Minnesota Mining and Manufacturing Company

3m Innovative Properties Company

Daniel C Snustad

Marc Dudley Radcliffe

Patricia M Savu

Terence D Spawn

Gilbert C Johnson

Michael P Keyes

Steven J Martin

Eugene P Janulis

Kenneth A Epstein

Takashi Amano

John F Kistner

Masakazu Hasegawa

Fluorine-containing, chiral liquid crystal compounds comprise (a) a chiral fluorochemical terminal portion comprising (i) at least one chiral center, which can optionally be heteroatom-substituted; (ii) a terminal fluoroalkyl, fluoroether, perfluoroalkyl, or perfluoroether group; and (iii) an alkylene or fluoroalkylene group optionally containing at least one catenary ether oxygen atom; (b) a chiral or achiral terminal portion consisting of a hydrocarbon or hydrocarbon ether group, and, when chiral, comprising at least one chiral center, which can optionally be heteroatom-substituted; and (c) a central core connecting the terminal portions; the alkylene or fluoroalkylene group of the chiral fluorochemical terminal portion having at least 3 in-chain atoms and being located between the chiral center of the chiral fluorochemical terminal portion and the central core. The compounds have smectic mesophases or latent smectic mesophases and are useful, for example, in liquid crystal display devices.

Liquid crystal compounds having a chiral fluorinated terminal portion

A process for preparing a fluoride from its corresponding alcohol comprises the steps of (a) forming a mixture comprising (i) at least one fluorinated, saturated aliphatic or alicyclic sulfonyl fluoride (for example, perfluorobutanesulfonyl fluoride) and (ii) at least one primary or secondary alcohol; and (b) adding a molar excess of at least one strong, aprotic, non-nucleophilic, hindered, double bond-containing, organic base (for example, 1,8-diazabicyclo&lsqb;5.4.0&rsqb;undec-7-ene (DBU)) to the mixture.

Process for converting an alcohol to the corresponding fluoride

Novel liquid crystal compounds are provided which exhibit less temperature dependent switching properties, for the reliable and consistent operation of liquid crystal devices. The liquid crystal compounds comprise (a) an achiral fluorochemical terminal portion that comprises a terminal fluoroalkyl, fluoroether, perfluoroalkyl, or perfluoroether group; a chiral terminal portion comprising a saturated or unsaturated chiral hydrocarbon or chiral hydrocarbon ether group comprising a chiral center; and a central core connecting the terminal portions; said chiral terminal portion having at least three in-chain atoms (an 'extended group') between said chiral center of the chiral terminal portion and said central core.

Chiral liquid crystal compounds having a fluorinated terminal portion

A tristable liquid crystal display device comprises (a) first and second opposed substrates, at least one bearing an alignment coating and each bearing at least one electrode so as to define one or a plurality of pixels; (b) a tilted smectic or induced tilted smectic liquid crystal composition disposed between the substrates; and (c) a pair of orthogonally disposed polarizers, each having a polarization axis, one polarization axis being aligned with the zero field optical axis of a tilted smectic or induced tilted smectic mesophase of the liquid crystal composition; wherein the substrates are disposed so as to provide an alignment of the liquid crystal composition, which comprises (i) at least one chiral liquid crystal compound; and (ii) at least one achiral liquid crystal compound that can be represented by the following formula:

Tristable liquid crystal display device

A tristable liquid crystal display device comprises (a) first and second opposed substrates, at least one bearing an alignment coating and each bearing at least one electrode so as to define one or a plurality of pixels; (b) a tilted smectic or induced tilted smectic liquid crystal composition disposed between the substrates; and (c) a pair of orthogonally disposed polarizers, each having a polarization axis, one polarization axis being aligned with the zero field optical axis of a tilted smectic or induced tilted smectic mesophase of the liquid crystal composition; wherein the substrates are disposed so as to provide an alignment of the liquid crystal composition, the composition comprising at least one chiral liquid crystal compound that can be represented by the following formula:

Fluorine-containing, chiral liquid crystal compounds comprise (a) a chiral fluorochemical terminal portion containing at least one methylene group and optionally containing at least one catenary ether oxygen atom; (b) a saturated, chiral or achiral, hydrocarbon terminal portion; and (c) a central core connecting the terminal portions. The compounds have smectic mesophases or latent smectic mesophases and are useful, for example, in liquid crystal display devices.

