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US 5,178,791 AGranted
Halogenated diphenyldiacetylene liquid crystals
AssigneeDisplaytech, Inc.
InventorsMichael D. Wand, Sean D. Monahan
Life of this patent
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AssigneeDisplaytech, Inc.
InventorsMichael D. Wand, Sean D. Monahan
Estimating the term…
The present invention provides liquid crystals that are 3,3'-dihalogenated diphenyldiacetylenes of the general formula: ##STR1## where X and Y are, independently of one another, a halogen atom and T.sub.1 and T.sub.2, independently of one another are alkyl or alkenyl or alkoxy tail groups, R.sub.1, R.sub.2, or OR.sub.3, respectively, wherein R.sub.1 and R.sub.3, independently of one another, are straight-chain or branched alkyl groups having three to twenty carbon atoms and R.sub.2 is a mono or diene which may be branched or straight-chain having three to twenty carbon atoms. R.sub.1, R.sub.2, or R.sub.3 may be substituted with one or more halogens, particularly fluorines, except that the C-1 carbon of an OR.sub.3 tail may not be halogenated. One or two non-neighboring CH.sub.2 groups of R.sub.1 or R.sub.3 may be substituted with an O atom, except that the C-1 CH.sub.2 group of an OR.sub.3 tail may not be substituted with an O atom. Liquid crystals in which X=Y=fluorine and T.sub.1 =T.sub.2 are more preferred. Compounds in which R.sub.1, R.sub.2 and R.sub.3 are straight-chain alkyl groups or .omega.-monoene groups are more preferred.
A compound of formula:
The compound of claim wherein R.sub.6 and R.sub.7, independently of one another, are straight-chain alkyl groups having from nine to sixteen carbon atoms.
A FLC material exhibiting a smectic C phase comprising about 75% or more by weight of a mixture of one or more of the compounds selected from the group consisting of 4,4'-didecyloxy-3,3'-difluorodiphenyldiacetylene, 4,4'-diundecyloxy-3,3'-difluorodiphenyldiacetylene and 4,4'-ditetradecyloxy-3,3'-difluorodiphenyldiacetylene.
A FLC host mixture which comprises one or more compounds having the formula:
A FLC material exhibiting a smectic C phase comprising about 75% or more by weight of a mixture of one or more compounds of formula:
A high birefringence FLC material exhibiting a smectic C phase comprising about 30% or more by weight of a mixture of one or more compounds of the formula:
Dependencies are inferred from the claim text.