| 主权项 |
1. A liquid-crystal medium comprising:
one or more compounds selected from formulae I, II and III in which R1 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, n denotes 0 or 1, and independently of one another, denote alternatively denotesin which
R2 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, Z21 denotes trans-CH═CH—, trans-CF═CF— or —C≡C—, and and independently of one another, denote in which R3 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, one of Z31 and Z32 denotes trans-CH═CH—, trans-CF═CF— or —C≡C— and the other one, independently thereof, denotes trans-CH═CH—, trans-CF═CF— or a single bond, and independently of one another, denote alternatively independently denotes e and
optionally one or more polymerizable compounds preferably of formula P
Pa-(Spa)s1-(A1-Z1)n1-A2-Q-A3-(Z4-A4)n2-(Spb)s2—Pb P wherein the individual radicals have the following meanings: Pa, Pb each, independently of one another, are a polymerizable group, Spa, Spb each, independently of one another, denotes a spacer group, s1, s2 each, independently of one another, denotes 0 or 1, n1, n2 each, independently of one another, denotes 0 or 1, Q denotes a single bond, —CF2O—, —OCF2—, —CH2O—, —OCH2—, —(CO)O—, —O(CO)—, —(CH2)4—, —CH2—CH2—, —CF2—CF2—, —CF2—CH2—, —CH2—CF2—, —CH═CH—, —CF═CF—, —CF═CH—, —(CH2)3O—, —O(CH2)3—, —CH═CF—, —C≡C—, —O—, —CH2—, —(CH2)3—, or —CF2—, Z1, Z4 each denotes a single bond, —CF2O—, —OCF2—, —CH2O—, —OCH2—, —(CO)O—, —O(CO)—, —(CH2)4—, —CH2—CH2—, —CF2—CF2—, —CF2—CH2—, —CH2—CF2—, —CH═CH—, —CF═CF—, —CF═CH—, —(CH2)3O—, —O(CH2)3—, —CH═CF—, —C≡C—, —O—, —CH2—, —(CH2)3—, or —CF2—, where Z1 and Q or Z4 and Q do not simultaneously denote a group selected from —CF2O and —OCF2—, A1, A2, A3, A4 each, independently of one another, denotes a diradical group selected from the following groups:a) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene and 1,4′-bicyclohexylene, in which, in addition, one or more non-adjacent CH2 groups may each be replaced by —O— and/or —S— and in which, in addition, one or more H atoms may each be replaced by F,b) the group consisting of 1,4-phenylene and 1,3-phenylene, in which, in addition, one or two CH groups may each be replaced by N and in which, in addition, one or more H atoms may each be replaced by L,c) the group consisting of tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobutane-1,3-diyl, piperidine-1,4-diyl, thiophene-2,5-diyl and selenophene-2,5-diyl, each of which may also be mono- or polysubstituted by L,d) the group consisting of saturated, partially unsaturated or fully unsaturated, and optionally substituted, polycyclic radicals having 5 to 20 cyclic C atoms, one or more of which may, in addition, be replaced by heteroatoms, preferably selected from the group consisting of bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, where, in addition, one or more H atoms in these radicals may be replaced by L, and/or one or more double bonds may be replaced by single bonds, and/or one or more CH groups may be replaced by N,
and A3, alternatively may be a single bond, L on each occurrence, identically or differently, denotes F, Cl, CN, SCN, SF5 or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, R03, R04 each, independently of one another, denote H, F or straight-chain or branched alkyl having 1 to 12 C atoms, in which, in addition, one or more H atoms may each be replaced by F, M denotes —O—, —S—, —CH2—, —CHY1— or —CY1Y2—, and Y1 and Y2 each, independently of one another, have one of the meanings indicated above for R03, or denote Cl or CN, and one of the groups Y1 and Y2 alternatively denotes —OCF3, preferably H, F, Cl, CN or CF3. |
