Liquid crystal composition for twist nematic mode

Claim 2

A liquid crystal composition for twist nematic mode comprising a component expressed by the formula ##STR12## wherein R 1 represents an alkyl group of 1 to 8 carbon atoms, R 2 represents F or CN and n represents 1 or 2 including about 13 to about 40%, by weight, of at least one compound in which n=1 and about 14.2%, to about 60% by weight, of at least one compound in which n=2, the total proportion of said compounds of said component of formula (I) being about 42.7 to about 100%, by weight.

Claim 3

A liquid crystal composition for twist nematic mode according to claim 1 wherein said compounds represented by the formula (I) comprise a first component and further comprises a second component including at least one member selected from the group consisting of a compound expressed by the formula ##STR13## wherein R 3 represents an alkyl group of 1 to 8 carbon atoms and R 4 represents H or F; a compound expressed by the formula ##STR14## wherein R 5 represents an alkyl group of 1 to 8 carbon atoms, R 6 represents an alkoxy group of 1 to 8 carbon atoms or F, m represents 1 or 2 and X represents a single bond or --COO--, and a compound expressed by the formula ##STR15## wherein R 7 represents an alkyl group of 1 to 8 carbon atoms, R 8 represents an alkyl group or alkoxy group each of 1 to 8 carbon atoms, F or CN group and ##STR16##

Claim 4

A liquid crystal composition for twist nematic mode according to claim 2, wherein the proportion of the compound of the formula (II) is 25% by weight or less, that of the compound of the formula (III) is 30% by weight or less and that of the compound of the formula (IV) is 35% by weight or less.

Claim 5

A liquid crystal display element including a liquid crystal composition for twist nematic mode as set forth in claim 1.

Claim 6

A liquid crystal display element including a liquid crystal composition for twist nematic mode as set forth in claim 2.

Claim 7

A liquid crystal composition for twist nematic mode according to claim 1 wherein said composition exhibits an absolute value of temperature dependency, dV/dt, of less than 0.43.

Claim 8

A liquid crystal composition for twist nematic mode according to claim 2 wherein said composition exhibits an absolute value of temperature dependency, dV/dt, of less than 0.43.

Claim 9

A liquid crystal composition for twist nematic mode according to claim 6 wherein said composition has an optical anisotropy value of no more than 0.11.

Claim 10

A liquid crystal composition for twist nematic mode according to claim 7 wherein said composition has an optical anisotropy value of no more than 0.11.

Claim 11

A liquid crystal composition for twist nematic mode according to claim 1 wherein R 1 represents ethyl, propyl or pentyl.

Claim 12

A liquid crystal composition for twist nematic mode according to claim 2 wherein R 3 represents ethyl or propyl.

Claim 13

A liquid crystal composition for twist nematic mode according to claim 2 wherein R 5 represents propyl, butyl or pentyl.

Claim 14

A liquid crystal composition for twist nematic mode according to claim 2 wherein R 6 represents ethoxy.

Claim 15

A liquid crystal composition for twist nematic mode according to claim 2 wherein R 7 represents ethyl or propyl.

Claim 16

A liquid crystal composition for twist nematic mode according to claim 2 wherein R 8 represents methyl or propyl.

Claim 17

A liquid crystal composition for twist nematic mode according to claim 2 wherein R 8 represents methoxy.

Claim 18

A liquid crystal composition for twist nematic mode according to claim 1 comprising, by weight, the compounds of formula (I): ______________________________________ 4-(trans-4-ethylcyclohexyl)-2-fluorobenzonitrile 20%, 4-(trans-4-propylcyclohexyl)-2-fluorobenzonitrile 20%, 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl]-1,2- 20% difluorobenzene, 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-1,2- 20% difluorobenzene, and 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl}-2- 20% fluorobenzonitrile. ______________________________________

Claim 19

A liquid crystal composition for twist nematic mode according to claim 1 comprising, by weight, the compounds of formula (I): ______________________________________ 4-(trans-4-ethylcyclohexyl)-2-fluorobenzonitrile 14.3%, 4-(trans-4-propylcyclohexyl)-2-fluorobenzonitrile 14.2%, and 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-2- 14.2% fluorobenzonitrile; the compounds of the formula (II): 2-(3,4-difluorophenyl)-5-propylpyrimidine 9.5% and 2-(4-fluorophenyl)-5-ethylpyrimidine 14.3%; and the compounds of the formula (IV): 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}toluene 9.5%, 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl} 19% propylbenzene, and 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl} 5% benzonitrile. ______________________________________

Claim 20

A liquid crystal composition for twist nematic mode according to claim 1 comprising, by weight, the compounds of formula (I): ______________________________________ 4-(trans-4-ethylcyclohexyl)-2-fluorobenzonitrile 15%, 4-(trans-4-propylcyclohexyl)-2-fluorobenzonitrile 10%, 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl}-1,2- 15% difluorobenzene, 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-1,2- 15% difluorobenzene, 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl}-2- 15% fluorobenzonitrile, and 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-2- 15% fluorobenzonitrile. ______________________________________

