Abstract: To provide a dichloromethane purification method which can reduce the amount of stabilizers present in dichloromethane and is feasible in industry by a simple operation, a dichloromethane purification method includes bringing dichloromethane containing at least one stabilizer selected from the group consisting of 2-methyl-2-butene, hydroquinone and resorcinol into contact in a liquid phase state with a zeolite having an average pore size of 3 to 11 ? and thereby reducing the amount of the stabilizer.

Abstract: The present invention relates to a method for producing monosilane and tetraalkoxysilane comprising subjecting alkoxysilane represented by formula (1) HnSi(OR)4-n??(1) wherein R represents alkyl group having 1 to 6 carbon atoms and n represents an integer of from 1 to 3, to disproportionation reaction in a gaseous phase in the presence of an inorganic phosphate or a catalyst having a specific chemical structure based on a heteropolyacid salt structure. In the production method of the present invention, separation from the solvent can be carried out easily, the reaction proceeds quickly and the conversion rate of the starting materials is high.

Abstract: An efficient process is provided in which sulfur is reacted with carbon monoxide in a liquid phase to produce carbonyl sulfide. In the presence of a base catalyst, carbon monoxide is continuously introduced into a reactor in which a liquid reaction mixture obtained by dissolving or suspending sulfur in an organic solvent is held, and the sulfur is reacted with the carbon monoxide at a pressure of 0.2-3.0 MPa and a temperature of 40-120° C. to yield carbonyl sulfide. The gaseous-phase part is withdrawn from the reactor, and the withdrawn gaseous-phase part is cooled with a cooler to condense the carbonyl sulfide contained in the gaseous-phase part. The condensed carbonyl sulfide is continuously withdrawn, and the gas that has not been condensed with the cooler is returned to the reactor. Thus, carbonyl sulfide is continuously produced.

Abstract: The present invention relates to a method for producing monosilane and tetraalkoxysilane comprising subjecting alkoxysilane represented by formula (1) HnSi(OR)4-n??(1) wherein R represents alkyl group having 1 to 6 carbon atoms and n represents an integer of from 1 to 3, to disproportionation reaction in a gaseous phase in the presence of an inorganic phosphate or a catalyst having a specific chemical structure based on a heteropolyacid salt structure. In the production method of the present invention, separation from the solvent can be carried out easily, the reaction proceeds quickly and the conversion rate of the starting materials is high.

Abstract: The present invention relates to a method for producing monosilane and tetraalkoxysilane comprising subjecting alkoxysilane represented by formula (1) HnSi(OR)4?n??(1) wherein R represents alkyl group having 1 to 6 carbon atoms and n represents an integer of from 1 to 3, to disproportionation reaction in a gaseous phase in the presence of an inorganic phosphate or a catalyst having a specific chemical structure based on a heteropolyacid salt structure. In the production method of the present invention, separation from the solvent can be carried out easily, the reaction proceeds quickly and the conversion rate of the starting materials is high.

Abstract: The present invention relates to method for producing monosilane and tetraalkoxysilane comprising subjecting alkoxysilane represented by formula (1) HnSi(OR) 4-n??(1) wherein R represents alkyl group having 1 to 6 carbon atoms and n represents an integer of from 1 to 3, to dismutation reaction in a gaseous phase in the presence of a catalyst containing an alkali metal fluoride and a catalyst activator. The method can solve problems in a method for producing monosilane and tetraalkoxysilane by dismutation reaction of alkoxysilane in a liquid phase: i.e. problems such that separation from the solvent is difficult and that the reaction is too slow and not suitable for industrial production.

Abstract: There is provided a fluorine-containing compound purification method for obtaining a high-purity fluorine-containing compound by efficiently separating and removing hydrogen chloride from a fluorine-containing compound that contains hydrogen chloride, i.e., from a crude fluorine-containing compound. The fluorine-containing compound purification method of the present invention comprises the following steps (1) and (2) in this order: step (1): a step of adding dimethyl ether to a crude fluorine-containing compound that contains a fluorine-containing compound and hydrogen chloride in a molar ratio (dimethyl ether (mol)/hydrogen chloride (mol)) of dimethyl ether to hydrogen chloride being 1.3 or more to prepare a mixture (1) of the crude fluorine-containing compound and dimethyl ether; and step (2): a step of separating and removing a mixture (2) of hydrogen chloride and dimethyl ether from the mixture (1).

