Thomson-csf

Laurent Bouteiller

Pierre Le Barny

Jean-Pierre Vairon

Disclosed is a method for obtaining composite material comprising a network of cross-linked polymer and fluid molecules. Such materials, using molecules of liquid crystal, are notably used in display screens. The originality of the disclosure lies in the drying, in supercritical phase, of the molecules that have enabled the preparation of the network. Generally, the operation of evaporation drying of the solvent leads to a deterioration of the network structure. With the method according to the invention, the network keeps its initial structure, making it possible to obtain high performance characteristics in scattering of light. Application to display screens and protection for detectors. No abstract figure.

Method for obtaining composite materials based on cross-linked polymer

Disclosed is a novel type of composite electro-optical material based on liquid crystal dispersed in a polymer with reactive functional groups (Y). The originality of this material lies in the chemical modification of the interface between the polymer and the liquid crystal leading to the formation of a composite material comprising a porous network of polymer and liquid crystal molecules in the pores of the network. The polymer possesses reactive functional groups (Y) and functional groups (X) at the interface between the polymer and the liquid crystal. The totality constituted by the functional groups (Y) and the functional groups (X) enables the optimizing of the electro-optical performance characteristics obtained from this type of material. Also disclosed is a method to obtain this composite material as well as a device comprising a material such as this.

Electro-optical material based on polymer-dispersed liquid crystal,

Disclosed is an original method for preparing composite materials for a display screen, these materials containing a polymer, liquid crystal and dye. The present problem is one of inserting molecules of dye into composites of this type. The disclosed method proposes the preparation, in a first step, of a porous film of reticulate polymer. Then, molecules of liquid crystal (XL) and molecules of dye (C) are made to diffuse therein by a polymer-expanding solvent. After evaporation of the solvent, a film of polymer is obtained with inclusions containing liquid crystal (XL) and dye (C) with a wide range of concentrations in liquid crystal, thus making it possible to optimize the performance characteristics in terms of contrast and control voltage of the screen thus made.

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Palaiseau, France

Laurent Bouteiller