Abstract: The present invention is to provide a process for producing dicyanonorbornane characterized by causing hydrogen cyanide to undergo addition reaction with cyanonorbornene (bicyclo[2.2.1]-5-heptene-2-carbonitrile) in the presence of a zerovalent nickel complex catalyst which is produced by using a phosphite represented by P(x)(y)(z) (wherein P is a phosphorus atom, and x, y and z are each OR, where R represents an aryl group having not more than 18 carbon atoms) as a ligand to reduce a nickel halide with at least one metal selected among zinc, cadmium, beryllium, aluminum, iron and cobalt, wherein the phosphite is one which has a phosphate content of 1.0 weight % or lower based on the whole phosphite.

Abstract: An isocyanate has been widely used as a starting material for the production of a polyurethane material, a polyisocyanurate material or the like which is suitably applicable to the field of optical materials. Disclosed is a process for producing an isocyanate which includes a step for producing the isocyanate in the form of a hydrochloride with improved productivity. A process for producing a linear or cyclic aliphatic isocyanate comprising the step of reacting a linear or cyclic aliphatic amine with hydrogen chloride to yield a hydrochloride of the linear or cyclic aliphatic amine, the step being performed under a pressure higher by 0.01 MPa or more than the atmospheric pressure.

Abstract: Pentaerythritol which contains none of the alkali metals and the alkaline earth metals or which contains at least one of these in a total amount of 1.0 weight % or smaller is reacted with a mercaptocarboxylic acid to produce a pentaerythritol mercaptocarboxylic acid ester.

Abstract: A process for producing pentaerythritol mercaptocarboxylic ester by reacting pentaerythritol with a mercaptocarboxylic acid having a content of thioester formed by condensation of two molecules of the acid of 5% or below (in terms of area percentage) as determined by the high-performance liquid chromatography in the case of the total area of the mercaptocarboxylic acid and thioester formed by intermolecular condensation of the acid is taken as 100%.

Abstract: Pentaerythritol which contains none of the alkali metals and the alkaline earth metals or which contains at least one of these in a total amount of 1.0 weight % or smaller is reacted with a mercaptocarboxylic acid to produce a pentaerythritol mercaptocarboxylic acid ester.

Abstract: The present invention is to provide a process for producing dicyanonorbornane characterized by causing hydrogen cyanide to undergo addition reaction with cyanonorbornene (bicyclo[2.2.1]-5-heptene-2-carbonitrile) in the presence of a zerovalent nickel complex catalyst which is produced by using a phosphite represented by P(x)(y)(z) (wherein P is a phosphorus atom, and x, y and z are each OR, where R represents an aryl group having not more than 18 carbon atoms) as a ligand to reduce a nickel halide with at least one metal selected among zinc, cadmium, beryllium, aluminum, iron and cobalt, wherein the phosphite is one which has a phosphate content of 1.0 weight % or lower based on the whole phosphite.

Abstract: An isocyanate has been widely used as a starting material for the production of a polyurethane material, a polyisocyanurate material or the like which is suitably applicable to the field of optical materials. Disclosed is a process for producing an isocyanate which includes a step for producing the isocyanate in the form of a hydrochloride with improved productivity. A process for producing a linear or cyclic aliphatic isocyanate comprising the step of reacting a linear or cyclic aliphatic amine with hydrogen chloride to yield a hydrochloride of the linear or cyclic aliphatic amine, the step being performed under a pressure higher by 0.01 MPa or more than the atmospheric pressure.

Abstract: The present invention provides a hydrogen sensor including a concentration cell holding a solid electrolyte having proton conductivity. The solid electrolyte is mainly formed of &agr; alumina in which oxide of alkaline earth metal is doped. The hydrogen sensor can measure a hydrogen concentration of measuring objects. For example, it is possible to measure a hydrogen concentration of high temperature gas or molten metal such as copper alloy, cast iron, carbon steel, and alloy steel.

Abstract: A metal melt is used as a measuring electrode while a pure form of a particular metal component to be measured or an alloy containing it is used as a standard electrode. The active substance to come in contact with the standard electrode includes at least one halide of an alkali halide and an alkaline earth halide, both having ion conductivity, and a halide of the particular metal component, any one of such halides consisting of a solid phase and a liquid phase. This active substance is provided such that it can come into contact with the metal melt and is used as an electrolyte as well. It is thus possible to provide a continuous detection of the concentration of the particular component in the molten metal to be measured.