Polymerisable oligomeric liquid crystal, polymerisable medium and polymerised liquid crystal film

A polymerisable liquid crystal medium comprising one or more mono-, di- or multireactive liquid crystal or mesogenic compounds and one or more polymerisable, oligomeric liquid crystal or mesogenic compounds, wherein the at least one polymerisable oligomeric liquid crystal or mesogenic compound comprises one or more compounds of formula O:

• P1-Sp1-[MG1-X1-E-X2]n-MG1-Sp2-P2 O
• wherein
• P1 and P2 independently of each other denote a polymerisable group,
• Sp1 and Sp2 independently of each other are a spacer group or a single bond,
• X1 and X2 independently of each other denote —S—, —O— or NRx,
• E is alkylene having 2 to 20 C atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN and in which, in addition, one or more non-adjacent CH2 groups may each be replaced, independently of one another, by —O—, —S—, —NH—, —NRx—, —SiRxRy—, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S—, —NRx—CO—O—, —O—CO—NRx—, —NRx—CO—NRy—, —CH═CH—or —C═C— in such a way that O and/or S atoms are not linked directly to one another,
• MG1 is a rod-shaped mesogenic group, which is selected of formula M
• -(A1-Z1)a-A2- M
• wherein
• A1 and A2 denote, in case of multiple occurrence independently of one another, an aromatic or alicyclic group, which optionally contains one or more heteroatoms selected from N, O and S, and is optionally mono- or polysubstituted by L,
• L is P-Sp-, F, Cl, Br, I, —CN, —NO2, —NCO, —NCS, —OCN, —SCN, —C(═O)NRxRy, —C(═O)ORx, —C(═O)Rx, —NRxRy, —OH, —SF5, optionally substituted silyl, aryl or heteroaryl with 1 to 12 C atoms, and straight chain alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy with 1 to 12 C atoms or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy with 3 to 12 C atoms, wherein one or more H atoms are optionally replaced by F or Cl,
• Rx and Ry independently of each other denote H or alkyl with 1 to 12 C-atoms,
• Z1 denotes, in case of multiple occurrence independently of one another, —O—, —S—, —CO—, —COO—, —OCO—, —S—CO—, —CO—S—, —O—COO—, —CO—NRx—, —NRx—CO—, —NRx—CO—NRY, —NRx—CO—O—, —O—CO—NRx—, —OCH2—, —CH2O—, —SCH2—, —CH2S—, —CF2O—, —OCF2—, —CF2S—, —SCF2—, —CH2CH2—, —(CH2)n1, —CF2CH2—, —CH2CF2—, —CF2CF2—, —CH═N—, —N═CH—, —N═N—, —CH═CRx—, —CY1=CY2—, —C═C—, —CH═CH—COO—, —OCO—CH═CH—or a single bond,
• Y1 and Y2 independently of each other denote H, F, Cl or CN,
• a is 1, 2, 3 or 4,
• n1 is an integer from 1 to 10,
• n is the average number of repeat units per molecule of compound of formula O and is from 1 to 10.