The Secretary of State for Defence in Her Britannic Majesty's Government

Merck Patent Gesellschaft MIT Beschrankter Haftung

The Secretary of State for Defense in Her Britannic Majesty's Government

Her Majesty's Government of the Uk.

Neil Carr

George W Gray

Beatrice M Andrews

Joachim Krause

Rudolf Eidenschink

Stephen M Kelly

Christine Hogg

Damien Gerard McDonnell

Edward P Raynes

Jennifer Constant

Ring compounds

A novel liquid crystal compound has a formula: ##STR1## where: ##STR2## is a trans-2,5-disubstituted-1,3-dioxan ring or a 2,5-disubstituted-1,3-pyrimidine ring ##STR3## is a 1,4-disubstituted benzene ring optionally containing one or more F, Cl or CH.sub.3 groups as lateral substituents; R.sub.1 is an alkyl group; and X is a terminal group selected from H, CN, Cl, F and R.sub.2 where R.sub.2 is selected from alkyl R.sub.3, alkoxy OR.sub.3, alkylcarbonyloxy OCOR.sub.3 and alkoxycarbonyloxy OCOOR.sub.3.

Liquid crystal compounds

Liquid crystalline phases containing alkylene-type bridges

A liquid crystal composition includes at least one compound of Formula (I) as follows:

A novel liquid crystal compound has a formula: ##STR1## where: ##STR2## is a trans-2,5-disubstituted-1,3-dioxan ring or a 2,5-disubstituted-1,3-imidine ring ##STR3## is a 1,4-disubstituted benzene ring optionally containing one or more F, Cl or CH.sub.3 groups as lateral substituents; R.sub.1 is an alkyl group; and

A liquid crystal material which comprises a mixture of compounds includes at least one low viscosity additive compound of Formula (I) as follows:

Liquid crystal materials

Novel liquid crystal ester compounds exhibiting a low or negative dielectric anisotropy have a structural formula: ##STR1## where R.sub.1 is an alkyl group, R.sub.2 is an alkyl or alkoxy group, ##STR2## is a 1,4-disubstituted bicyclo(2,2,2) octane ring and ##STR3## is a 1,4-disubstituted ring selected from the following: (i) a 1,4-disubstituted bicyclo(2,2,2) octane ring;

Liquid crystal ester compounds exhibiting a low or negative dielectric

Novel liquid crystal compounds exhibiting a low dielectric anisotropy have a structural formula: ##STR1## where R.sub.1 is an alkyl group, R.sub.2 is a group containing an alkyl group R and is either an alkyl group R, an alkoxy group OR, an alkylcarbonyloxy group OCOR or an alkoxycarbonyloxy group OCOOR, R.sub.1 and R containing up to 18 carbon atoms, ##STR2## is a trans-1,4-disubstituted cyclohexane ring ##STR3## or a 1,4-disubstituted bicyclo(2,2,2)octane ring ##STR4## and Ar is a 1,4 disubstituted benzene ring ##STR5## a 3-fluoro-1,4 disubstituted benzene ring ##STR6## or a 2,6 disubstituted naphthalene ring ##STR7## These compounds may be used in liquid crystal mixture compositions for use in a number of known electro-optic effects. The compounds may be prepared by routes in which the individual steps involved are known.

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Hull, United Kingdom

Neil Carr