Abstract: An object of the invention is to provide efficient, simple and inexpensive processes for the production of carbonyl difluoride, which is an attractive and important compound as a semiconductor etching gas or a semiconductor cleaning gas. A process for producing carbonyl difluoride of the invention includes a step of reacting phosgene and hydrogen fluoride in a gas phase in the presence of a fluorination catalyst to produce carbonyl difluoride and hydrogen chloride, and a step of mixing a mixture containing the carbonyl difluoride and the hydrogen chloride with an organic solvent that is azeotropic with hydrogen chloride but zeotropic with carbonyl difluoride, and distilling the resultant mixture to separate the carbonyl difluoride.

Abstract: An efficient process is provided in which sulfur is reacted with carbon monoxide in a liquid phase to produce carbonyl sulfide. In the presence of a base catalyst, carbon monoxide is continuously introduced into a reactor in which a liquid reaction mixture obtained by dissolving or suspending sulfur in an organic solvent is held, and the sulfur is reacted with the carbon monoxide at a pressure of 0.2-3.0 MPa and a temperature of 40-120° C. to yield carbonyl sulfide. The gaseous-phase part is withdrawn from the reactor, and the withdrawn gaseous-phase part is cooled with a cooler to condense the carbonyl sulfide contained in the gaseous-phase part. The condensed carbonyl sulfide is continuously withdrawn, and the gas that has not been condensed with the cooler is returned to the reactor. Thus, carbonyl sulfide is continuously produced.

Abstract: It is an object of the present invention to provide a process for producing 1,2,3,4 -tetrachlorohexafluorobutane industrially inexpensively and efficiently by utilizing expensive fluorine gas efficiently and to provide a process which is capable of stably producing 1,2,3,4 -tetrachlorohexafluorobutane and in which, by carrying out fluorination reaction at a low temperature, side reactions such as formation of a low-boiling substance due to cleavage of C—C bonds and formation of an excess fluoride are difficult to occur. The process for producing 1,2,3,4-tetrachlorohexafluorobutane of the present invention is characterized in that it includes feeding fluorine gas to 1,2,3,4-tetrachlorobutane using plural reactors in the presence of a solvent and in the absence of a catalyst to allow the 1,2,3,4-tetrachlorobutane and the fluorine gas to react with each other, wherein a part or all of unreacted fluorine gas discharged from one reactor is introduced into a reactor different from said one reactor.

Abstract: The present invention provides a process for producing 1,2,3,4-tetrachlorohexafluorobutane having a high purity at a low cost industrially and efficiently. The process for producing 1,2,3,4-tetrachlorohexafluorobutane according to the present invention comprises a step of allowing 1,2,3,4-tetrachlorobutane to react with a fluorine gas to prepare a reaction product containing 1,2,3,4-tetrachlorohexafluorobutane and hydrogen-containing compounds as an impurity, and a step of introducing the reaction product into single or plural distillation columns and distilling to separate the hydrogen-containing compounds from the reaction product and thereby preparing purified 1,2,3,4-tetrachlorohexafluorobutane wherein the at least one of distillation columns has a theoretical plate number of 15 or more.

Abstract: The production process for 1,2,3,4-tetrachlorohexafluorobutane of the present invention is characterized in that 1,2,3,4-tetrachlorobutane is reacted with fluorine in the presence of a solvent containing hydrogen fluoride. The 1,2,3,4-tetrachlorobutane may be obtained by chlorination of 3,4-dichlorobutene-1. Further, the present invention provides as well a process of refining 1,2,3,4-tetrachlorohexafluorobutane obtained in the manner described above. According to the present invention, 1,2,3,4-tetrachlorohexafluorobutane which is useful, for example, as a synthetic raw material for hexafluoro-1,3-butadiene used as an etching gas for semiconductors can industrially efficiently be produced by using 1,2,3,4-tetrachlorobutane which is a by-product of chloroprene and which has so far been disposed.

Abstract: The present invention relates to a method for producing monosilane and tetraalkoxysilane comprising subjecting alkoxysilane represented by formula (1) HnSi(OR)4?n??(1) wherein R represents alkyl group having 1 to 6 carbon atoms and n represents an integer of from 1 to 3, to disproportionation reaction in a gaseous phase in the presence of an inorganic phosphate or a catalyst having a specific chemical structure based on a heteropolyacid salt structure. In the production method of the present invention, separation from the solvent can be carried out easily, the reaction proceeds quickly and the conversion rate of the starting materials is high.

