Polymer film with helically twisted molecular structure

摘要

Polymer film with a helically twisted molecular structure is made by polymerizing an oriented layer of thermochromic, polymerizable, mesogenic material by exposure to actinic radiation while varying the temperature. Polymer film with a helically twisted molecular structure showing at least two reflection peaks, obtained by (A) forming a coating on a substrate or a layer between two substrates of a thermochromic, polymerizable, mesogenic composition containing (a) achiral polymerizable mesogenic compound(s), (b) optionally polymerizable and/or mesogenic chiral compound(s), (c) a polymerisation initiator, and (d) optionally a dye component; (B) orienting the composition so that the axis of the helix is at right angles to the layer; (C) possibly heating at least part of the composition to a specific temperature; (D) polymerizing at least part of the composition with actinic radiation while changing the temperature; (E) possibly repeating step (D) or (D) plus (C) and/or steps (A) and (B); and (F) possibly removing the substrate(s).