Claim 21

A liquid crystal composition for twist nematic mode according to claim 2 comprising, by weight, the compounds of formula (I): ______________________________________ 4-(trans-4-ethylcyclohexyl)-2-fluorobenzonitrile 7%, 4-(trans-4-propylcyclohexyl)-2-fluorobenzonitrile 6%, 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl}-1,2- 7% difluorobenzene, 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-1,2- 7% difluorobenzene, 4-{trans-4-(trans-4-pentylcyclohexyl)cyclohexyl}-2- 3% difluorobenzene, 4-{trans-4-ethylcyclohexyl)cyclohexyl}-2- 13% fluorobenzonitrile and 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-2- 13% fluorobenzonitrile, a compound of the formula (II): 2-(3,4-difluorophenyl)-5-propylpyrimidine 11%; and the compounds of the formula (III): 4-ethoxyphenyl trans-4-propylcyclohexanecarboxylate 8% 4-ethoxyphenyl trans-4-butylcyclohexanecarboxylate 8%, and 4-butoxyphenyl trans-4-butylcyclohexanecarboxylate 9% ______________________________________

Claim 22

A liquid crystal composition for twist nematic mode according to claim 2 comprising, by weight, the compounds of formula (I): ______________________________________ 4-(trans-4-pentylcyclohexyl)-1,2-difluorobenzene 10% 4-(trans-4-ethylcyclohexyl)-2-fluorobenzonitrile 10% 4-(trans-4-propylcyclohexyl)-2-fluorobenzonitrile 10% 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl}-1,2- 15% difluorobenzene, 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-1,2- 10% fluorobenzonitrile, and 4-{trans-4-(trans-4-propylcyclohexyl}-2- 10% fluorobenzonitrile; and a compound of the formula (IV): 4-{trans-4-(trans-4-ropylcyclohexyl)cyclohexyl} 10% propylbenzene. ______________________________________

Claim 23

A liquid crystal composition for twist nematic mode according to claim 2 comprising, by weight, the compounds of formula (I): ______________________________________ 4-(trans-4-ethylcyclohexyl)-2-fluorobenzonitrile 12.2% 4-(trans-4-propylcyclohexyl)-2-fluorobenzonitrile 14.6% 4-(trans-4-pentylcyclohexyl)-2-difluorobenzonitrile 12.2% 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl)}-1,2- 13.4% difluorobenzene, 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-1,2- 13.4% difluorobenzene, and 4-{trans-4-pentylcyclohexyl)cyclohexyl}-1,2- 13.4% difluorobenzene; the compounds of the formula (III): 4-fluorophenyl trans-4-(trans-4-propylcyclohexyl)- 4.9% cyclohexanecarboxylate, and 4-fluorophenyl trans-4-(trans-4-pentylcyclohexyl)- 4.9% cyclohexanecarboxylate; and the compounds of the formula (IV): 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}- 6.1% fluorobenzene, and 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl} 4.0% methoxybenzene. ______________________________________

Claim 24

A liquid crystal composition for twist nematic mode according to claim 2 comprising, by weight, the compounds of formula (I): ______________________________________ 4-(trans-4-ethylcyclohexyl)-2-fluorobenzonitrile 12%, 4-(trans-4-propylcyclohexyl)-2-fluorobenzonitrile 12%, 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl}-1,2- 15% difluorobenzene, 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-1,2- 15% difluorobenzene, and 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}-2- 8% fluorobenzonitrile; a compound of the formula (II): 2-(4-fluorophenyl-5-ethylpyrimidine and two compounds of the formula (IV): 4-{trams-4-(trans-4-propylcyclohexyl)cyclohexyl}toluene 9% and 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}- 14% propylbenzene. ______________________________________

Claim 25

A liquid crystal composition for twist nematic mode according to claim 2 comprising, by weight, the compounds of formula (I): ______________________________________ 4-(trans-4-ethylcyclohexyl)-2-fluorobenzonitrile 15%, 4-(trans-4-propylcyclohexyl)-2-fluorobenzonitrile 15%, 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl}-1,2- 15%, difluorobenzene 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}1,2- 15%, and difluorobenzene 4-{trans-4-(trans-4-pentylcyclohexyl)cyclohexyl}-1,2- 10%; difluorobenzene a compound of the formula (III): 4-{trans-4-propylcyclohexyl)ethoxybenzene 8%; the compounds of the formula (IV): 4-{trans-4-(trans-4-propylcyclohexyl)cyclohexyl}- 6% and benzonitrile 4-{trans-4-(trans-4-ethylcyclohexyl)cyclohexyl}- 6%. benzonitrile ______________________________________