Liquid-crystal medium

A process of preparing an LC medium, comprising the steps of:

• mixing one or more polymerizable compounds selected from formula M13:
• in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning:
• P1, P2 an acrylate or methacrylate group,
• Sp1, Sp2 a single bond,
• L F, Cl, CN or straight-chain, optionally mono- or polyfluorinated alkyl or alkoxy having 1 to 12 C atoms, straight-chain, optionally mono- or polyfluorinated alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy, or alkoxycarbonyloxy having 2 to 12 C atoms, or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 3 to 12 C atoms, and
• r 0, 1, 2, 3 or 4,
• with one or more compounds of formula IIB2
• in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and at least two compounds of formula IA, one or more compounds of formula IB, and at least one compound of formula IC-1 and/or IC-2
• in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning:
• R1, R2 straight chain alkyl having 1 to 25 C atoms or branched or cyclic alkyl having 3 to 25 C atoms, wherein one or more non-adjacent CH2-groups are optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, CR0═CR00—, —C≡C—,
• in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F or Cl,
• R0, R00 H or alkyl having 1 to 12 C atoms,
• L1, L2 F,
• alkyl an alkyl radical having 1 to 7 C atoms, and
• alkenyl an alkenyl radical having 2 to 5 C atoms,
• wherein the proportion of compounds of formula IA of the LC medium is >8% by weight based on the total weight of compounds of formulae IA, IB, and IC present, and wherein the total proportion of compounds of formulae IC-1 and/or IC-2 in the LC medium is from 20 to 45% by weight, and
• one or more compounds of formula III2-2:
• in which
• L11 and L 12 each, independently of one another, denote F, Cl, CF3 or CHF2,
• (O) denotes O or a single bond,
• RIIIA denotes an alkyl having 1-7 C atoms, an alkenyl having 2-7 C atoms or a group Cy-CmH2m+1—,
• m and n are, identically or differently, 0, 1, 2, 3, 4, 5 or 6, and
• Cy denotes a cycloaliphatic group having 3, 4 or 5 ring atoms, wherein the cycloaliphatic group is optionally substituted with an alkyl having 1-3 carbon atoms, an alkenyl having 2-3 C atoms or with halogen or CN,
• and optionally with one or more compounds of formula II, III, IV and/or V
• wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings
• R1 and R2 straight chain alkyl having 1 to 25 C atoms or branched or cyclic alkyl having 3 to 25 C atoms, wherein one or more non-adjacent CH2-groups are optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, CR0═CR00—, —C≡C—,
• in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F or Cl, H or alkyl having 1 to 12 C atoms,
• R0, R00 H or alkyl having 1 to 12 C atoms,
• A1 and A2 a group selected from the following formulae
• Z1 and Z2—CH2CH2—, —CH═CH—, —CF2O—, —OCF2—, —CH2O—, —OCH2—, —CO—O—, —O—CO—, —C2F4—, —CF═CF—, —CH═CH—CH2O— or a single bond,
• L1, L2, L3 and L4 F, Cl, OCF3, CF3, CH3, CH2F or CHF2,
• Y H, F, Cl, CF3, CHF2 or CH3,
• LC CH3 or OCH3,
• a1 1 or 2, and
• a2 0 or 1,
• in which
• R11 and R 12 each, independently of one another, denote H, an alkyl or alkoxy radical having 1 to 15 C atoms, where one or more CH2 groups in these radicals may each be replaced, independently of one another, by
• —C≡C—, —CF2O—, —OCF2—, —CH═CH—, by —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen,
• A3 on each occurrence, independently of one another, denotes
• a) 1,4-cyclohexenylene or 1,4-cyclohexylene radical, in which one or two non-adjacent CH2 groups may be replaced by —O— or —S—,
• b) a 1,4-phenylene radical, in which one or two CH groups may be replaced by N, or
• c) a radical selected from the group consisting of spiro[3.3]heptane-2,6-diyl, 1,4-bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl and fluorene-2,7-diyl, wherein the radicals a), b) and c) may be mono- or polysubstituted by halogen atoms, denotes 0, 1 or 2,
• n denotes 0, 1 or 2,
• Z1 on each occurrence independently of one another denotes-CO—O—, —O—CO—, —CF2O—, —OCF2—, —CH2O—, —OCH2—, —CH2—, —CH2CH2—, —(CH2)4—, —CH═CH—CH2O—, —C2F4—, —CH2CF2—, —CF2CH2—, —CF═CF—, —CH═CF—, —CF═CH—, —CH═CH—, —C≡C— or a single bond, and
• L11 and L12 each, independently of one another, denote F, Cl, CF3 or CHF2, and
• W denotes O or S, and if n is 0 then Wis not S, wherein the one or more compounds of formula III2-2 are excluded from the one or more compounds of formula III,
• in which
• R41 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkenyl radical having 2 to 7 C atoms, and
• R42 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms, an unsubstituted alkenyl radical having 2 to 7 C atoms,
• in which
• R51 and R52 independently of one another, have one of the meanings given for R41 and R42,
• identically or differently, denote
• Z51, Z52 each, independently of one another, denote —CH2—CH2—, —CH2—O—, —CH═CH—, —C≡C—, —COO— or a single bond, and
• n is 1 or 2,
• optionally with further liquid-crystalline compounds and/or additives, and optionally polymerizing the polymerizable compounds.