Liquid crystal mixture and light modulating device using the same

A liquid crystal mixture applied in light modulating devices, comprising:

• at least one compound selected from the group of compounds of formula I
• R1-MG1-X-MG2-R2 I;
• at least one compound selected from the group of compounds of formula II and/or formula III
• and at least one chiral compound,
• wherein
• R1 and R2 each independently denote —H, —F, —Cl, —CN, —NCS or a chain alkyl group with 1 to 25 C atoms where one or more H atom may be independently substituted by halogen or CN and one or more nonadjacent —CH2— may be independently replaced by —O—, —S—, —NH—, —N(CH3)—, —CO—, —COO—, —OCO—, —OCOO—, —SCO—, —COS—, —CH═CH—, —CH═CF—, —CF═CF— or —C≡C— in such a manner that two —O— are not directly adjacent to one another,
• MG1 and MG2 each independently denote a mesogenic group,
• X is a straight-chain or branched alkyl group with 1, 3 or 5-40 C atoms where one or more nonadjacent —CH2— may be independently replaced by —O—, —S—, —NH—, —N(CH3)—, —CO—, —COO—, —OCO—, —OCOO—, —SCO—, —COS—, —CH═CH—, —CH═CF—, —CF═CF—, —C≡C— or —CH(CN)— in such a manner that no two —O— are adjacent to one another or no two groups selected from —OCO—, —SCO—, —OCOO—, —COS—, —COO— and —CH═CH— are adjacent to each other,
• H1, H2, H3, H4 and H5 each independently denote a ring structure selected from the group of
• where one or more H atoms may be independently substituted by halogen, a alkyl group with 1-10 C atoms or a ester group,
• B1 and B2 each independently denote —COO—, —OCO—, —CF2O—, —OCF2—, —CH2O—, —OCH2—, —C≡C—, —CH═CH—, —CF2CF2—, —CF═CF—, a single bond or —(CH2)a— where a is a even number between 2-10,
• A1, A2, A3 and A4 each independently denote —CN, —F, —Cl, —NCS, —OCF3, —CF3 or a chain alkyl group with 1-25 C atoms where one or more nonadjacent —CH2— may be independently replaced by —O—, —S—, —NH—, —N(CH3)—, —CO—, —COO—, —OCO—, —OCOO—, —SCO—, —COS—, —CH═CH—, —CH═CF—, —CF═CF— or —C≡C—,
• k is 1, 2, 3 or 4, m is 0, 1 or 2, n is 1, 2 or 3, o is 1 or 2, and m+n+o is no more than 5, and the compound of formula I is 1%-34% by weight of the liquid crystal mixture.