摘要:
A liquid crystal display cell comprising a chiral ferroelectric smectic liquid crystal layer whose helix structure is influenced by the action of an electric field such that its optical anisotropy alters; a pair of transparent plates between which the liquid crystal is disposed and which have a surface structure for aligning the molecule of the liquid crystal and are provided with electrodes to produce an electric field therein; and one polariser each before and after the liquid crystal: such ratio d/p of the thickness d of the liquid crystal layer to the pitch height p of the helical twisting is greater than 5, the smectic tilt angle .theta..sub.o is being between 22.5.degree. and 50.degree. and the product d.multidot..theta..sub.o.sup.2 .multidot..DELTA.n.multidot.l/.lambda. (phase factor) of the thickness d, the square of the tilt angle .theta..sub.o, the value of the birefringence .DELTA.n and the reciprocal of the wavelength .lambda. of light bedding is greater than 0.45 .mu.m.
摘要:
The present invention is concerned with photo cross-linkable liquid crystals of the formula ##STR1## wherein A is a cross-linkable mesogenic residue;X is a single bond, --COO--, --CH.sub.2 O--, --CONH-- or --C.dbd.N--; andQ is n-alkylene, c-alkylene, 1,4-phenylene, 4,4'-biphenylene or 2,6-naphthylene;liquid crystalline mixtures which contain such compounds as well as their use in the cross-linked state for optical building elements.
摘要:
The invention is concerned with linear and cyclic polymers or oligomers having a photoreactive ethene group. The polymers are of the formula ##STR1## wherein M.sub.a, M.sub.b, M.sub.c are monomer units for homo- or copolymers;x, y, z are mole fractions of the copolymers, whereby in each case 0
摘要:
Optically active compounds of the formula ##STR1## wherein rings A, B and C each independently are unsubstituted or each are 1,4-phenylene substituted with at least one of halogen-, cyano-, methyl- or methoxy in which optionally 1 CH group or 2 CH groups is/are replaced by nitrogen; R.sup.1 is a radical of an optically active terpene alcohol after cleavage of the hydroxy group or a group --(CH.sub.2).sub.m --C*HX.sup.1 --R.sup.3 ; R.sup.2 is a radical of an optically active terpene alcohol after cleavage of the hydroxy group or a group --(CH.sub.2).sub.n --C*HX.sup.2 --R.sup.4 ; m and n each independently stand for the number 0 or 1: C* denotes a chiral carbon atom; X.sup.1 and X.sup.2 each independently are fluorine, chlorine, cyano, methyl or methoxy; R.sup.3 and R.sup.4 each independently denote a group R, phenyl or phenyl substituted with R, with the proviso that R.sup.3 is different from X.sup.1 and R.sup.4 is different from X.sup.2 ; R is an alkyl group in which optionally one methylene group is replaced by oxygen and/or optionally one group CH--CH is replaced by a group C.dbd.C; with the proviso that R.sup.1 and R.sup.2 are not simultaneously 2-alkyl when rings A, B and C together are p-terphenyl,as well as liquid crystalline mixtures and their use for electro-optical purposes.
摘要:
Compounds having the Formula: ##STR1## wherein R.sup.1 denotes an alkenyl group;A.sup.1 and A.sup.2 each independently represent 1,4-phenylene, which is unsubstituted or substituted with halogen and in which, when it is unsubstituted, optionally 1 or 2 CH group(s) is/are replaced by nitrogen, or trans-1,4-cyclohexylene or trans-1,3-dioxane-2,5-diyl;Z.sup.1 and Z.sup.2 each independently signify a single covalent bond, --CH.sub.2 CH.sub.2 --, --COO--, --OOC--, --OCH.sub.2 --, --CH.sub.2 O--, --C.dbd.C--, --(CH.sub.2).sub.4 --, --O(CH.sub.2).sub.3 --, --(CH.sub.2).sub.3 O-- or the trans form of --OCH.sub.2 CH.dbd.CH--, --CH.dbd.CHCH.sub.2 O--, --(CH.sub.2).sub.2 CH.dbd.CH-- or --CH.dbd.CH(CH.sub.2).sub.2 --;n is either 0, 1 or 2; andR.sup.2 is halogen, cyano or alkyl with 1 to 12 carbon atoms, which is optionally substituted with fluorine and in which optionally 1 --CH.sub.2 -- group or 2 non-adjacent --CH.sub.2 -- groups is/are replaced by oxygen, --COO--, --OOC--, --CO-- and/or a --CH.sub.2 --CH.sub.2 -- group is replaced by --CH.dbd.CH--,are useful in electro-optical applications. Liquid crystalline mixtures containing such compounds are especially suitable for use in commercial applications, such as electro-optic cells.
