Reflective film
AssigneeMerck Patent GmbH
InventorsDavid Coates, Mark Andrew Verrall
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Abstract
The invention relates to a process as described in claim of preparing a reflective film comprising a layer of a polymerized mesogenic material with helically twisted structure, wherein the helix axis is perpendicular to the film plane, and containing regions with varying helical pitch, to a reflective film obtainable by such a process, to the use of such a reflective film as reflective broadband or notch polarizer or as a multicolored film or image in liquid crystal displays, as color filter, in effect pigments, for decorative or security applications, and to a liquid crystal display comprising a liquid crystal cell and a reflective polarizer as described in the foregoing and the following, and optionally further comprising one or more compensaters or polarizers.
Claims14
A process for preparing a reflective film comprising a polymerized mesogenic material with helically twisted structure and varying helical pitch, which comprises polymerizing a polymerizable mesogenic material in its helically twisted mesophase, wherein the pitch variation is achieved by polymerizing at an essentially constant temperature where the polymerizable mesogenic material has a less ordered mesophase and the polymerized material has a more highly ordered thermodynamically stable mesophase.
A process for preparing a reflective film comprising a polymerized mesogenic material with helically twisted structure and varying helical pitch, which comprises polymerizing a polymerizable mesogenic material in its helically twisted mesophase, wherein the pitch variation is achieved by polymerizing a polymerizable mesogenic material comprising
- a) at least one chiral or achiral polymerizable mesogenic compound,
- b) at least one chiral compound, which can also be one of the compounds of component a), d), e) or f),
- c) at least one polymerization initiator,
- d) optionally at least one crosslinking agent,
- e) optionally at least one chain termination or chain transfer agent,
- f) optionally a dye component comprising at least one dye,
- the amount and type of components c) and/or d) and/or e) and/or f) being selected to result in a film having varying pitch.
Dependencies are inferred from the claim text.