Abstract: Novel anti-ferroelectric liquid crystal compounds of the formula (1), ##STR1## wherein R is a linear alkyl group having 6 to 12 carbon atoms, X is a hydrogen atom or a fluorine atom, n is an integer of 2 to 7, p is an integer of 0 to 2 and C* is an asymmetric carbon atom. The above anti-ferroelectric liquid crystal compounds have an anti-ferroelectric phase in a broad temperature range and have a low melting point, so that they can be advantageously used as a main component for a practically valuable liquid crystal material or as a component for a liquid crystal composition.

Abstract: A racemic compound of the formula (1) ##STR1## and an anti-ferroelectric liquid crystal composition consisting essentially of said racemic compound and one anti-ferroelectric liquid crystal compound of the formula (2) or a mixture of two or more compounds selected from anti-ferroelectric liquid crystal compounds of the formula (2), ##STR2## said composition having excellent steepness of threshold, having an anti-ferroelectric phase in a broad temperature range and having the performance of a high response speed and a high contrast.

Abstract: A novel R-configuration or S-configuration optically active alcohol of the formula (1),CF.sub.3 C*H(OH)(CH.sub.2).sub.m OCH.sub.2 CH.sub.n F.sub.3-n(1)wherein C* is an asymmetric carbon atom, m is an integer of 2 to 7, and n is an integer of 0 to 2, and a process for the production of the optically active alcohol from a monohalogenated alkyl having a fluoroalkoxy group at a terminal. The novel optically active alcohol, provided by the present invention, having a trifluoromethyl group on an asymmetric carbon atom and a fluoroalkoxy group at a terminal, is useful as a raw material for the production of a novel liquid crystal compound.

Abstract: A swallow-tailed compound of the following general formula (1), ##STR1## wherein m is an integer of 4 to 10, n is an integer of 2 to 6, p is 0 or 1 and each of X and Y is independently a hydrogen or fluorine atom; and a ferrielectric liquid crystal composition consisting essentially of the swallow-tailed compound of the general formula (1) and a ferrielectric liquid crystal compound of the following general formula (2), ##STR2## wherein R is a linear alkyl group having 6 to 12 carbon atoms, Z is a hydrogen or fluorine atom, r is an integer of 2 to 4 and s is an integer of 2 to 4. The ferrielectric liquid crystal composition has a ferrielectric phase in a broad temperature range and attains a fast response and a large tilt angle in a broad temperature range so that a ferrielectric liquid crystal display device having high display qualities can be provided.

Abstract: A process for the production of an intermediate for a liquid crystal compound, which comprises reacting an alkyloxybiphenylcarboxylic acid with purified thionyl chloride substantially free of sulfuryl chloride, the thionyl chloride being obtained by adding phenol, etc., to thionyl chloride, heating the mixture and distilling the resultant mixture; and a process for the production of a liquid crystal compound from the above intermediate. According to the present invention, thionyl chloride can be easily purified, and a liquid crystal compound having a very high purity can be obtained by the use of the purified thionyl chloride.

Abstract: ?I! An optically active compound of the formula (1), ##STR1## wherein R.sup.1 is a linear alkyl group, each of X.sup.1 and X.sup.2 is a hydrogen atom or one of X.sup.1 and X.sup.2 is a hydrogen atom and the other is a fluorine atom, each of Y.sup.1 and Y.sup.2 is a hydrogen atom or one of Y.sup.1 and Y.sup.2 is a hydrogen atom and the other is a fluorine atom, m is an integer of 3 to 10, and C* is an asymmetric carbon atom,?II! an anti-ferroelectric liquid crystal composition consisting essentially of the optically active compound of the above formula (1) and a compound of the formula (2), ##STR2## and ?III! a ferrielectric liquid crystal composition consisting essentially of the optically active compound of the formula (1) and a compound of the formula (3).

