D) polymerizing at least a part of the aligned composition by exposure to actinic radiation,E) optionally repeating step D) alone or together with step C) and/or steps A) and B) at least once, andF) optionally removing the substrate or, if two substrates are present, one or both of the substrates from the polymerized material,characterized in that the temperature of the aligned composition is varied in step D).