摘要:
Carbonitriles of the formula I ##STR1## wherein R.sup.1 and R.sup.2 are each an alkyl group having 1-12 C atoms and wherein one or two CH.sub.2 groups/can be groups which are not adjacent replaced by --O--, --O--CO--, --CO--O-- and/or --CH.dbd.CH--, andA.sup.1 is a H or ##STR2## is a group of the formula 1 ##STR3## wherein R.sup.3 has one of the meanings of R.sup.1, can be used as components of liquid crystal phases.
摘要:
A nematic liquid crystalline medium having at least two liquid crystalline components with at least one being of formula I ##STR1## wherein R is H, a straight-chain alkyl or alkenyl radical having 1 to 15 carbon atoms, it also being possible to replace one or more CH.sub.2 groups in these radicals, independently of one another, by --O--, --S--, ##STR2## --CO--, --CO--O--, --O--CO-- or --O--CO--O-- in such a way that oxygen atoms are not linked directly to one another,Z.sub.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 and A.sup.1 are each, independently of one another, trans-1,4-cyclohexylene in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by --O--, or are 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,m is 0, 1, 2 or 3,o and s are 0, 1 or 2, where (s+o) is >2.These liquid crystalline media find use in electro-optical display elements.
摘要:
Disclosed are trifluoromethylcyclohexane derivatives of the formula I ##STR1## whereinR is an alkyl or alkenyl radical having up to 18 C atoms which is unsubstituted or substituted by CN or by at least one halogen, and in which one or more non-adjacent CH.sub.2 groups may be replaced by a radical selected from the group comprising --O--, --S--, --CO--, --O--CO--, --CO--O-- and --C.tbd.C--,A.sup.1 and A.sup.2 are each, independently of one another,a) a 1,4-phenylene radical, in which one or two CH groups may be replaced by N,b) a 1,4-cyclohexylene radical, in which one or two non-adjacent CH.sub.2 groups may be replaced by --O-- or --S--,c) a 1,4-cyclohexenylene, piperidine-1,4-diyl, 1,4-bicyclo[2,2,2]-octylene or naphthalene-2,6-diyl radical,it being possible for the radicals a) and b) to be monosubstituted or polysubstituted by halogen atoms or cyano and/or methyl groups, ##STR2## Z.sup.1 and Z.sup.2 are each, independently of one another, --CO--O--, --O--CH--, --CH.sub.2 CH.sub.2 --, --CH(CN)--CH.sub.2 --, --CH.sub.2 --CH(CN)--, --CH.dbd.CH--, --OCH .sub.2 --, --CH.sub.2 O--, --CH.dbd.N--, --N.dbd.CH--, --NO.dbd.N--, --N.dbd.NO--, --N.dbd.N-- or a single bond, ando is 0, 1 or 2.These compounds can be used as components of liquid-crystalline media for electrooptical display elements, in particular for matrix liquid-crystal displays.
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:
Nitrogen-containing heterocyclic compounds of the formula IR.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --[Z.sup.2 --A.sup.3 ].sub.n --R.sup.2whereinR.sup.1 and R.sup.2 in each case independently of one another are an alkyl group with 1-15 C atoms, it also being possible for one or two non-adjacent CH.sub.2 groups to be replaced by O atoms and/or --CO-- groups and/or --O--CO-- groups and/or --CO--O-- groups, and one of the radicals R.sup.1 and R.sup.2 is also H, F, Cl, Br or CN,A.sup.1 is a 1,4-cyclohexylene group, it also being possible for one or two non-adjacent CH.sub.2 groups to be replaced by O atoms, a 1,4-bicyclo-(2,2,2)-octylene group or a 1,3-dithiane-2,5-diyl group,Z.sup.1 and Z.sup.2 in each case independently of one another are --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O-- or a single bond,A.sup.2 and A.sup.3 in each case independently of one another are a 1,4-phenylene group, pyrimidine-2,5-diyl group, 1,4-cyclohexylene group, it also being possible for one or two non-adjacent CH.sub.2 groups to be replaced by O atoms, 1,3-dithiane-2,5-diyl group or a 1,4-bicyclo(2,2,2)-octylene group andn is 0 or 1,with the provisos that(a) at least one of the groups A.sup.2 and A.sup.3 is a pyrimidine-2,5-diyl group,(b) at least one of the groups Z.sup.1 and Z.sup.2 is not a single bond if A.sup.2 is pyrimidine-2,5-diyl and R.sup.2 is alkyl or CN,(c) Z.sup.1 is not --CO--O-- if A.sup.3 is pyrimidine-2,5-diyl and A.sup.1 is 1,4-cyclohexylene,(d) n is not 0 if A.sup.1 is 1,4-cyclohexylene and Z.sup.1 is --CH.sub.2 CH.sub.2 --, and(e) Z.sup.1 is not --CH.sub.2 CH.sub.2 -- if R.sup.2 is CN, and(f) Z.sup.1 is --CH.sub.2 CH.sub.2 --, --OCH.sub.2 -- or --CH.sub.2 O--, if A.sup.1 is 1,4-cyclohexylene and --A.sup.2 --[Z.sup.2 --A.sup.3 ].sub.n -- is ##STR1## and acid addition salts thereof, can be used as components of liquid crystal phases.