Abstract: A process for the production of a phenol derivative of the formula (2), which comprises subjecting a diester compound of the formula (1) in which a hydroxyl group is protected by an acyl group, to a reaction for removal of protection, wherein the reaction is carried out in the presence of an aliphatic amine as a protection-removal agent, ##STR1## wherein X is hydrogen or fluorine, Y is --CH.sub.3 or --CF.sub.3, Q is an alkyl group having 1 to 4 carbon atoms, p is 0 or 1, m is an integer of 2 to 7, n is an integer of at least 1, and C* is an asymmetric carbon,the process enabling to obtain the phenol derivative of the formula (2) useful as an intermediate for a liquid crystal compound with ease and at high purity.

Abstract: A liquid crystal compound of the formula (1) ##STR1## wherein R is a linear alkyl group having 6 to 12 carbon atoms,both X and Y are hydrogen atoms or one of X and Y is a fluorine atom and the other is a hydrogen atom,A is --CF.sub.3 or --C.sub.2 F.sub.5,m is an integer of 2 to 4,n is an integer of 2 to 4, andC* is an asymmetric carbon,having a ferrielectric phase in its phase sequence, or a ferrielectric liquid crystal composition containing the liquid crystal compound of the formula (1) having a ferrielectric phase, may be injected between substrates provided with nonlinear active elements, such as thin film transistors or diodes formed on each pixel, to form an active matrix liquid crystal display device.

Abstract: An anti-ferroelectric liquid crystal compound of the following general formula (1), and an anti-ferroelectric liquid crystal composition containing it, ##STR1## wherein R is a linear alkyl group, A is --O-- or --COO--, m is an integer of 5 or greater, n is an integer of 1 to 3, each of X and Y is independently a hydrogen atom or a fluorine atom, and C* is asymmetric carbon.

Abstract: A phenyl ester compound of the following general formula (1), ##STR1## wherein m is an integer of 3 to 8, n is an integer of 3 to 11, both of X.sup.1 and X.sup.2 are hydrogen atoms, or one of X.sup.1 and X.sup.2 is a fluorine atom and the other is a hydrogen atom, and A is a hydrogen atom or --CH.sub.3 ; and an anti-ferroelectric liquid crystal composition containing the above phenyl ester compound and a specific anti-ferroelectric liquid crystal compound or a specific liquid crystal compound having ferrielectric-phase.

Abstract: A two-rings-containing phenyl ester compound of the following general formula (1), ##STR1## wherein R.sup.1 is a linear alkyl group having 5 to 12 carbon atoms, R.sup.2 is a linear alkyl group having 1 to 15 carbon atoms, X.sup.1 and X.sup.2 are both hydrogen atoms or one of X.sup.1 and X.sup.2 is a fluorine atom and the other is a hydrogen atom, Y.sup.1 and Y.sup.2 are both hydrogen atoms or one of Y.sup.1 and Y.sup.2 is a fluorine atom and the other is a hydrogen atom, and A.sup.1 is a hydrogen atom, --CH.sub.3 or --CF.sub.3, provided that when A.sup.1 is a hydrogen atom or --CH.sub.3, p is 0 and that when A.sup.1 is --CF.sub.3, p is t and q is an integer of 5 to 8, and an anti-ferroelectric liquid crystal composition containing at least one of two-rings-containing phenyl ester compounds of the above general formula (1) in claim 1 and either an anti-ferroelectric liquid crystal compound or a mixture of anti-ferroelectric liquid crystal compounds.

Abstract: Anti-ferroelectric liquid crystal substances which are represented by the formula (1): ##STR1## wherein R is a straight chain alkyl group having 6 to 10 carbon atoms,X is hydrogen or fluorine atom,Z is --CH.sub.3, --CF.sub.3 or --C.sub.2 H.sub.5, andC** stands for an asymmetric carbon atom, andl, m, and n are 0 or a certain integer depending on the specific kinds of X and Z,and the use of the substances for liquid crystal display devices.

