US 5,851,426 AGranted

Twisted nematic liquid crystal composition containing a silacyclohexane compound

AssigneeShin-Etsu Chemical Co., Ltd.

InventorsTakaaki Shimizu, Tatsushi Kaneko, Tsutomu Ogihara, Mutsuo Nakashima

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Abstract

This invention provides twisted nematic liquid crystal compositions obtained by adding a cyclohexane ring-containing optically active compound of the following general formula (1) to a mixture of nematic liquid crystal compounds including at least one silacyclohexane compound, as well as guest-host liquid crystal compositions and liquid crystal display devices utilizing the same. ##STR1##

Claims8

Dependent claims

A twisted nematic liquid crystal composition comprising:

(a) an optically active silacyclohexane compound of the general formula (1) ##STR56## wherein R is a linear C.sub.1-10 alkyl group, a branched C.sub.3-8 alkyl group, a C.sub.2-7 alkoxyalkyl group, a C.sub.1-10 mono- or difluoroalkyl group, or a C.sub.2-8 alkenyl group, ##STR57## is a trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group in which the silicon atom at the 1- or 4-position has a substituent comprising H, F, Cl or CH.sub.3, or is a 1,4-cyclohexylene group, ##STR58## is a trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group in which the silicon atom at the 1- or 4-position has a substituent comprising H, F, Cl or CH.sub.3, or is a 1,4-cyclohexylene or 1,4-phenylene group,
n is 0 or 1, E is --CH.sub.2 -- or --O--, Z is a chiral group containing one or more chiral carbon atoms, and is selected from the group consisting of
--(CH.sub.2).sub.a --C*R.sub.o G--C.sub.b H.sub.2b+1 ( 12a)
wherein a is an integer of 0 to 8, b is an integer of 2 to 14, R.sub.0 is hydrogen or a linear C.sub.1-6 alkyl group, G is CH.sub.3, halogen, CF.sub.3, CHF.sub.2, CH.sub.2 F or CN, and C* is a chiral carbon atoms which has four different substituents, so that three substituents, R.sub.0, G, and --C.sub.b H.sub.2b+1 are different from each other,
--(CH.sub.2).sub.c --CHF--(CH.sub.2).sub.d --CHF--C.sub.e H.sub.2e+1( 12b)
wherein c is an integer of 0 to 8, d is an integers of 0 to 6, and e is an integer of 1 to 10
and ##STR59## wherein c is an integer of 0 to 8, and e is an integer 1 to 10, and L.sub.1 and L.sub.2 are each independently H or F,
the silacyclohexane compound containing at least one trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group;
and
(b) a liquid crystal composition comprising one or more compounds selected from the group consisting of the compounds of the general formula (2) to (7) ##STR60## wherein R' is a C.sub.1-7 alkyl group, a C.sub.2-7 alkoxyalkyl group, a C.sub.2-7 mono- or difluoroalkyl group, or a C.sub.2-7 alkenyl group, m is 0 or 1, ##STR61## are each independently a trans-1-sila-1,4-cyclohexylene, trans-4-sila-1,4-cyclohexylene or trans-1,4-cyclohexylene group,
X is H, CN, F, Cl, OCHF.sub.2, OCF.sub.3, CF.sub.3, OC.sub.k H.sub.2k+1 (wherein k is an integer of 1 to 5), C.sub.k H.sub.2k+1, (O).sub.s C.sub.p H.sub.q F.sub.r (wherein p is 2, 3 or 4, q and r are such integers that (q+r) is equal to (2p+1), and s is 0 or 1) or (O).sub.s CY.dbd.CX.sub.1 X.sub.2 (wherein X.sub.1 and Y are each H, F or Cl, X.sub.2 is F or Cl, and s is 0 or 1), and
Y.sub.1, Y.sub.2, Y.sub.3 and Y.sub.4 are each independently H or F, at least one of the compounds being a compound containing a trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group.

9 more elements

Dependencies are inferred from the claim text.

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Abstract

A twisted nematic liquid crystal composition comprising:

(a) an optically active silacyclohexane compound of the general formula (1) ##STR56## wherein R is a linear C.sub.1-10 alkyl group, a branched C.sub.3-8 alkyl group, a C.sub.2-7 alkoxyalkyl group, a C.sub.1-10 mono- or difluoroalkyl group, or a C.sub.2-8 alkenyl group, ##STR57## is a trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group in which the silicon atom at the 1- or 4-position has a substituent comprising H, F, Cl or CH.sub.3, or is a 1,4-cyclohexylene group, ##STR58## is a trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group in which the silicon atom at the 1- or 4-position has a substituent comprising H, F, Cl or CH.sub.3, or is a 1,4-cyclohexylene or 1,4-phenylene group,
n is 0 or 1, E is --CH.sub.2 -- or --O--, Z is a chiral group containing one or more chiral carbon atoms, and is selected from the group consisting of
--(CH.sub.2).sub.a --C*R.sub.o G--C.sub.b H.sub.2b+1 ( 12a)
wherein a is an integer of 0 to 8, b is an integer of 2 to 14, R.sub.0 is hydrogen or a linear C.sub.1-6 alkyl group, G is CH.sub.3, halogen, CF.sub.3, CHF.sub.2, CH.sub.2 F or CN, and C* is a chiral carbon atoms which has four different substituents, so that three substituents, R.sub.0, G, and --C.sub.b H.sub.2b+1 are different from each other,
--(CH.sub.2).sub.c --CHF--(CH.sub.2).sub.d --CHF--C.sub.e H.sub.2e+1( 12b)
wherein c is an integer of 0 to 8, d is an integers of 0 to 6, and e is an integer of 1 to 10
and ##STR59## wherein c is an integer of 0 to 8, and e is an integer 1 to 10, and L.sub.1 and L.sub.2 are each independently H or F,
the silacyclohexane compound containing at least one trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group;
and
(b) a liquid crystal composition comprising one or more compounds selected from the group consisting of the compounds of the general formula (2) to (7) ##STR60## wherein R' is a C.sub.1-7 alkyl group, a C.sub.2-7 alkoxyalkyl group, a C.sub.2-7 mono- or difluoroalkyl group, or a C.sub.2-7 alkenyl group, m is 0 or 1, ##STR61## are each independently a trans-1-sila-1,4-cyclohexylene, trans-4-sila-1,4-cyclohexylene or trans-1,4-cyclohexylene group,
X is H, CN, F, Cl, OCHF.sub.2, OCF.sub.3, CF.sub.3, OC.sub.k H.sub.2k+1 (wherein k is an integer of 1 to 5), C.sub.k H.sub.2k+1, (O).sub.s C.sub.p H.sub.q F.sub.r (wherein p is 2, 3 or 4, q and r are such integers that (q+r) is equal to (2p+1), and s is 0 or 1) or (O).sub.s CY.dbd.CX.sub.1 X.sub.2 (wherein X.sub.1 and Y are each H, F or Cl, X.sub.2 is F or Cl, and s is 0 or 1), and
Y.sub.1, Y.sub.2, Y.sub.3 and Y.sub.4 are each independently H or F, at least one of the compounds being a compound containing a trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group.

9 more elements