Abstract: The production process of the present invention for a chlorine-containing fluorine-containing compound is characterized in that a reaction of adding chlorine atoms to a carbon-carbon unsaturated bond of a hydrogen-containing compound having a carbon-carbon unsaturated bond is carried out under the presence of a fluorine gas. The hydrogen-containing compound having a carbon-carbon unsaturated bond may be 3,4-dichlorobutene-1. Further, the present invention provides a process for producing efficiently and economically 1,2,3,4 -tetrachlorohexafluorobutane from 3,4-dichlorobutene-1 described above. According to the present invention, chlorination and fluorination of the hydrogen-containing compound having a carbon-carbon unsaturated bond are carried out in a single step, and therefore a chlorine-containing fluorine-containing compound can be more economically produced at a higher yield than in a conventional process in which two reactions are individually carried out.

Abstract: There is provided a fluorine-containing compound purification method for obtaining a high-purity fluorine-containing compound by efficiently separating and removing hydrogen chloride from a fluorine-containing compound that contains hydrogen chloride, i.e., from a crude fluorine-containing compound. The fluorine-containing compound purification method of the present invention comprises the following steps (1) and (2) in this order: step (1): a step of adding dimethyl ether to a crude fluorine-containing compound that contains a fluorine-containing compound and hydrogen chloride in a molar ratio (dimethyl ether (mol)/hydrogen chloride (mol)) of dimethyl ether to hydrogen chloride being 1.3 or more to prepare a mixture (1) of the crude fluorine-containing compound and dimethyl ether; and step (2): a step of separating and removing a mixture (2) of hydrogen chloride and dimethyl ether from the mixture (1).

Abstract: The process for producing a fluorine-containing compound such as 1,2,3,4-tetrachlorohexafluorobutane of the present invention is characterized in that a halogenated hydrocarbon compound such as 1,2,3,4-tetrachlorobutane is brought into contact with fluorine gas in a liquid phase or in a solid-liquid coexistence state in the absence of a solvent and a catalyst. According to the present invention, a fluorine-containing compound is readily produced from a halogenated hydrocarbon compound using neither a reaction solvent nor a reaction catalyst.

Abstract: The process for recovering pentafluoroethane of the invention includes bringing a mixed gas containing pentafluoroethane and a non-condensable gas into contact with a chlorinated solvent, and allowing the chlorinated solvent to absorb pentafluoroethane contained in the mixed gas. The process for the production of pentafluoroethane of the invention uses the recovering process.

Abstract: The present invention relates to method for producing monosilane and tetraalkoxysilane comprising subjecting alkoxysilane represented by formula (1) HnSi(OR) 4-n??(1) wherein R represents alkyl group having 1 to 6 carbon atoms and n represents an integer of from 1 to 3, to dismutation reaction in a gaseous phase in the presence of a catalyst containing an alkali metal fluoride and a catalyst activator. The method can solve problems in a method for producing monosilane and tetraalkoxysilane by dismutation reaction of alkoxysilane in a liquid phase: i.e. problems such that separation from the solvent is difficult and that the reaction is too slow and not suitable for industrial production.

Abstract: An object of the invention is to provide efficient, simple and inexpensive processes for the production of carbonyl difluoride, which is an attractive and important compound as a semiconductor etching gas or a semiconductor cleaning gas. A process for producing carbonyl difluoride of the invention includes a step of reacting phosgene and hydrogen fluoride in a gas phase in the presence of a fluorination catalyst to produce carbonyl difluoride and hydrogen chloride, and a step of mixing a mixture containing the carbonyl difluoride and the hydrogen chloride with an organic solvent that is azeotropic with hydrogen chloride but zeotropic with carbonyl difluoride, and distilling the resultant mixture to separate the carbonyl difluoride.

Abstract: The present invention provides a process for producing 1,2,3,4-tetrachlorohexafluorobutane having a high purity at a low cost industrially and efficiently. The process for producing 1,2,3,4-tetrachlorohexafluorobutane according to the present invention comprises a step of allowing 1,2,3,4-tetrachlorobutane to react with a fluorine gas to prepare a reaction product containing 1,2,3,4-tetrachlorohexafluorobutane and hydrogen-containing compounds as an impurity, and a step of introducing the reaction product into single or plural distillation columns and distilling to separate the hydrogen-containing compounds from the reaction product and thereby preparing purified 1,2,3,4-tetrachlorohexafluorobutane wherein the at least one of distillation columns has a theoretical plate number of 15 or more.