Dichroic dye composition

A composition comprising

• one or more compounds of formula I
• and one or more compounds of formula II
• wherein
• R1 on each occurrence, identically or differently, denotes H, F, CN, N(Rz)2, Si(Rz)3, or a straight-chain or branched alkyl or alkoxy having 1 to 20 C atoms, in which, in addition, one or more non-adjacent CH2 groups may each be replaced, independently of one another, by —C(Rz)═C(Rz)—, —C≡C—,
• —N(Rz)—, —O—, —S—, —CO—, —CO—O—, —O—CO— or —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 or CN,
• X on each occurrence, identically or differently, denotes CRa or N,
• Ra on each occurrence, identically or differently, denotes straight-chain or branched alkyl having 1 to 12 C atoms, F, Cl, N(Rz)2 or CN,
• R2 and Rz on each occurrence, identically or differently, denote H, halogen, straight-chain, branched or cyclic alkyl having 1 to 12 C atoms, in which, in addition, one or more non-adjacent CH2 groups may be replaced by —O—, —S—, —CO—, —CO—O—, —O—CO— or —O—CO—C— 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 or Cl,
• Ar1 and Ar2 on each occurrence, identically or differently, denote an aryl or heteroaryl group, which may be substituted by one or more radicals L,
• L on each occurrence, identically or differently, denotes F, CO, CN, OH, SCN, SF5, N(Rz)2 or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms,
• Z1 on each occurrence, identically or differently, denotes a single bond, —O—, —S—, —C(O)—, —CRy1Ry2—, —CF2O—, —OCF2—, —C(O)—O—, —O—C(O)—, —OCH2—, —CH2O—, —CRx1═CRx2—, —C≡C—, —CRx1═CRx2—CO—, —CO—CRx1═CRx2—, —CRx1═CRx2—COO—, —OCO—CRx1═CRx2— or —N═N—,
• Z2 on each occurrence, identically or differently, denotes a single bond, —CF2O—, —OCF2— or —C≡C—,
• a, b, c and d independently of one another, denote 0 or 1,
• Rx1, Rx2 independently of one another, denote H, F, Cl, CN or alkyl having 1 to 12 C atoms,
• Ry1 denotes H or alkyl having 1 to 12 C atoms, and
• Ry2 denotes alkyl having 1 to 12 C atoms.