Polyimides for anchoring liquid crystals, display devices including same and method for the preparation of said devices
AssigneeNemoptic
InventorsSandrine Lamarque, Jean-Claude Dubois, Didier Gallaire
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Abstract
The present invention relates to novel polyimides derived from 6FDA and from 3,3-dihydroxy-4,4′-diaminobiphenyl and novel polyimides derived from PMDA and from Bis-AP-AF, having alkyl, arylalkyl, heteroarylalkyl, (cycloalkyl)alkyl, fluoroalkyl or siloxane side groups. The present invention also relates to a method of producing nematic liquid-crystal devices, which comprises the steps consisting in: depositing one of the polyimides according to the invention on a substrate; annealing the polyimide in one or more steps; and defining an azimuthal orientation of the polyimide coating.
Claims16
Polyimides for producing low-energy anchoring layers in nematic liquid-crystal cells, according to the following types:
- polyimide derived from 2,2′-bis (3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and from 3,3′-dihydroxy-4, 4′ diaminobiphenyl of formula I:
- in which the radicals R1 and R2, which are identical or different, represent an alkyl, arylalkyl, heteroarylalkyl, (cycloalkyl)alkyl, fluoroalkyl or siloxane radical and n is between 1 and 20;
- polyimide derived from pyromellitic anhydride (PMDA) and from 2,2-bis (3-amino-4-hydroxyphenyl)hexafluoropropane (Bis-AP-AF) of formula II.
- in which the radicals R3 and R4, which are identical or different, have the same meaning as R1 and R2 and n is between 1 and 20;
- and
- copolymers of polyimide (I) and of polyimide (II).
Dependencies are inferred from the claim text.