摘要:
An antiferroelectric liquid crystal composition comprising a first component comprising at least one compound expressed by the formula (I) and exhibiting no antiferroelectric phase, and a second component comprising at least one compound expressed by the formula (II) and exhibiting an antiferroelectric phase, the contents of the first component and the second component being respectively 1 to 40% and 60 to 99%, based upon the total weight of the two components: ##STR1## wherein in the formula (I), R.sup.1 is 1-18C linear alkyl or alkoxy; R.sup.2 is 1-18C alkyl or alkoxy; k, l, m and n are 0 or 1; (k+l) and (m+n) are 1 or 2, (k+l)+(m+n) are 2 or 3; X is --OCH.sub.2 --, --CH.sub.2 O--, --COO--, --OCO-- or single bond; 6-membered rings A, B, C and D are 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl or pyridazine-3,6-diyl, one of the side-positioned hydrogen atoms of which may be replaced by halogen atom or CN, andin the formula (II), R.sup.3 is 1-18C linear alkyl or alkoxy; R.sup.4 is 2-18C alkyl or alkoxy; p, q, t and u are 0 or 1; (p+q) and (t+u) each are 1 or 2; (p+q)+(t+u) are 2 or 3; j is 0 or 1; Z is --COO--, --OCO--, --OCH.sub.2 --, --CH.sub.2 O--or single bond; Y is --CH.sub.3 ; 6-membered rings E, F, G and H are 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl or pyridazine-3,6-diyl; * shows asymmetric carbon atom.An antiferroelectric liquid crystal composition having the threshold voltage lowered at the time of transition from the antiferroelectric phase to ferroelectric phase accompanying the electric field impression in the antiferroelectric phase is provided, and a light-switching element which has a good contrast and can effect a tristable switching is obtained using the above composition.
摘要:
A 2-substituted-alkyl ether having an optically active group and useful as a component of ferroelectric liquid crystal compositions and a liquid crystal composition containing the same are provided, which 2-substituted-alkyl ether is expressed by the formula ##STR1## wherein R.sup.1 represents a linear or branched chain alkyl, alkoxy, alkanoyl, alkanoyloxy or alkoxycarbonyl of 1 to 18 C; R.sup.2 represents a linear or branched alkyl of 2 to 15 C; ##STR2## each independently represents ##STR3## wherein Y represents cyano, halogen, methyl or methoxy; X represents --OR.sup.3, ##STR4## F, Cl or Br wherein R.sup.3 represents a linear or branched alkyl group of 1 to 10 C of H; and * indicates asymmetric C.
摘要:
An optically active compound having a large spontaneous polarization ps value (ps) particularly for realizing a high speed response, and a liquid crystal composition are provided, which compound is an optically active 2,5-diphenylpyrimidine compound expressed by the formula ##STR1## wherein R.sup.1 is 1-20C alkyl or alkoxy, R.sup.2 is 1-20C alkyl, A is ##STR2## and * indicates an asymmetric carbon atom.
摘要:
An optically active compound particularly useful as a component of liquid crystal compositions having a high response rate and a chiral liquid crystal composition containing the same are provided, which optically active compound is expressed by the formula (I) ##STR1## wherein R.sup.1 represents alkyl or alkoxy each of 1-20 C, H, halogen or CN; ##STR2## and ##STR3## each represent a specified six-membered ring; R.sup.2 represents alkyl of 1-20 C; the asterisk designates an asymmetric carbon atom; and m and n each represents 0 or 1.
摘要:
Novel compounds characterized by increased spontaneous polarization values as one of the important specific features required for ferroelectric liquid crystal compositions, a liquid crystal composition containing the same, and an optical switching element utilizing the composition as a liquid crystal. The compounds are expressed by the formula (I) or (I') ##STR1##
摘要:
An optically active substance which, when added as a component of ferroelectric liquid crystal compositions, is extremely small in the reduction of the resulting liquid crystal temperature region, and a liquid crystal composition containing the same are provided, which substance is an optically active-2-alkoxy-propyl ether expressed by the formula (I) ##STR1## wherein R.sup.1 represents a straight or branched chain alkyl, alkoxy, alkanoyl, alkanoyloxy or alkoxycarbonyl each of 1 to 18 C; R.sup.2 represents a linear or branched chain alkyl each of 1 to 15 C; --A-- represents a specified group constituted by two directly bonded, six-membered rings; and * indicates asymmetric carbon atom.
摘要:
A liquid crystalline compound useful as a component of liquid crystal compositions for liquid crystal display elements, exhibiting ferroelectric liquid crystal phases over a broad temperature range including room temperature, and a liquid crystal composition containing the same are provided. The compound is a thioether compound of the formula ##STR1## wherein R.sup.1 is a 2-10C alkyl; R.sup.2 is methyl or ethyl; but the carbon number of R.sup.1 is always larger than that of R.sup.2 ; A is ##STR2## wherein X is H, halogen or CN; Y is a 1-18C alkyl or alkoxy; l is 1 or 2; and * indicates optically active carbon atom.
摘要:
The present invention provides new optically active 2,5-diphenyl pyrimidine derivatives, optically active liquid crystal compositions containing the derivatives and electro optical elements comprising the compositions.The derivatives have the following general formula: ##STR1## wherein R indicates an alkyl or alkoxy group having 2-20 carbon atoms and R* indicates an optically active alkyl group having 4-20 carbon atoms.
摘要:
An optically active liquid crystal compound useful as a component of ferroelectric liquid crystal compositions and exhibiting ferroelectric properties within a broad temperature region including room temperature and a liquid crystal composition containing the compound are provided, which compound is an optically active phenylpyrimidine compound expressed by the formula ##STR1## wherein R.sup.1 is a 1-18C alkyl group, n is an integer of 2-15 and C having * attached thereonto indicates an asymmetric carbon atom.
摘要:
An optically active-2-methylbutyrate capable of imparting a spontaneous polarization value to achiral smectic compositions and also constituting ferroelectric liquid crystal compositions exhibiting a fast response at room temperature, and a liquid crystal composition containing the same, and further a light-switching element therefrom, are provided, which optically active-2-methylbutyrate is expressed by the formula ##STR1## wherein R represents a linear or branched alkyl group or alkoxy group, each of 1 to 18 carbon atoms; A represents ##STR2## wherein X represents any one of F, Cl, Br or cyano group; and * indicates an optically active carbon atom.