Patent ID: 8273264

Claim:
A compound of formula I in which R 1 denotes H, F, Cl, Br, —CN, —SCN, —NCS, SF 5 or straight-chain or branched alkyl having 1 to 12 C atoms, in which, in addition, one or more non-adjacent CH 2 groups may each be replaced, independently of one another, by —C≡C—, —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 or Br, or P-Sp-, R 2 denotes H or an unsubstituted alkyl having 1 to 5 C atoms, P denotes a polymerizable group, Sp denotes a spacer group or a single bond, A 1 on each occurrence, identically or differently, denotes phenylene-1,4-diyl, in which, in addition, one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH 3 , CHF 2 , CH 2 F, OCH 3 , OCHF 2 or OCF 3 , cyclohexane-1,4-diyl, in which, in addition, one or two non-adjacent CH 2 groups may be replaced, independently of one another, by O and/or S, and one or more H atoms may be replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl, Z 1 and Z 2 each, independently of one another, denote —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —C 2 H 4 —, —C 2 F 4 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —CFHCFH—, —CFHCH 2 —, —CH 2 CFH—, —CF 2 CFH—, —CFHCF 2 —, —CH═CH—, —CF═CH—, —CH═CF—, —CF═CF—, —C≡C— or a single bond, and m denotes 0, 1, 2 or 3.