Abstract: A polyamic acid is herein disclosed which contains a structural unit represented by the formula ?2a! ##STR1## wherein m is an integer of 1 to 20; n is an integer of 1 to 2; and R.sup.2 is an alkyl group or an alkoxy group having 1 to 20 carbon atoms. Furthermore, a polyamic acid composition is also disclosed which comprises the polyamic acid containing the structural unit represented by the formula ?2a! and another polyamic acid containing a structural unit other than mentioned above. By heating the polyamic acid or the polyamic acid composition at a low temperature for a short time, a liquid crystal alignment film can be obtained which comprises a polyimide or a polyimide composition.

Abstract: The UV crosslinking compound of the present invention is characterized in having the following chemical formula, and has high photosensitivity. Accordingly, the crosslinking reaction can be accomplished within a short period of time. Thus, if this compound is employed in the alignment film for a LCD component, it becomes possible to carry out a sufficient alignment treatment with UV irradiation over a short period of time. Accordingly, production time can be shortened and production costs reduced. ##STR1## wherein, n is an integer, and X is an atom selected from among F, Cl, Br, I and CN.

Abstract: A polyamic acid is herein disclosed which contains a structural unit represented by the formula ?2a! ##STR1## wherein m is an integer of 1 to 20; n is an integer of 1 to 2; and R.sup.2 is an alkyl group or an alkoxy group having 1 to 20 carbon atoms. Furthermore, a polyamic acid composition is also disclosed which comprises the polyamic acid containing the structural unit represented by the formula ?2a! and another polyamic acid containing a structural unit other than mentioned above. By heating the polyamic acid or the polyamic acid composition at a low temperature for a short time, a liquid crystal alignment film can be obtained therefore.

Abstract: A novel cyclohexane derivative having a good stability, a low viscosity and a large dielectric aniostropy value and a liquid crystal composition containing the same are provided, which derivative is expressed by the formula ##STR1## wherein R represents an alkyl group of 1 to 10 carbon atoms; A represents hydrogen, halogen or cyano group; l represents 1 or 2; and m represents 0 or 1.

Abstract: A novel fluorophenylcyclohexane derivative useful as a component of liquid crystal compositions used for liquid crystal display elements, and a liquid crystal composition containing the same are provided, which fluorophenylcyclohexane derivative is expressed by the formula ##STR1## wherein R.sup.1 represents an alkyl group of 1 to 10 carbon atoms; R.sup.2 represents an alkyl group or an alkoxy group each of 1 to 10 carbon atoms; a.sup.1 represents a hydrogen atom and a.sup.2 represents a fluorine atom; A represents a 1,4-phenylene group; l and m each represent an integer of 0, 1 or 2 or 3; and a value of (l+m) is 2 or 3.

Abstract: A novel liquid crystal compound suitable to use as a component of liquid crystal dielectrics and a liquid crystal composition containing the same are provided, which compound is a dihalogeno-aromatic compound expressed by the formula ##STR1## wherein R is alkyl or alkoxy of 1.about.12 C or alkoxymethyl of 2.about.

Abstract: A process for directly producing liquid crystalline polymers from cyclohexanedicarboxylic acids and aromatic diols is provided. These raw materials can be converted into polyesters capable of finishing into fibers, films, etc., using the combination of thionyl chloride and pyridine as a condensing agent. In the present invention, aromatic oxycarboxylic acids can be used in combination in an optional proportion, in addition to the above two raw materials.

Abstract: A novel cyclohexane derivative having a good stability, a low viscosity and a large dielectric aniostropy value and a liquid crystal composition containing the same are provided, which derivative is expressed by the formula ##STR1## wherein R represents an alkyl group of 1 to 10 carbon atoms; A represents hydrogen, halogen or cyano group; l represents 1 or 2; and m represents 0 or 1.

Abstract: A novel ester compound which, when added to a liqud crystal composition, can raise its nematic phase-isotropic liquid phase transition point without raising its viscosity, and a liquid crystal composition containing the same are provided, which ester compound is expressed by the formula ##STR1## wherein R.sub.1 and R.sub.

Abstract: Novel compounds which, when used as a components of liquid crystal compositions, have good compatibility with other components and also have large values of dielectric anisotropy and optical anisotropy, and liquid crystal compositions containing the same are provided, which compounds are 4'-cyano-3'-halogenophenyl 4-(5-substituted-pyrimidin-2-yl)benzoate expressed by the formula ##STR1## wherein R represents an alkyl group of 1 to 10 carbon atoms or --(CH.sub.2).sub.m --O--(CH.sub.2).sub.p --CH.sub.3 wherein m and p each represent an integer of 0 to 8 and m+p.ltoreq.8, and X represents a halogen atom.

