The invention relates to a method for the preparation of bis(fluorosulfonyl)-imide and its derivatives at elevated temperature.

The invention relates to a method for the preparation of bis(fluorosulfonyl)-imide and its derivatives at elevated temperature.

The objective of the present invention is to provide a clear conductive material with less turbidity, methods for producing and purifying the conductive material, and a nonaqueous electrolyte solution and an antistatic agent which contain the conductive material. The conductive material of the present invention comprises a fluorosulfonylimide salt represented by the following formula (1):

##STR00001##

wherein X is F of a C.sub.1-6 fluoroalkyl group,
and at least one organic solvent selected from the group consisting of a carbonate solvent, an ester solvent, a ketone solvent and an alcohol solvent, wherein a concentration of the fluorosulfonylimide salt is 0.1 mol/L or more, and a turbidity is 50 NTU/mol-LiFSI or less; and the production method of the present invention comprises the step of filtering a solution comprising the fluorosulfonylimide salt and the organic solvent by using a filter medium comprising the specific material.

The objective of the present invention is to provide a clear conductive material with less turbidity, methods for producing and purifying the conductive material, and a nonaqueous electrolyte solution and an antistatic agent which contain the conductive material. The conductive material of the present invention comprises a fluorosulfonylimide salt represented by the following formula (1):

##STR00001##

wherein X is F of a C.sub.1-6 fluoroalkyl group,
and at least one organic solvent selected from the group consisting of a carbonate solvent, an ester solvent, a ketone solvent and an alcohol solvent, wherein a concentration of the fluorosulfonylimide salt is 0.1 mol/L or more, and a turbidity is 50 NTU/mol-LiFSI or less; and the production method of the present invention comprises the step of filtering a solution comprising the fluorosulfonylimide salt and the organic solvent by using a filter medium comprising the specific material.

The present invention provides a method for producing a disulfonylamine alkali metal salt, including a step of subjecting a disulfonylamine onium salt represented by formula [I] (wherein each of R.sup.1 and R.sup.2 independently represents a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms, provided that at least one of R.sup.1 and R.sup.2 represents a fluorine atom, and each of R.sup.3, R.sup.4, R.sup.5 and R.sup.6 independently represents a hydrogen atom or the like) to a cation exchange reaction in an organic solvent, thereby producing a disulfonylamine alkali metal salt represented by formula [II] (wherein M.sup.+ represents an alkali metal cation, and R.sup.1 and R.sup.2 are as defined in formula [I]), and a step of filtering the organic solvent solution containing the disulfonylamine alkali metal salt through a filter having a particle retention size of 0.1 to 10 m to obtain a filtrate. ##STR00001##

The present invention provides a method for producing a disulfonylamine alkali metal salt, including a step of subjecting a disulfonylamine onium salt represented by formula [I] (wherein each of R.sup.1 and R.sup.2 independently represents a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms, provided that at least one of R.sup.1 and R.sup.2 represents a fluorine atom, and each of R.sup.3, R.sup.4, R.sup.5 and R.sup.6 independently represents a hydrogen atom or the like) to a cation exchange reaction in an organic solvent, thereby producing a disulfonylamine alkali metal salt represented by formula [II] (wherein M.sup.+ represents an alkali metal cation, and R.sup.1 and R.sup.2 are as defined in formula [I]), and a step of filtering the organic solvent solution containing the disulfonylamine alkali metal salt through a filter having a particle retention size of 0.1 to 10 m to obtain a filtrate. ##STR00001##

The present invention provides a method for producing a fluorisulfonylimide salt, which enables reducing the impurity content and continuous operation for a long time, and a fluorosulfonyl imide salt. The fluorosulfonyl imide salt of the present invention has a K content of 10,000 ppm or less. The method for producing a fluorosulfonyl imide salt of the present invention is that after a fluorination reaction of chlorosulfonyl imde or a salt thereof, the reaction solution is brought into contact with an aqueous alkaline solution so as to remove impurities. The fluorosulfonyl imide salt of the present invention, in which various impirities are reduced to extremely low levels, is useful as an electrolyte used in a lithium secondary battery, a capacitor or the like, an ionic liquid, or an intermediate for a sulfonyl imide salt, and the like. It is expected that use of the fluorosulfonyl imide salt of the present invention as an electrolyte leads to a high-performance electrochemical device.

The present invention provides a method for producing a fluorisulfonylimide salt, which enables reducing the impurity content and continuous operation for a long time, and a fluorosulfonyl imide salt. The fluorosulfonyl imide salt of the present invention has a K content of 10,000 ppm or less. The method for producing a fluorosulfonyl imide salt of the present invention is that after a fluorination reaction of chlorosulfonyl imde or a salt thereof, the reaction solution is brought into contact with an aqueous alkaline solution so as to remove impurities. The fluorosulfonyl imide salt of the present invention, in which various impirities are reduced to extremely low levels, is useful as an electrolyte used in a lithium secondary battery, a capacitor or the like, an ionic liquid, or an intermediate for a sulfonyl imide salt, and the like. It is expected that use of the fluorosulfonyl imide salt of the present invention as an electrolyte leads to a high-performance electrochemical device.

The present invention relates to a process for preparing a fluorosulfony limide salt. More specifically. the present invention relates to a process for preparing lithium bis(fluorosulfonyl)imide (LiFSI).

The present invention relates to a process for preparing a fluorosulfony limide salt. More specifically. the present invention relates to a process for preparing lithium bis(fluorosulfonyl)imide (LiFSI).