Patent ID: 6096242
Filing Date: 2000-08-01
Classification: C09K

Abstract:
A liquid crystal composition comprising at least two components, in which the first component is at least one selected from the compounds of formula (1) ##STR10## wherein m is 0 or 1; each of A.sup.1, A.sup.2 and A.sup.3 represents a 6-membered ring; each of Z.sup.1 and Z.sup.2 represents a bridge between the rings; and R.sup.1 represents a terminal group selected from a straight or branched hydrocarbon group of 1-10 carbons which may contain one or more ether bonds (--O--) in the chain; which include(a) a bicyclic compound wherein m is 0; ring A.sup.1 is trans-1,4-cyclohexylene, 1,4-phenylene, 2,6-dioxan-1,4-diyl or 2,6-pyrimidine-1,4-diyl, in which the carbon atom in the ring bound to bridge Z.sup.1 is defined as 1-position; ring A.sup.2 is trans-1,4-cyclohexylene or 1,4-phenylene; and bridge Z.sup.1 is ethylene (--CH.sub.2 CH.sub.2 --), carbonyloxy (--COO--) or a covalent bond (--); and(b) a tricyclic compound wherein m is 1; rings A.sup.1, A.sup.2 and A.sup.3 are each independently trans-1,4-cyclohexylene or 1,4-phenylene; bridge Z.sup.1 is a covalent bond (--); and bridge Z.sup.2 is ethylene (--CH.sub.2 CH.sub.2 --) or a covalent bond (--);and the second component is at least one selected from the compounds of formula (2)R.sup.2 --A.sup.4 --Z.sup.3 --(--A.sup.6 --Z.sup.4 --).sub.n --(--A.sup.7 --Z.sup.5 --).sub.p --A.sup.5 --R.sup.3 ( 2)wherein n and p are each independently 0 or 1; each of A.sup.4, A.sup.5, A.sup.6 and A.sup.7 represents a six-membered ring; each of Z.sup.3, Z.sup.4 and Z.sup.5 represents a bridge between the rings; and both R.sup.2 and R.sup.3 represent a terminal group; which include(a) a bicyclic compound wherein n and p are 0; ring A.sup.4 is trans-1,4-cyclohexylene, 1,4-phenylene or 2,6-pyrimidine-1,4-diyl, in which the carbon atom in the ring bound to bridge Z.sup.3 is defined as 1-position; ring A.sup.5 is trans-1,4-cyclohexylene or 1,4-phenylene; bridge Z.sup.3 is ethynylene, ethenylene (--CH.dbd.CH--), ethylene (--CH.sub.2 CH.sub.2 --), carbonyloxy (--COO--) or a covalent bond (--); and R.sup.2 and R.sup.3 are each independently a straight or branched, saturated or unsaturated hydrocarbon group of up to 10 carbons which may contain one or more ether bonds (--O--) in the chain and wherein one or more H's may be substituted by F;(b) a tricyclic compound wherein n is 1; p is 0; ring A.sup.4 is trans-1,4-cyclohexylene or 2,6-pyrimidine-1,4-diyl, in which the carbon atom in the ring bound to Z.sup.3 is defined as 1-position; ring A.sup.5 is trans-1,4-cyclohexylene or 1,4-phenylene; ring A.sup.6 is trans-1,4-cyclohexylene or 1,4-phenylene which may be substituted by one or more F's; bridge Z.sup.3 is ethylene (--CH.sub.2 CH.sub.2 --), ethenylene (--CH.dbd.CH--), carbonyloxy (--COO--) or a covalent bond (--); bridge Z.sup.4 is ethynylene, ethenylene (--CH.dbd.CH--), carbonyloxy (--COO--) or a covalent bond (--); and R.sup.2 and R.sup.3 are each independently a straight or branched, saturated or unsaturated hydrocarbon group of up to 10 carbons which may contain one or more ether bonds (--O--) in the chain and in which one or more H's may be substituted by F; and(c) a tetracyclic compound wherein n and p are 1; rings A.sup.4 and A.sup.5 are trans-1,4-cyclohexylene; ring A.sup.6 is 1,4-phenylene in which the adjacent position to the carbon atom bound to Z.sup.4 may be substituted by F; ring A.sup.7 is 1,4-phenylene; any of bridges Z.sup.3, Z.sup.4 and Z.sup.5 is a covalent bond (--); and R.sup.2 and R.sup.3 are independently a straight or branched, saturated or unsaturated hydrocarbon group of up to 10 carbons.