# US 5,348,677 A · Electro-optical liquid crystal display element

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- Number: US 5,348,677 A
- Document ID: US5348677A
- Status: Granted
- Kind: A
- Application number: 07/963,369
- Filed: 1992-10-20
- Granted: 1994-09-20
- Earliest claimed: 1987-04-28
- Assignees: Merck Patent GmbH
- Inventors: Eike Poetsch; Hans A. Kurmeier; Rudolf Eidenschink; Georg Weber; Andreas Wachtler
- Web page: https://patentgrep.com/patent/US5348677A

## CPC

- C09K 19/3469: {Pyrimidine with a specific end-group other than alkyl, alkoxy or -C*-}
- C09K 19/3001: {Cyclohexane rings}
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

The invention relates to an electro-optical liquid crystal display element containing a dielectric with at least two liquid-crystalline components, wherein the dielectric, for shortening the switching times, contains at least one fluorine-containing compound of the formula I R.sup.1 --(A.sup.1 --Z.sup.1).sub.m --A.sup.2 --R.sup.2 I wherein the radicals R.sup.1, R.sup.2, A.sup.1, A.sup.2, Z.sup.1 and m have the meaning given in claim 1.

## Claims

### Claim 1

An electrooptical liquid crystal display element, containing a dielectric with at least two liquid crystalline components, which dielectric comprises at least one fluorine-containing compound of the formula I
R.sup.1 --(A.sup.1 --Z.sup.1).sub.m --A.sup.2 --R.sup.2 I
wherein
R.sup.1 is H, F, Cl, Br, --CN, --NCS or an unsubstituted straight-chain alkyl group having 1-15 C atoms, in which one or two CH.sub.2 groups are optionally replaced by --O--, --CO--, --O--CO--, --CO--O--, --C.tbd.C--, or --CH.dbd.CH--, no 2 heteroatoms being linked to one another;
R.sup.2 is perfluoroalkoxy of not more than 15 carbon atoms, and having at least 2 CF2 groups in which one or more CF.sub.2 groups are optionally replaced by --CF.dbd.CF--,
A.sup.1 is 1,4-phenylene which is unsubstituted or substituted by one or two F or Cl atoms or CH.sub.3 groups or CN groups, and in which one or two CH Groups are optionally replaced by N atoms; 1,4-cyclohexylene in which one or two non-adjacent CH.sub.2 groups are optionally replaced by O atoms or S atoms; piperidine-1,4-diyl; 1,4-bicyclo[2.2.2]octylene, unsubstituted or CN-- substituted decahydronaphthaline-2,6-diyl or 1,2,3,4-tetrahydronaphthaline-2,6-diyl;
A.sup.2 is 1,4-phenylene which is substituted by one or two F atoms;
m is 1, 2, or 3; and
Z.sup.1 is --CO--O--, --O--CO--, --OCH.sub.2 --, --CH.sub.2 O--, --CH.sub.2 CH.sub.2 -- or a single bond,
it being possible for multiple groups A.sup.1 to be identical or different and for multiple groups Z.sup.1 to be identical or different in the case where M=2 or 3, whereby said element is based on the twisted cell, guest-host, deformation of aligned phase, dynamic scattering, SBE or STN effects.

### Claim 2 (depends on 1)

An electrooptical liquid crystal display element according to claim 1, wherein
R.sup.2 is perfluoroalkoxy of 2-15 carbon atoms;
A.sup.1 is 1,4-phenylene which is unsubstituted or substituted by one or two F atoms, and in which one or two CH groups are optionally replaced by N atoms, 1,4-cyclohexylene in which one or two non-adjacent CH.sub.2 groups are optionally replaced by O atoms;
Z.sup.1 is --CH.sub.2 CH.sub.2 -- or a single bond,
it being possible for multiple groups A.sup.1 to be identical or different and for multiple groups Z.sup.1 to be identical or different in the case where M=2 or 3.

### Claim 3 (depends on 1)

An electrooptical liquid crystal display element according to claim 1 wherein
R.sup.2 is --OC.sub.2 F.sub.5.

### Claim 4 (depends on 2)

An electrooptical liquid crystal display element according to claim 2, wherein
R.sup.2 is --OC.sub.2 F.sub.5.

### Claim 5

AN electrooptical liquid crystal display element, containing a dielectric with at least two liquid crystalline components, wherein the dielectric comprises at least one fluorine-containing compounds which is:
p-[trans-4-(trans-4-methylcyclohexyl)cyclohexyl]pentafluoroethoxybenzene,
p-[trans-4-(trans-4-ethylcyclohexyl)cyclohexyl]pentafluoroethoxybenzene,
p-[trans-4-(trans-4-propylcyclohexyl)cyclohexyl]pentafluoroethoxybenzene,
p-[trans-4-(trans-4-butylcyclohexyl)cyclohexyl]pentafluoroethoxybenzene,
p-[trans-4-(trans-4-pentylcyclohexyl)cyclohexyl]pentafluoroethoxybenzene,
p-[trans-4-(trans-4-hexylcyclohexyl)cyclohexyl]pentafluoroethoxybenzene, or
p-[trans-4-(trans-4-heptylcyclohexyl)cyclohexyl]pentafluoroethoxybenzene,
and wherein said element is based on the twisted cell, guest-host, deformation of aligned phase, dynamic, scattering SBE or STN effect.