US 5,688,437 A · Liquid crystal composition, liquid crystal device using the composition, liquid crystal apparatus and display method

Abstract

A liquid crystal composition includes a liquid crystal containing at least one mesomorphic compound having a cholesteric phase (Ch phase)-free mesomorphic phase, and at least one compound (e) having a limit of solubility in the liquid crystal and being contained in the composition in a proportion ranging from 20% of the limit of solubility to below the limit of solubility. The liquid crystal composition may preferably include the liquid crystal containing at least one fluorine-containing mesomorphic compound (a) having a fluorocarbon terminal portion and a hydrocarbon terminal portion, and at least one achiral compound (b), a the compound (e), having a specific ring structure and a specific terminal alkyl group free from a perfluorocarbon atom. The compound having a Ch phase-free mesomorphic phase, preferably the compound (a), and the compound (e), preferably the compound (b) are effective in providing the liquid crystal composition with a layer structure of so-called bookshelf or a layer structure having a small inclination angle (closer to bookshelf structure). The liquid crystal composition is useful in improving response characteristics and display characteristics, particularly a contrast ratio, of a liquid crystal device using the liquid crystal composition.

A liquid crystal composition, comprising:

at least one fluorine-containing mesomorphic compound (a) represented by the following formula (I):
##STR71## in which B, D and F independently denote ##STR72## a, b and c independently denote an integer of 0-3 with the proviso that a+b+c is at least 2;
M and N independently denote --COO--, --OCO--, --COS--, --SCO--, --COSe--, --SeCO--, --COTe--, --TeCO--, .paren open-st.CH.sub.2 CH.sub.2).sub.d wherein d is an integer of 1-4, --CH.dbd.CH--, --C.tbd.C--, --CH.dbd.N--, --N.dbd.CH--, --CH.sub.2 O--, --OCH.sub.2 --, --CO--, --O-- or a single bond;
X, Y and Z independently denote --H, --Cl, --F, --Br, --I, --OR, --OCH.sub.3, --CF.sub.3, --OCF.sub.3 --, --CH.sub.3, --CN or --NO.sub.2 and l, m and n independently denote an integer of 0-4;
G is --COO--C.sub.e H.sub.2e --, --O--C.sub.e H.sub.2e --, --C.sub.e H.sub.2e --, --OSOO--, --OOSO--, --SOO--, --SOOC.sub.e H.sub.2e --, --O(C.sub.e H.sub.2e --O).sub.q C.sub.e' H.sub.2e', --C.sub.e H.sub.2e --N(C.sub.p H.sub.2p+1)--SO.sub.2 --, --C.sub.e H.sub.2e --N(C.sub.p H.sub.2p+1)--CO-- wherein e and e' independently denote an integer of 1-20, q is an integer of 1-6 and p is an integer of 0-4;
A is a linear or branched group represented by --O.paren open-st.C.sub.f H.sub.2f .paren close-st..sub.w O--C.sub.g H.sub.2g+1, .paren open-st.C.sub.f H.sub.2f --O.paren close-st..sub.w C.sub.g H.sub.2g+1, --C.sub.f H.sub.2f --R', --O--C.sub.f H.sub.2f --R', --COO--C.sub.f H.sub.2f --R', --OCO--C.sub.f H.sub.2f --R' wherein R' is --Cl, --F, --CF.sub.3, --NO.sub.2, --CN, --H, --COO--C.sub.f' H.sub.2f'+1 or --OCO--C.sub.f' H.sub.2f'+1 in which f, f' and g independently denote an integer of 1-20 and w is an integer of 1-10;
and
R is .paren open-st.C.sub.x F.sub.2x O.paren close-st..sub.z C.sub.y F.sub.2y+1 wherein x is independently an integer of 1-10 for each C.sub.x F.sub.2x O group, y is an integer of 1-10, and z is an integer of 1-10;
and
at least one achiral compound (b) selected from the group consisting of those represented by the following formulae (IV) to (XVI) shown below:
##STR73## in which A.sup.2 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.2 is a single bond, --O--, --COO-- or --OCO--;
and D.sup.2 is a linear or branched alkyl group having 1-20 carbon atoms;
##STR74## in which A.sup.3 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.3, B.sup.3' and B.sup.3" independently denote a single bond, --O--, --COO-- or --OCO--;
and D.sup.3 is a linear or branched alkyl group having 1-20 carbon atoms;
##STR75## in which A.sup.4 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.4, B.sup.4' and B.sup.4" independently denote a single bond, --O--, --COO-- or --OCO--;
and D.sup.4 is a linear or branched alkyl group having 1-20 carbon atoms;
##STR76## in which A.sup.5 is a linear or branched alkyl group having, 1-20 carbon atoms;
B.sup.5, B.sup.5' and B.sup.5" independently denote a single bond, --O--, --COO-- or --OCO--;
and D.sup.5 is a linear or branched alkyl group having 1-20 carbon atoms;
##STR77## in which A.sup.6 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.6, B.sup.6' and B.sup.6" independently denote a single bond, --O--, --COO-- or --OCO--;
and D.sup.6 is a linear or branched alkyl group having 1-20 carbon atoms;
##STR78## in which A.sup.7 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.7, B.sup.7' and B.sup.7" independently denote a single bond, --O--, --COO-- or --OCO--;
D.sup.7 is a linear or branched alkyl group having 1-20 carbon atoms;
and E.sup.7 is 1,4-phenylene or 2,6-naphthylene;
##STR79## in which A.sup.8 is a linear or branched alkyl group having 1-30 carbon atoms;
B.sup.8, B.sup.8' and B.sup.8" independently denote a single bond, --O--, --COO-- or --OCO--;
D.sup.8 is a linear or branched alkyl group having 1-20 carbon atoms;
and a.sup.8 is 1 or 2;
##STR80## in which A.sup.9 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.9 and B.sup.9' independently denote a single bond, --O--, --COO-- or --OCO--;
D.sup.9 is a linear or branched alkyl group having 1-20 carbon atoms;
and X.sup.9 is --H or --F;
##STR81## in which A.sup.10 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.10, B.sup.10' and B.sup.10" independently denote a single bond, --O--, --COO-- or --OCO--;
and D.sup.10 is a linear or branched alkyl group having 1-20 carbon atoms;
##STR82## in which A.sup.11 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.11, B.sup.11' and B.sup.11" independently denote a single bond, --O--, --COO-- or, --OCO--;
D.sup.11 is a linear or branched alkyl group having 1-20 carbon atoms;
and X.sup.11 is --H or --F;
##STR83## in which A.sup.12 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.12 and B.sup.12' independently denote a single bond, --O--, --COO-- or --OCO--;
D.sup.12 is a cyano group;
and a.sup.12 and a.sup.12' are independently 1 or 2;
##STR84## in which A.sup.13 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.13 and B.sup.13' independently denote a single bond, --O--, --COO-- or --OCO--;
and D.sup.13 is a linear or branched alkyl group having 1-20 carbon atoms;
and ##STR85## in which A.sup.14 is a linear or branched alkyl group having 1-20 carbon atoms;
B.sup.14 and B.sup.14' independently denote a single bond, --O--, --COO-- or --OCO--;
X.sup.14 is --F;
and n.sup.14 is an integer of 1-5.

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Liquid crystal composition, liquid crystal device using the composition, liquid crystal apparatus and display method

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Liquid crystal composition, liquid crystal device using the composition, liquid crystal apparatus and display method

Life of this patent

Abstract

Claims64