摘要:
Liquid-crystalline compounds of the formula I ##STR1## R is H, an alkyl or alkylene radical, Z.sup.1 and Z are each, independently of one another, --CH.sub.2 CH.sub.2 --, --CH.dbd.CH--,--C.tbd.C-- or a single bond, and one of the radicals Z.sup.1 and Z is alternatively --(CH.sub.2).sub.4 -- or --CH.dbd.CH--CH.sub.2 CH.sub.2 --, A is trans-1,4-cyclohexylene in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by --O--, A.sup.1 is trans-1,4-cyclohexylene in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by --O--, or is 1,4-phenylene which is unsubstituted or monosubstituted or disubstituted by fluorine and/or Cl atoms and in which, in addition, one or two CH groups may be replaced by N, W is --O--, Q is a single bond, m, o, s, r and t are as defined below, Y is F, Cl, OCF.sub.3, CHF.sub.2, OCHF.sub.2 or OCHF, and can be CF.sub.3, are suitable as components for liquid-crystalline media.
摘要:
The invention relates to the use of compounds of the formula IR.sup.1 --Q.sup.1 --A--(A.sup.2).sub.q --R.sup.2 Iwherein ##STR1## and R.sup.1, R.sup.2, Q.sup.1, Q.sup.2 and q have the meaning specified in claim 1, as components of smectic liquid-crystalline phases, and also smectic liquid-crystalline phases, in particular chiral tilted smectic phases containing compounds of formula I.
摘要:
Heterocyclic 1,2-difluorobenzene derivatives of the formula I ##STR1## in which R.sup.1 and R.sup.2, in each case independently of one another, are an alkyl groups (sic) having 1-15 C atoms in which, in addition, one or more CH.sub.2 groups may be replaced by a divalent radical selected from the group comprising --O--, --S--, --CO--, --O--CO--, --CO--O--, --CH.dbd.CH-- and --C.tbd.C--, where two heteroatoms are not linked directly to one another,A.sup.1 and A.sup.2, in each case independently of one another, are a 1,4-phenylene group which is unsubstituted or monosubstituted or polysubstituted by fluorine, and in which, in addition, one or two CH groups may be replaced by N, or are a 1,3,4-thiadiazole-2,5-diyl group or a trans-1,4-cyclohexylene group,m and n are each 0 or 2,o is 0 or 1, andp is 0, 1 or 2,where (o+p) is 1, 2 or 3 and, in the case where p=2, the A.sup.2 groups and n may be identical or different with the proviso that at least one of the groups A.sup.1 and A.sup.2 is a 1,3,4-thiadiazole-2,5-diyl group or an unsubstituted or substituted 1,4-phenylene group in which one or two CH groups have been replaced by N,are suitable as components of liquid-crystalline phases.
摘要:
Chiral, tilted, smectic liquid-crystal phases containing at least two liquid-crystal components and at least one chiral doping agent, at least one liquid-crystal component being a compound having the structural unit 2,3-difluoro-1,4-phenylene, are distinguished by a very low viscosity and advantageous switching times.
摘要:
The invention relates to a liquid-crystalline medium for electrooptical display elements based on the ECB effect, containing two components A and B which themselves comprise one or more individual compounds, component A having clearly negative dielectric anistropy and giving the liquid-crystalline phase a dielectric anistrophy of .ltoreq.-0.3, and component B having pronounced nematogeneity and a viscosity of not more than 30 mPa.s at 20.degree. C., characterized in that component A contains one or more compounds containing a structural element ##STR1##
摘要:
The invention relates to a nematic liquid-crystal composition for active matrix displays with high voltage holding ratio and extremely good low temperature stability.
摘要:
The invention relates to methylenecyclobutane derivatives of the formula I ##STR1## in which R.sup.1, A.sup.1, A.sup.2, Z.sup.1, Z.sup.2, L.sup.1, L.sup.2, X, Y and m are as defined in claim 1, and to the use thereof as a component of liquid-crystalline media for electrooptical displays.
摘要:
The invention relates to a nematic liquid-crystal composition for active matrix displays with high voltage holding ratio and extremely good low temperature stability.
摘要:
2,5-Disubstituted heterocycles of the formula I ##STR1## in which R.sup.1 and R.sup.2, each independently of one another, are alkyl, alkenyl or oxaalkyl having up to 12 C atoms,L.sup.1 and L.sup.2, each independently of one another are H or F,Y is --O--, --CO--O--, --O--CO-- or a single bond,m is 1 or 2,Z is H, F, OH or alkyl having up to 5 C atoms, andQ is --O--, --O--CO--, or if Z is fluorine or hydroxyl, is also be a single bondare suitable as components of ferroelectric mixtures.