Liquid crystal composition and liquid crystal display device

A liquid crystal composition having a dielectric anisotropy (25° C.) at a frequency of 1 kHz is −2 or less and containing at least one compound selected from the group of compounds represented by formula (1) as a first component further containing at least one compound selected from the group of compounds represented by formula (2) as a second component:

• wherein R1, R2, R3, R4, R5 and R6 are independently hydrogen, halogen, hydroxy, —CH2OH, —SF5, —NO2, P—Sp- or alkyl having 1 to 30 carbons, the alkyl is straight-chain, branched-chain or cyclic, the alkyl may have an unsaturated bond, and in the alkyl, at least one of non-adjacent —CH2— may be replaced by —O—, —S—, —CO—, —CO—O— or —O—CO—, and in the groups, at least one of hydrogen may be replaced by halogen;
• P is a polymerizable group;
• Sp is a single bond or alkylene having 1 to 20 carbons, and in the alkylene, at least one of hydrogen may be replaced by halogen or —C≡N, and in the groups, at least one of non-adjacent —CH2— may be independently replaced by —O—, —S—, —NH—, —NR7—, —SiR7R8—, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S—, —NR7—CO—O—, —O—CO—NR7—, —NR7—CO—NR8—, —CH═CH— or —C≡C—;
• at least one of R1, R2, R3, R4, R5 and R6 is P—Sp-;
• Z1, Z2, Z3, Z4, Z5 and Z6 are independently a single bond, —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— or alkylene having 1 to 12 carbons;
• Z7 is independently —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —OCH2—, —CH2O—, —SCH2—, —CH2S—, —CF2O—, —OCF2—, —CF2S—, —SCF2—, —(CR7R8)m—, —(CR7═CR8)m, —C≡C—, —CR7═CR8—CO—O—, —O—CO—CR7═CR8—, —CO—NR7—, —NR7—CO—, —CO—S—, —S—CO—, —O—CO—CR7—CR8—O—, —O—CR7—CR8—CO—O—, —CR7═CR8—CO—, —CO—CR7═CR8—, —C(═CR7R8)—, —O—CO—CR7R8—CR9R10—O—, —O—CR7R8—CR9R10—CO—O— or a single bond;
• R7, R8, R9 and R10 are independently hydrogen, halogen or alkyl having 1 to 12 carbons, the alkyl is straight-chain, branched-chain or cyclic, the alkyl may have an unsaturated bond, and in the alkyl, at least one of non-adjacent —CH2— may be replaced by —O—, —S—, —CO—, —CO—O—, or —O—CO—, and in the groups, at least one of hydrogen may be replaced by halogen;
• m is 1, 2, 3 or 4;
• and n is an integer from 1 to 12;
• R11 and R12 are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine;
• ring A and ring C are independently 1,4-cyclohexylene, 1,4-phenylene, 1,4-phenylene in which at least one of hydrogen is replaced by fluorine or chlorine, or tetrahydropyran-2,5-diyl;
• ring B is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl;
• Z8 and Z9 are independently a single bond, ethylene, methyleneoxy or carbonyloxy;
• p is 1, 2 or 3;
• r is 0 or 1;
• and a sum of p and r is 3 or less;
• wherein when the composition is used in an active matrix (AM) device, it has a response time ranging from 4.0 to 5.9 ms.