Polymerisable liquid crystal material

Polymerisable LC material comprising the following components:

• A) at least one compound having a high birefringence selected of formula I
• wherein
• P is a polymerisable or reactive group,
• Sp is a spacer group or a single bond,
• A is in case of multiple occurrence independently of one another an aromatic or aliphatic 5- or 6-ring, or a group comprising two or three fused aromatic or aliphatic 5- or 6-rings, these rings optionally containing one or more hetero atoms selected from N, O and S, and optionally being substituted by one or more identical or different groups L1,
• Z is in case of multiple occurrence independently of one another —O—, —S—, —CO—, —COO—, —OCO—, —S—CO—, —CO—S—, —O—CO—O—, —CO—NR0—, —NR0—CO—, —OCH2—, —CH2O—, —SCH2—, —CH2S—, —CF2O—, —OCF2—, —CF2S—, —SCF2—, —CH2CH2—, —CF2CH2—, —CH2CF2—, —CF2CF2—, —CH═CR0—, —CH═CH—, —CH═CF—, —CY1═CY1—, —C≡C—, —CH═CH—COO—, —OCO—CH═CH— or a single bond,
• R0, R00 are independently of each other H or alkyl with 1 to 12 C-atoms,
• Y1, Y2 are independently of each other H, F, Cl or CN,
• m1, m2 are independently of each other 0, 1 or 2, with m1+m2 ≦3,
• L1, L2 are independently of each other F, Cl, Br, I, CN, NO2, P-Sp- or alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonlyoxy or alkoxycarbonyloxy with 1 to 12 C atoms, wherein one or more H atoms are optionally replaced by F or Cl,
• r1, r2 are independently of each other 0, 1, 2, 3 or 4,
• R1 is H, halogen, CN, NO2, NCS, SF5, P-Sp- or straight chain or branched alkyl with 1 to 20 C-atoms that is optionally mono- or polysubstituted by F, Cl, Br, I or CN, and wherein one or more non-adjacent CH2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NR0—, —SiR0R00—, —CO—, —COO—, —OCO—, —OCO—O—, —NR0—CO—, —CO—NR0—, —NR0—CO—NR0—, —S—CO—, —CO—S—, —CY1═CY2— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another,
• wherein at least one compound of formula Ia
• wherein P and Sp are as defined in formula I,
• Z0 is —COO—, —OCO— or a single bond,
• L1a,1b,2a,2b are independently of each other F, Cl, CN, (O)aCbFcH2b+1−c or COCH3,
• r1a, r1b, r2a, r2b are independently of each other 0 or 1, with at least one of r1a,
• r1b, r2a, r2b being 1,
• R1a is Cl or optionally mono- or polyfluorinated straight-chain or branched alkyl with 1 to 6 C-atoms wherein one or two non-adjacent CH2-groups are optionally replaced by —O—, —S—, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO— or —CO—S— in such a manner that O and/or S atoms are not linked directly to one another,
• a is 0 or 1,
• b is 1 or 2,
• c is 0, 1, 2, 3, 4 or 5,
• B) at least one polymerisable mesogenic compound having two or more polymerisable groups,
• C) at least one chiral compound having a high helical twisting power (HTP),
• D) optionally at least one monoreactive polymerisable compound having an enantiotropic nematic phase and a clearing point of 75° C. or higher,
• E) at least one dichroic photoinitiator.