Abstract: A novel liquid crystal compound having a large positive dielectric anisotropy value and when added to a liquid crystal composition, forming no deposit in the resulting composition at low temperatures, and a liquid crystal composition containing the same are provided, which compound is an alkoxyethoxybenzoic acid ester derivative expressed by the formula ##STR1## wherein R represents an alkyl group of 1 to 10 carbon atoms.

Abstract: New liquid-crystalline ester compounds which exhibit a liquid-crystalline phase within a broad temperature range and have a positive, dielectric anisotropy, and a liquid-crystalline composition comprising the same are provided which ester compounds are expressed by the general formula ##STR1## wherein R represents hydrogen atom or an alkyl group of 1 to 10 carbon atoms; ##STR2## each represent ##STR3## X represents ##STR4## Y represents hydrogen atom, F, Cl or CN; and Z represents F, Cl or CN.

Abstract: A novel ester compound exhibiting liquid crystal phases within a broad temperature range and having a low viscosity and a high compatibility with liquid crystal compounds, and a liquid crystal composition containing the same are provided, which ester compound is expressed by the formula ##STR1## wherein X represents F or Cl; Y and Z each represent H, F or Cl and when either one of Y or Z is H, the other is F or Cl and further when X is Cl, Y and Z are not both Cl; --A-- represents a member selected from the group consisting of ##STR2## and R represents an alkyl group or an alkoxy group each of 1 to 10 carbon atoms.

Abstract: A compound which, when used as a component of a liquid crystal composition, has an effectiveness of notably reducing the viscosity and the operating voltage of the resulting liquid crystal composition, and a liquid crystal composition containing the same are provided, which compound is a cyclohexane derivative expressed by the formula ##STR1## wherein R represents hydrogen atom or an alkyl group of 1 to 10 carbon atoms.

Abstract: A novel compound useful as a component of liquid crystal compositions, for lowering their melting point without lowering so much the clearing point in the mesomorphic range of the compositions, and a liquid crystal composition containing the same are provided, which compound is expressed by the general formula ##STR1## wherein R.sup.1 is alkyl or alkoxy each of 1-15 C; n is 1 or 2; and X is ##STR2## wherein R.sup.2 is alkyl or alkoxy each of 1-15 C, when n is 1, or F, Cl, CN, alkyl or alkoxy each of 1-15 C when n is 2.

Abstract: A novel pyridine derivative which, when added to liquid crystal substances, can improve various specific features required for the resulting liquid crystal compositions, and a liquid crystal composition containing the same are provided, which pyridine derivative is expressed by the formula ##STR1## wherein W represents H or F; X, F, Cl or alkyl or alkoxy of 1.about.10 C; ##STR2## n, 0 or 1; Y, CN or alkyl or alkoxy of 1.about.10 C; Z, F, Cl or H; and when Z is F or Cl, Y is limited to CN, excluding certain identified compounds.

Abstract: A novel pyrimidine derivative which, when used as a component of a liquid crystal composition, is useful for driving a liquid crystal cell containing the composition at low voltages, and a liquid crystal composition containing the same are provided, which pyrimidine derivative is expressed by the formula ##STR1## wherein n represents an integer of 0 or 1; R represents an alkyl or alkoxy group of 1 to 10 carbon atoms; and X.sub.1, X.sub.2 and X.sub.3 each represent hydrogen atom, F, Cl or Br as halogeno group, cyano group or trifluoromethyl group and at least one of X.sub.1, X.sub.2 and X.sub.3 is trifluoromethyl group.

Abstract: A compound which, when added as a component to other components, raises the N-I point of the resulting liquid crystal composition and nevertheless affords only a relatively small rise in viscosity of the composition, and a liquid crystal composition containing the same are provided, which compound is a 1-(trans-4'-alkylcyclohexyl)-2-4"-[trans-4"'-(trans-4""-alkylcyclohexyl)cy clohexylphenyl]ethane expressed by the formula ##STR1## wherein R.sup.1 and R.sup.2 each represent an alkyl group of 1 to 10 carbon atoms.

Abstract: A novel liquid crystal compound suitable to use as a component of liquid crystal dielectrics and a liquid crystal composition containing the same are provided, which compound is a dihalogeno-aromatic compound expressed by the formula ##STR1## wherein R represents an alkyl group or an alkoxy group, each of 1 to 12 carbon atoms, or an alkoxymethyl group of 2 to 12 carbon atoms.

Abstract: A novel liquid crystal ester compound which is useful as a component for TN type nematic liquid crystal composition, raising its nematic-isotropic liquid phase-isotropic liquid phase transition point without increasing its viscosity and a liquid crystal composition containing the same are provided, which ester compound is expressed by the formula ##STR1## wherein R.sup.1 represents an alkyl group or an alkoxy group each of 1 to 10 carbon atoms; ##STR2## represents ##STR3## Y represents -- COO--or --OCO--; any of ##STR4## n represents 0 or 1; and Z represents an alkyl group or an alkoxy group each of 1 to 10 carbon atoms, or a halogen atom of F, Cl or Br.