Abstract: An anti-ferroelectric liquid crystal composition consisting essentially of an anti-ferroelectric liquid crystal (A) and a ferrielectric liquid crystal (B) shows a low threshold voltage so that the driving voltage can be decreased, and the composition can give a liquid crystal display device utilizing a fast response time or switching among tristabile states, a distinct threshold voltage characteristic and excellent memory performance.

Abstract: An antiferroelectric liquid crystal substance represented by the following general formula (1) ##STR1## wherein R represents a straight-chain alkyl group of 6-10 carbon atoms; X represents ##STR2## when X is ##STR3## Y is any of CH.sub.3, CF.sub.3 and C.sub.2 H.sub.5, L is 0 or an integer of 5 to 8, m is 0 or 1, and n is an integer of 1 to 10; when X is ##STR4## Y is any of CH.sub.3, CF.sub.3 and C.sub.2 H.sub.5, and (1) when Y is CH.sub.3, L is 0 or an integer of 5 to 8, m is 0 or 1, and n is an integer of 1 to 10, (2) when Y is CF.sub.3, L is an integer of 5 to 8, m is 1, and n is an integer of 1 to 10 and (3) when Y is C.sub.2 H.sub.5, L is 0, m is 0, and n is an integer of 4-10.

Abstract: A liquid crystal compound represented by formula (I) ##STR1## wherein R denotes a linear alkyl group having 6 to 14 carbon atoms, X denotes a single bond or an oxygen atom, K and L are independently 1 or 2, n is an integer of 3 to 8, and C* denotes an asymmetric carbon atom.and a liquid crystal display device formed therefrom.

Abstract: A liquid crystal compound represented by formula (I), ##STR1## wherein A represents --C.sub.3 H.sub.7, --C.sub.4 H.sub.9 or --C.sub.8 H.sub.17 ; when A is --C.sub.3 H.sub.7, m is an integer of 8, 10, 12 or 14; and when A is --C.sub.4 H.sub.9 or --C.sub.8 H.sub.17, m is an integer of 7 to 14,said compound having an antiferroelectric phase.

Abstract: A method for driving an antiferroelectric liquid crystal cell suitable for a simple-matrix display, "utilizing" third state .fwdarw.uniform state and "uniform state.fwdarw.third state" switchings, in which the uniform state to third state switching is done within a memory time of uniform to third state switching. The uniform states are employed as the light and dark states.

Abstract: An antiferroelectric liquid crystal compound which is a compound represented by ##STR1## wherein R denotes a linear aliphatic alkyl group having 6 to 14 carbon atoms; A denotes a single bond or an oxygen atom; X and Y independently denote a hydrogen atom or a fluorine atom but they are not hydrogen atoms at the same time; h and i are independently 1 or 2; m is an integer of 3 to 10; Z denotes CH.sub.3, C.sub.2 H.sub.5 or CF.sub.3 ; k is 0 or an integer of 5 to 8; l is 0 or 1; n is an integer of 1 to 6; W denotes CH.sub.3 or CF.sub.3 ; when W is CH.sub.3, p and q are both 0 and r is 8; when W is CF.sub.3, p is 5 to 8, q is 1 and r is 1 to 4; and C* denotes an asymmetric carbon atom,and a liquid crystal display device using same.

Abstract: Antiferroelectric liquid crystal composition comprising at least one of antiferroelectric liquid crystal substances, and at least one of optically active substances.

Abstract: A novel anti-ferroelectric liquid crystal of the formula (I), ##STR1## wherein: is an integer of 3 to 8,each of X and Y is independently a hydrogen atom or a fluorine atom,Z is --CF.sub.3, --CH.sub.3 or --C.sub.2 H.sub.5,q is 0 or 5,m is 0 or 1,n is an integer of 2 to 8, andC* is an asymmetric carbon, provided that when m is 0, q is 0 and n is an integer of 4 to 8 and that when m is 1, q is 5 and z is --CF.sub.3,and use of tile above liquid crystal as a liquid crystal display device.