Fluorine-substituted-4-alkenylbenzoic acid and derivatives thereof, and nematic liquid crystal composition containing cyanophenyl benzoate derivatives and liquid crystal display system using the same

A nematic liquid crystal composition, comprising:

• a liquid crystal component A composed of 1, 2 or 3 or more groups selected from groups A1 to A6, wherein said groups are composed of compounds represented by the general formulae (I-1) to (I-18):
• 20 Group A1 (I-1) 364 (I-2) 365 (I-3) 366 Group A2 (I-4) 367 (I-5) 368 (I-6) 369 Group A3 (I-7) 370 (I-8) 371 (I-9) 372 Group A4 (I-10) 373 (I-11) 374 (I-12) 375 Group A5 (I-13) 376 (I-14) 377 (I-15) 378 Group A6 (I-16) 379 (I-17) 380 (I-18) 381
• wherein R11 each independently represents an alkyl or alkoxy group having 1 to 10 carbon atoms and R12 each independently represents an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, wherein said alkyl group, alkoxy group, alkenyl group or alkenyloxy group may be unsubstituted or may have one F, CH3 or CF3 as a substituent group, and/or at least one of CH2 groups existing in said alkyl group, alkoxy group, alkenyl group or alkenyloxy group may be substituted each independently with —O—, —CO— or —COO— where O atoms are not directly linked to each other, and the atoms which constitute these compounds may be replaced by their isotopes, and
• said liquid crystal component A is composed of 1 to 20 compounds;
• 0 to 95% by weight of a liquid crystal component B composed of compounds having a dielectric anisotropy of +2 or more;
• and
• 0 to 95% by weight of a liquid crystal component C composed of compounds having a dielectric anisotropy of from −10 or more to less than +2;
• wherein the total amount of the liquid crystal component B and liquid crystal component C in said nematic liquid crystal composition is from 30 to 90% by weight, with the proviso that the liquid crystal component A should satisfy at least one of the following conditions (i) to (viii):
• (i) said liquid crystal component A contains at least one compound selected from the compounds represented by said general formulae (I-11), (I-12), (I-14), (I-15), (I-17) and (I-18), and the content of said compound in said liquid crystal component A is from 5 to 100% by weight;
• (ii) said liquid crystal component A contains 1 to 10 of the compounds represented by the group A5 and 1 to 10 of the compounds represented by the group A4 and/or group A6, and the total content of these compounds in said liquid crystal component A is from 5 to 100% by weight;
• (iii) said liquid crystal component A contains 1 to 10 of the compounds represented by the group A6 and 1 to 10 of the compounds represented by the group A4 and/or group A5, and the total content of these compounds in said liquid crystal component A is from 5 to 100% by weight;
• (iv) said liquid crystal component A contains 1 to 10 of the compounds represented by the groups A4 to A6 in which the side chain group has an alkenyl group and 1 to 10 of the compounds represented by the groups A1 to A3 in which the side chain group has an alkyl group, and the total content of these compounds in said liquid crystal component A is from 5 to 100% by weight;
• (v) said liquid crystal component A contains 1 to 10 of the compounds represented by the group A3 and/or group A6 having 3,5-difluoro-4-cyanophenyl group and 1 to 10 of the compounds represented by the group A2 and/or group A5 having 3-fluoro-4-cyanophenyl group, wherein at least one of these selected compounds belongs to the group A5 or group A6, and the total content of these compounds in said liquid crystal component A is from 5 to 100% by weight;
• (vi) said liquid crystal component A contains 1 to 10 of the compounds represented by the group A3 and/or group A6 having 3,5-difluoro-4-cyanophenyl group and 1 to 10 of the compounds represented by the group A1 and/or group A4 having 4-cyanophenyl group, wherein at least one of these selected compounds belongs to the group A4 or group A6, and the total content of these compounds in said liquid crystal component A is from 5 to 100% by weight;
• (vii) said liquid crystal component A contains 1 to 10 of the compounds represented by the group A3 and/or group A6 having 3,5-difluoro-4-cyanophenyl group, 1 to 10 of the compounds represented by the group A2 and/or group A5 having 3-fluoro-4-cyanophenyl group and 1 to 10 of the compounds represented by the group A1 and/or group A4 having 4-cyanophenyl group, and the total content of these compounds in said liquid crystal component A is from 5 to 100% by weight;
• and
• (viii) said liquid crystal component A contains 1 to 10 of compounds in which R12 is represented by CH2═CH—, CH2═CH—(CH2)2—, CH2═CH—(CH2)4—, CH3CH═CH—, CH3CH═CH—(CH2)2— or CH3CH═CH—(CH2)4—.