A process for controlling the cone tilt angle of a tilted smectic liquid crystal composition comprises the step of combining (a) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound comprising (i) an aliphatic fluorocarbon terminal portion comprising a terminal fluoroalkyl or fluoroether group and an alkylene group having at least two carbon atoms and containing at least one catenary ether oxygen atom, (ii) an aliphatic hydrocarbon terminal portion, and (iii) a central core connecting the terminal portions; and (b) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound; with the provisos that at least one of the compositions (a) and (b) comprises at least one chiral liquid crystal compound and that the combining of compositions (a) and (b) provides an optically active, tilted chiral smectic liquid crystal composition. The process enables control of cone tilt angle and thereby control of the brightness characteristics of liquid crystal display devices.

Process for controlling cone tilt angle in mixtures of smectic liquid

A process for controlling the cone tilt angle of a tilted smectic liquid crystal composition comprises the step of combining (a) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound comprising (i) an aliphatic fluorocarbon terminal portion comprising a terminal fluoroalkyl or fluoroether group and an alkylene group having at least two carbon atoms and containing at least one catenary ether oxygen atom, (ii) an aliphatic hydrocarbon terminal portion, and (iii) a central core connecting the terminal portions, wherein the alkylene group of the aliphatic fluorocarbon terminal portion is directly linked to the central core by a moiety selected from the group consisting of a covalent bond, --CH.dbd.CH--, and --C.tbd.C--; and (b) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound; with the provisos that at least one of the compositions (a) and (b) comprises at least one chiral liquid crystal compound and that the combining of compositions (a) and (b) provides an optically active, tilted chiral smectic liquid crystal composition. The process enables control of cone tilt angle and thereby control of the brightness characteristics of liquid crystal display devices.

Compounds and process for controlling cone tilt angle in mixtures of

Fluorine-containing liquid crystal compounds comprise a fluorocarbon terminal portion having at least one catenary ether oxygen and a hydrocarbon terminal portion, the terminal portions being connected by a central core. The compounds have smectic or latent smectic mesophases.

Liquid crystal compounds having perfluoroether terminal portions

Fluorine-containing, chiral liquid crystal compounds comprise (a) an aliphatic fluorocarbon terminal portion containing at least two catenary ether oxygen atoms; (b) a chiral, aliphatic hydrocarbon terminal portion; and (c) a central core connecting the terminal portions. The compounds have smectic mesophases or latent smectic mesophases and are useful, for example, in liquid crystal display devices.

Chiral liquid crystal compounds having a perfluoroether terminal portion

A process for controlling layer spacing in mixtures of smectic liquid crystal compounds comprises the step of combining a liquid crystal composition having a net negative thermal layer expansion in at least one tilted (or latent tilted) smectic mesophase and a liquid crystal composition having a net positive thermal layer expansion in at least one tilted (or latent tilted) smectic mesophase, each of the compositions comprising at least one smectic or latent smectic liquid crystal compound. The process enables control of layer spacing in the tilted smectic mesophase(s) and thereby control or suppression of chevron layer geometry.

Process for controlling layer spacing in mixtures of smectic liquid

Fluorine-containing, chiral and achiral liquid crystal compounds comprise (a) an aliphatic fluorocarbon terminal portion comprising a perfluorinated or partially-fluorinated alkylene group and a terminal hydrocarbon alkyl group, the groups optionally containing at least one catenary ether oxygen atom; (b) an aliphatic hydrocarbon terminal portion; and (c) a central core connecting the terminal portions. The compounds have smectic mesophases or latent smectic mesophases and are useful, for example, in liquid crystal display devices.

Growing community of inventors

Woodbury, MN, United States of America

Daniel C Snustad