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 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 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 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 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 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.

Abstract: A novel liquid crystal compound useful as a component of liquid crystal compositions and a liquid crystal composition containing the same are provided, which compound is a phenoxypropanol ester derivative expressed by the formula ##STR1## wherein R.sup.1 and R.sup.2 each represent an alkyl group or an alkoxy group each of 1 to 15 carbon atoms, F atom, Cl atom or CN group, but either one of R.sup.1 and R.sup.

Abstract: A novel liquid crystal compound which is superior in compatibility with other liquid crystal compounds or liquid crystal compositions, chemically stable, and when added to liquid crystal compositions, can raise the clearing point thereof almost without increasing the viscosity and enhance .DELTA..epsilon. and .DELTA.n thereof, and a liquid crystal composition containing the same are provided, which compound is expressed by the formula ##STR1## wherein R represents an alkyl group or an alkoxy group each of 1 to 10 carbon atoms; Y represents F, Cl or H; and Z represents F, Cl, cyano group or an alkyl group or an alkoxy group each of 1 to 10 carbon atoms.

Abstract: A novel 1,4-dipyrimidinylbenzene derivative which is useful as a component constituting a liquid crystal composition which is superior in properties and also physically and chemically stable, as a material for liquid crystal display elements, and a liquid crystal composition containing the same are provided, which derivative is expressed by the formula ##STR1## wherein X represents an alkyl group or an alkoxy group each of 1 to 10 carbon atoms, methylthio group or cyano group and Y represents an alkyl group or an alkoxy group each of 1 to 10 carbon atoms.

Abstract: A novel compound which exhibits superior effectiveness particularly in reducing the driving voltage of liquid crystal display elements, and a liquid crystal composition containing the same are provided, which compound is a 5-alkyl-2-(3,4-difluorophenyl)pyrimidine expressed by the formula ##STR1## wherein m represents an integer of 1 to 8.

Abstract: Ester compounds having a pyrimidine ring, using as their raw material, substituted pyrimidinols in place of expensive p-substituted phenols, and also useful as a material for liquid crystal display elements are provided which esters are expressed by the general formula ##STR1## wherein R represents an alkyl or alkoxy group of 1 to 10 carbon atoms; X represents a halogen atom of F, Cl or Br, cyano group or an alkyl or alkoxy group of 1 to 10 carbon atoms; ##STR2## represents ##STR3## and n is 0 or 1.

Abstract: A novel bipyrimidinyl derivative which is superior in practical properties and useful as a high temperature liquid crystal component constituting a physically and chemically stable liquid crystal composition is provided, which bipyrimidinyl derivative is a 2,5'-disubstituted-5,2'-bipyrimidinyl expressed by the formula ##STR1## wherein ##STR2## X represents a halogen atom of F, Cl or Br or cyano group or an alkyl group or an alkoxy group each having 1 to 10 carbon atoms and R represents an alkyl group or an alkoxy group each having 1 to 10 carbon atoms.

Abstract: Novel liquid crystal compounds having superior properties and liquid crystal compositions containing the same are provided, which compounds are expressed by the general formula ##STR1## wherein R.sub.1 represents an alkyl group or an alkoxy group, each having 1 to 10 carbon atoms and R.sub.2 represents cyano group or an alkyl group having 1 to 10 carbon atoms.

Abstract: Novel compounds capable of improving various characteristics required for liquid crystal compositions when added to liquid crystal substances, and liquid crystal compositions containing the same are provided, which novel compounds are halogenopyrimidine derivatives expressed by the general formula ##STR1## wherein R.sup.1 represents an alkyl group of 1 to 10 carbon atoms, R.sup.2 represents a halogen atom of F, Cl of Br and l represents 1 or 2.

Abstract: A process for the production of dinitrophenyl ethers having the general formula [III]: ##STR1## wherein, one of R.sub.1 and R.sub.2 is a nitro radical, and the other is a hydrogen atom or a straight-chain, branched-chain or cyclic, saturated or unsaturated hydrocarbon radical containing from 1 to 10 carbon atoms, and R.sub.3 is a radical selected from the group consisting of (i) a straight-chain, branched-chain or cyclic, saturated or unsaturated hydrocarbon radical containing from 2 to 10 carbon atoms, (ii) a straight-chain hydrocarbon radical having one phenyl group as a substituent and containing from 1 to 5 carbon atoms, (iii) a phenyl radical, and (iv) a phenyl radical with one or more than one substituents selected from the group consisting of a nitro group, a halogen group, a saturated or unsaturated hydrocarbon group containing from 1 to 5 carbon atoms and an alkoxy group containing from 1 to 4 carbon atoms, by reacting a compound represented by the formula [I]: ##STR2## wherein, R.sub.1 and R.sub.

Abstract: A method for producing semiconductor devices having a substrate, element fabrication areas formed in the substrate and isolation areas surrounding the element fabrication areas. The method comprises forming a thermal strain absorbing layer on the top surface of the element fabrication areas, forming at least one groove in an area which is to become the isolation areas, inlaying an insulator in the at least one groove, and annealing the insulator to make the density thereof uniform.

Abstract: A method and an apparatus for plasma etching semiconductor materials by providing an intermediate electrode between the electrodes in a parallel state type plasma etching apparatus, moving the intermediate electrode by a drive mechanism, and continuously changing from a condition of high input power and high self-bias voltage to a condition of low input power and low self-bias voltage while varying the distance between the intermediate electrode and the first electrode and the RF power, thereby to remove damage or deposits that may have been formed on the surface when the semiconductor material was being subjected to processing.

Abstract: A method for purifying raw acetic acid containing formaldehyde is provided wherein raw acetic acid is heat-treated at a temperature of about its boiling point or higher, in advance of the conventional distillation for removing a lower boiling fraction, and the acetic acid thus heat-treated is distilled to remove the lower boiling fraction, whereby the content of formaldehyde can be reduced down to 30 ppm or lower.