摘要:
Nitrogen-containing heterocyclic compounds of the formula IR.sup.I --(A--Z).sub.n --A--R.sup.2 Iwherein R.sup.1 and R.sup.2 in each case independently of one another are alkyl group with 1-15 C atoms, wherein one or two non-adjacent CH.sub.2 groups can also be replaced by 0 atoms and/or --CO-- group and/or --O--CO-- groups and/or --CO--O-- groups, and one of the radicals R.sup.1 and R.sup.2 can also be H, CN, F, Cl or Br, the groups A in each case independently of one another are a 1,4-phenylene group, wherein one or two CH groups can also be replaced by N atoms, a 1,4-cyclohexylene group, wherein one or two CH.sub.2 groups which are not adjacent can be replaced by 0 atoms, a 1,3-dithiane-2,5-diyl group, a 1,4-bicyclo(2,2,2)-octylene group, a decahydronapthalene-2,6-diyl group or a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, the group Z in each case independently of one another are --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O-- or a single bond and n is 3 or 4, with the proviso that (a) at least one of the groups A is a "1,4" phenylene group, wherein two CH groups are replaced by N atoms, and (b) at least one of the other groups A contains a cycloaliphatic radical and/or at least one group Z is not a single bond,can be used as components of liquid crystal phases.
摘要:
Described are matrix liquid crystal displays having two plane parallel support plates which together with a frame form a cell, integrated non-linear elements for switching individual picture elements on the support plates and a nematic liquid crystal mixture which is present in the cell and has a positive dielectric anisotropy and high resistivity. The liquid crystal mixture has a nematic phase range of at least 60° C., a maximum viscosity at 20° C. of 30 mPa·s and a mean dielectricity constant ε≦8. The liquid crystal mixture contains: a) at least 10% by weight of a liquid-crystalline component B having one or more compounds of the following formulae: and b) up to 90% by weight of a liquid-crystalline component A having one or more compounds with a dielectric anisotropy of −1.5 to 1.5 of the formula I:
摘要:
The invention relates to a matrix liquid crystal display containing integrated non-linear elements and a liquid crystal mixture which has a particularly high resistivity.
摘要:
Supertwist liquid crystal displays having very short switching times are obtained if the nematic liquid crystal mixture contains at least one component chosen from group A consisting of compounds of the formulae AI to AVI: wherein R1 and R2 in each case independently of one another are each R and R is alkyl having 1-12 C atoms, wherein one or two non-adjacent CH2 groups can also be replaced by —O—, —CH═CH—, —CO—, —O—CO— or —CO—O—, and up to four other components.
摘要:
Anisotropic compounds of the formula (1) specified in claim 1 are suitable, owing to their low .DELTA..epsilon./.epsilon..perp. values for liquid crystal displays which have high information densities of for examples up to 10.sup.6 image dots and accordingly need to be highly multiplexible; compared with known compounds they offer improved application properties and are relatively simple to synthesize.