摘要:
The invention relates to a ferroelectric liquid-crystalline medium having improved low-temperature behavior, pronounced bistability and a phase sequence containing the phases isotropic, cholesteric, smectic A and chiral smectic C, comprising an achiral base material having a broad smectic C phase and at least one chiral dope which induces a spontaneous polarization of from 5 to 40 nCcm.sup.-2 in the achiral base material, characterized in that the medium has a chiral smectic C phase which is stable at least to -30.degree. C., and to the use thereof in electro-optical devices.
摘要:
Novel 2,5-disubstituted heterocyclic compounds of the formula I ##STR1## in which n is 1 to 10,Het is ##STR2## Ring A is trans-1,4-cyclohexylene or, in the case where Het= ##STR3## X=--OCF.sub.3 or --OCHF.sub.2 and/or Y=Z=F, is alternatively 1,4-phenylene,X is CN, F, Cl, --CF.sub.3, --OCF.sub.3 or --OCHF.sub.2, andY and Z are each, independently of one another, H or F, can be used as components of liquid-crystalline media.
摘要翻译:新的2,5-二取代杂环化合物,其中n为1至10,Het为环A为反式-1,4-亚环己基,或在Het = X = -OCF 3或-OCHF 2和/或Y = Z = F,或者1,4-亚苯基,X是CN,F,Cl,-CF 3,-OCF 3或-OCHF 2,Y和Z各自 彼此独立地可以使用H或F作为液晶介质的组分。
摘要:
1,4-disubstituted 2,6-difluorobenzene compound of formula I wherein R is an alkyl or alkenyl radical, A1 and A2, in each case independently of one another, are (a) a trans-1,4-cyclohexylene radical in which a CH2 group may be replaced by —O— and/or —S, (b) a 1,4-phenylene radical in which a CH group may be replaced by N, (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, Z1 and Z2 are —CO—O—, —O—CO—, —CH2—O—, —OCH2—, —CH2CH2—, —CH═CH—, —C≡C— or a single bond m and n are 0, 1, 2 or 3, (m+n) is 1, 2 or 3, X is R or F, Cl, CF3, —OCF3, or —OCHF2, —OCF5, —CN or —NCS with the proviso that at least one of the radicals A1 and A2 present in the molecule is are suitable as components of liquid-crystalline media.
摘要:
Biphenylylethanes of the formula I ##STR1## in which one of the radicals R.sup.1 and R.sup.2 is X and the other radical R.sup.1 or R.sup.2 is R--Y-- whereX is H, halogen, --CF.sub.3, --OCHF.sub.2, --OCF.sub.3, --CN, --NCS or --NO.sub.2,R is alkyl, fluoroalkyl, alkenyl or oxaalkyl andY is O, S, --CO--O--, --O--CO--, --O--CO--O--, a single bond or--in the case where m=1--alternatively trans-1,4-cyclohexylene or ##STR2## m is 1 or 2, Ph is in each case identical or different radicals selected from the group comprising 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene and 3,5-difluoro-1,4-phenylene,L.sup.3 and L.sup.4 are each H, or one of these radicals is alternatively F,L.sup.1, L.sup.2and L.sup.5 are each H or F, with the proviso that in the case where X=CN or R.sup.1 =--NCS, Y is trans-1,4-cyclohexylene or ##STR3## and/or m=2 and/or one of the radicals L.sup.1, L.sup.2 and L.sup.3 is fluorine and/or Ph--CN is 2-fluoro-4-cyanophenyl or 3,5-difluoro-4-cyanophenyl,are suitable as components of liquid-crystalline phases.
摘要:
1,4-disubstituted 2,6-difluorobenzene compound of formula I wherein R is an alkyl or alkenyl radical, A1 and A2 are independently (a) a trans-1,4-cyclohexylene radical in which a CH2 group may be replaced by -O- and/or -S, (b) a 1,4-phenylene radical in which a CH group may be replaced by N, (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, Z1 and Z2 are —CO—O—, —O—CO—, —CH2O—,—OCH2—, —CH2CH2—, —CH═CH—,—C≡C—or a single bond m and n are 0, 1, 2 or 3, (m+n) is 1, 2 or 3, X is R or F, Cl, CF3, —OCF3, or —OCHF2, —OCF5, —CN or —NCS with the provisos that at least one of the radicals A1 and A2 present in the molecule is and at least one of Z1 or Z2 is —COO—, are suitable as components of liquid-crystalline media.
摘要:
Benzene derivatives of the formula I ##STR1## in which n is 1 to 7, Q is --CO or --(CH.sub.2).sub.r --, where r is 1 to 5, s is 0, 1 or 2, t is 0 or 1, where s+t.gtoreq.1, X is F, Cl, --CF.sub.3, --CN, --OCF.sub.3 or --OCHF.sub.2, and Y, L and Z are each, independently of one another, H or F.
