| 主权项 |
1. A liquid crystal medium comprising:
a polymerizable component A) comprising one or more polymerizable compounds; and a liquid-crystalline component B) comprising one or more low-molecular-weight compounds; wherein component A) comprises one or more polymerizable compounds of formula I
P-(Sp)s1-A1-Z1-A2(-Z2-A3)m-(Sp)s2-P Iwherein:
P on each occurrence, identically or differently, denotes a polymerizable group, Sp on each occurrence, identically or differently, denotes a spacer group, s1, s2 each, independently of one another, denote 0 or 1, wherein one of s1 and s2 is 0 and the other is 1, A1, A2, A3 each, independently of one another, denote a 1,4-phenylene, naphthalene-1,4-diyl or naphthalene-2,6-diyl group, where, in addition, one or more CH groups in these groups may be replaced by N, phenanthrene-2,7-diyl, anthracene-2,7-diyl, 9,10-dihydrophenanthrene-2,7-diyl, 9H-fluorene-2,7-diyl, 9,9-dimethylfluorene-2,7-diyl or dibenzofuran-3,7-diyl, and where each of these groups may be unsubstituted or mono- or polysubstituted by L, m denotes 0, 1 or 2, L on each occurrence, identically or differently, denotes P—, P-Sp-, OH, CH2OH, halogen, —CN, —NO2, —NCO, —NCS, —OCN, —SCN, —C(═O)N(Rx)2, —C(═O)Y1, —C(═O)Rx, —N(Rx)2, optionally substituted silyl or an optionally substituted carbon group or hydrocarbon group, Rx denotes P—, P-Sp-, H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH2 groups may be replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in such a way that O and/or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, Cl, P— or P-Sp-, Y1 denotes halogen, Z1, Z2 each, independently of one another, denote —CO—O—, —OCO—, —CY═CY—, —C≡C— or a single bond, where at least one of the radicals Z1 and Z2 denotes —C≡C—, and Y on each occurrence, identically or differently, denotes H or F; and wherein component B) comprises one or more compounds selected from formulae CY and PY:wherein:
a denotes 1 or 2, b denotes 0 or 1, R1 and R2 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH2 groups may be replaced by —O—, —CH═CH—, —CO—, —O—CO— or —CO—O— in such a way that O atoms are not linked directly to one another, Zx denotes —CH═CH—, —CH2O—, —OCH2—, —CF2O—, —OCF2—, —O—, —CH2—, —CH2CH2— or a single bond, and L1-4 each, independently of one another, denote F, Cl, OCF3, CF3, CH3, CH2F, or CHF2; and wherein the proportion of polymerizable compounds of formula I in said medium is 0.05 to 5%. |