摘要:
Compounds of general formula (I), wherein R signifies hydrogen, halogen, cyano, isothiocyanato, or alkyl, alkenyl or alkynyl with 1 to 15 carbon atoms, which is unsubstituted or substituted with at least one of halogen, cyano and/or trifluoromethyl and in which one or more non-adjacent --CH.sub.2 -- group(s) can be replaced by --O--, --S--, --CO--, --COO-- and/or --OOC--; Q represents alkylene with 2 to 10 carbon atoms, which is unsubstituted or substituted with at least one fluorine and in which one --CH.sub.2 -- group can be replaced by --O--, --S--, --COO--, or --OOC--, or --CH.sub.2 --, --CF.sub.2 --, --CHF-- or a single covalent bond; A.sup.1, A.sup.2, A.sup.3 each independently signify 1,4-phenylene, which is unsubstituted or substituted with at least one of halogen, cyano and/or methyl and in which, when it is unsubstituted, one or more --CH-- groups can be replaced by nitrogen, or unsubstituted or cyano- or fluoro-substituted trans-1,4-cyclohexylene, or 1,4-cyclohexenylene, trans-1,3-dioxane-2,5-diyl or trans-1,3-dithiane-2,5-diyl; A.sup.4 represents unsubstituted or cyano- or fluoro-substituted trans-1,4-cyclohexylene, or 1,4-cyclohexenylene, trans-1,3-dioxane-2,5-diyl, trans-1,3-dithiane-2,5-diyl or, when Q is different from a single covalent bond, also 1,4-phenylene, which is unsubstituted or substituted with at least one of halogen, cyano and/or methyl and in which, when it is unsubstituted, one or more --CH-- groups can be replaced by nitrogen; X.sup.1 represents bromine or chlorine; Z.sup.1, Z.sup.2, Z.sup.3 each independently denote a single covalent bond, --CH.sub.2 O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 --, --COO--, --OOC--, --C.tbd.C--, --(CH.sub.2).sub.4 --, --(CH.sub.2).sub.3 O--, --O(CH.sub.2).sub.3 --, the trans form of --CH.dbd.CH--, --CH.dbd.CHCH.sub.2 O--, --OCH.sub.2 CH.dbd.CH--, --CH.dbd.CH(CH.sub.2).sub.2 -- or --(CH.sub.2).sub.2 CH.dbd.CH--; n, p each independently signify 0 or 1; R.sup.2, R.sup.3 each independently represent hydrogen or fluorine, as well as liquid crystalline mixtures which contain such compounds and their use for electro-optical purposes.
摘要:
A bistable ferroelectric liquid crystal display cell utilizes two plates, a chiral ferroelectric smectic liquid crystal sandwiched between the plates, and an electrode for applying an electrical field to the plates. The chiral ferroelectric smectic liquid crystal has a structure which is influenced by the action of an electric field so that its optical anisotropy changes. By using a first polarizer connected to one of the plates and a second polarizer connected to the other plate, the unique bistable ferroelectric display produces dark parallel stripes when the polarizers are in a cross position relative to each other.
摘要:
Compounds of the formula ##STR1## wherein n stands for the number 0 or 1; the rings A.sup.1, A.sup.2 and A.sup.3 represent 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also represents a 2,5-disubstituted pyrimidine ring or a trans-2,5-disubstituted m-dioxane ring; X.sup.1 represents a single covalent bond, --COO--, --OOC--, --CH.sub.2 CH.sub.2 --, p--C.sub.6 H.sub.4 --, --CH.sub.2 CH.sub.2 --p-- C.sub.6 H.sub.4 --, --CH.sub.2 CH.sub.2 --p--C.sub.6 H.sub.4 --CH.sub.2 CH.sub.2 -- or, insofar as the rings A.sup.1 and A.sup.2 represent 1,4-phenylene, also --NON--; R.sup.2 represents 1E-alkenyl, 2Z-alkenyl, 3E-alkenyl, 4-alkenyl or alkenyloxy, with the proviso that the oxygen atom in alkenyloxy is linked with a saturated carbon atom; and R.sup.1 signifies 1E-alkenyl, 2Z-alkenyl, 3E-alkenyl, 4-alkenyl or, insofar as R.sup.2 represents alkenyloxy, also alkyl, their manufacture, as well as liquid crystalline mixtures and the use for electro-optical purposes.
摘要:
This invention concerns compounds of the formula: ##STR1## wherein X is a single covalent bond, --CH.sub.2 CH.sub.2 --, 1,4-phenylene, a 2,5-disubstituted pyrimidine ring or a group of the formula: ##STR2## ring A is trans-1,4-cyclohexylene or, when X is a single covalent bond, ring A may also be 1,4-phenylene, a 2,5-disubstituted pyrimidine ring or a trans-2,5-disubstituted m-dioxane ring; andR.sup.1 is straight-chain trans-1-alkenyl having 2 to 12 carbon atoms or straight-chain trans-3-alkenyl having 4 to 12 carbon atoms or, when X is --CH.sub.2 CH.sub.2 --, R.sup.1 may also be 1,4-phenylene, a 2,5-disubstituted pyrimidine ring or a group of formula IA or when ring A is a 2,5-disubstituted pyrimidine ring of a trans-2,5-disubstituted m-dioxane ring, R.sup.1 may also be straight-chain alkyl with 1 to 12 carbon atoms; and one of the benzene rings may have a lateral fluorine substituent;their manufacture, and liquid crystalline mixtures and electro-optical device containing same.
摘要:
Compounds of the formula ##STR1## wherein m represents is the number 0 or 1; A is a single covalent bond, --CH.sub.2 --CH.sub.2 --, --OCH.sub.2 --, --COO-- or --OOC--; rings B, C and D are 1,4-phenylene optionally substituted with cyano, halogen or lower alkyl; Y.sup.1 and Y.sup.2 are hydrogen or one of them also is cyano; and R.sup.1 and R.sup.2 each represents C.sub.1 -C.sub.18 -alkyl or C.sub.2 -C.sub.18 alkenyl, either of which is optionally halogen-substituted, in which one CH.sub.2 group or two non-adjacent CH.sub.2 groups is/are optionally replaced by oxygen; with the provisos that at least one of R.sup.1 and R.sup.2 has a chiral carbon atom or a C--C double bond or both when A is --COO-- and at least one of R.sup.1 and R.sup.2 has a C--C double bond when A is a single covalent bond, their preparation, liquid crystalline mixtures containing these compounds and their use for electro-optical purposes are described.