BigPatents India

A shrinkable iridescent film constitutes an oriented multilayer co extruded iridescent film having at least 10 generally parallel, very thin layers of substantially uniform thickness in which the contiguous adjacent layers are of heat shrinkable thermoplastic resinous material, each of which is heat shrinkable in at least one dimension in the plane of the film, the continuous adjacent layers being substantially uniformly shrinkable so as to have refractive indexes which differ by at least 0.03. Selecting appropriate thermoplastic resinous materials to make the shrinkable film, co extruding them into a thick film and then subjecting the film to orientation below the heat set temperature of the resinous materials. (FIG. 1 )