摘要:
The invention relates to dihalogenobenzene derivatives 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.2wherein R.sup.1, R.sup.2, A.sup.1, A.sup.2, A.sup.3, Z.sup.1, Z.sup.2 and n are as defined in the specification.
摘要:
The invention relates to an electrooptical liquid crystal systemwhich contains a dielectrically positive liquid crystal mixture and a further optically transparent medium between 2 electrodes which are optionally applied to substrate sheets,whose liquid crystal molecules in the switched-off state have an irregular orientation,in which one of the refractive indices of the liquid crystal mixture essentially agrees with the refractive index of the matrix n.sub.M and/or in which the quotient of the mass of the liquid crystal mixture and of the mass of the optically transparent medium is 1.5 or more and,which, independently of the polarization of the incident light, has a reduced transmission in one of the two switch states compared to the other state andwhose liquid crystal mixture contains one or more compounds of the formula I ##STR1## in which Q.sup.1 is ##STR2## are independently of one another trans-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-l,4-phenylene, 3-fluoro-1,4-phenylene and one of A.sup.1 and, if present, A.sup.2, is also pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl or naphthalene-2,6-diyl,Z.sup.1 and Z.sup.2 are independently of one another a single bond, --CH.sub.2 CH.sub.2 --, --COO--, --OCO--, --C--C--, --CH.sub.2 O-- or any desired combinations of these bridge groups,Y and X are independently of one another H or F, and one of X and Y is also Cl,W is --CN, --Cl, --F, --CF.sub.3, --OCF.sub.3, --OCHF.sub.2, --NCS or R.sup.2R.sup.1 and R.sup.2 independently of one another are alkyl having 1-12 C atoms, in which one or 2 non-adjacent CH.sub.2 groups can also be replaced by --O-- or --HC.dbd.CH--, andm is 0, 1 or 2.
摘要:
4-Q.sup.1 -4'-Q.sup.2 -2,3-Difluorobiphenyls whereinQ.sup.1 and Q.sup.2 independently of one another are each R or R-A.sup.1 -A.sup.2 -Z in whichR (sic) alkyl having 1-15 C atoms or alkenyl having 3-15 C atoms each of which is unsubstituted or monosubstituted by cyano or at least monosubstituted by fluorine or chlorine, and in which in each case one or two non-adjacent CH.sub.2 groups can also be replaced by --O--, --CO--, --O--CO, --CO--O-- or --O--COO--, (sic) --COO--, --O--CO--, --CH.sub.2 O, --O--CH.sub.2 --, --CH.sub.2 CH.sub.2 -- or a single bond, andA.sup.1 and A.sup.2 independently of one another . . (sic) each 1,4-phenylene which is unsubstituted or substituted by one or two fluorine atoms, and in which one or two CH groups can also be replaced by N, or trans-1,4-cyclohexylene wherein one or two non-adjacent CH.sub.2 groups can also be replaced by --O--, and one of the two groups A.sup.1 and A.sup.2 can also be a single bond,subject to the proviso that Z is --CO--O, --O--CO--, --CH.sub.2 O--, --OCH.sub.2 -- or --CH.sub.2 CH.sub.2 --, if one of the groups Q.sup.1 or Q.sup.2 is alkyl or alkoxy and the other group Q.sup.1 or Q.sup.2 is R-A.sup.1 -A.sup.2 -Z wherein one of the two groups A.sup.1 and A.sup.2 is a single bond, are suitable for use as components of liquid-crystal media.
摘要:
The invention relates to an electrooptical liquid crystal systemwhich contains a dielectrically positive liquid crystal mixture and a further optically transparent medium between 2 electrodes which are optionally applied to substrate sheets,whose liquid crystal molecules in the switched-off state have an irregular orientation,in which one of the refractive indices of the liquid crystal mixture essentially agrees with the refractive index of the matrix n.sub.M and/or in which the quotient of the mass of the liquid crystal mixture and of the mass of the optically transparent medium is 1.5 or more and,which, independently of the polarization of the incident light, has a reduced transmission in one of the two switch states compared to the other state andwhose liquid crystal mixture contains one or more compounds of the formula I ##STR1## in which Q.sup.1 is ##STR2## are independently of one another trans-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene and one of A.sup.1 and, if present, A.sup.2, is also pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl or naphthalene-2,6-diyl,Z.sup.1 and Z.sup.2 are independently of one another a single bond, --CH.sub.2 CH.sub.2 --, --COO--, --OCO--, --C.tbd.C--, --CH.sub.2 O-- or any desired combinations of these bridge groups,Y and X are independently of one another H or F, and one of X and Y is also Cl,W is --CN, --Cl, --F, --CF.sub.3, --OCF.sub.3, --OCHF.sub.2, --NCS or R.sup.2R.sup.1 and R.sup.2 independently of one another are alkyl having 1-12 C atoms, in which one or 2 non-adjacent CH.sub.2 groups can also be replaced by --O-- or --HC.dbd.CH--, andm is 0, 1 or 2.