Central Glass Company, Limited

Hiroaki Sakaguchi

Minoru Aramaki

Tamio Nakamura

Shigenori Sakai

Yasushi Kita

Takashi Suenaga

Yoshiyuki Kobayashi

Hironari Takase

Keiji Sato

Meguru Oe

Takanori Hamana

Kenji Fujii

Kimitaka Okamoto

A method for producing an electrolyte solution for a lithium ion battery involving reacting a lithium halide selected from the group consisting of lithium fluoride, lithium chloride, lithium bromide, lithium iodide and a mixture of at least two of these, with phosphorus pentachloride and hydrogen fluoride in a nonaqueous organic solvent, thereby producing lithium hexafluorophosphate as an electrolyte of the electrolyte solution.

Method for producing electrolyte solution for lithium ion battery and battery using same

The invention relates to a method for producing a sulfonimide or its alkali metal salt. The method includes the steps of (a) reacting a precursory salt of the sulfonimide with a base contained in a basic aqueous solution, thereby producing a first aqueous solution containing the alkali metal salt and an amine; (b) removing the amine from the first aqueous solution to obtain a second aqueous solution containing the alkali metal salt; and (c) crystallizing the alkali metal salt in the second aqueous solution. The base is potassium hydroxide, sodium hydroxide or lithium hydroxide. The base is added to the second aqueous solution to generate the crystallization. The precursory salt is formed when the sulfonimide is reacted with a tertiary amine or a heterocyclic amine. The alkali metal salt is produced easily and economically in an industrial scale production with high purity and high yield.

Method for producing sulfonimide or its salt

The invention relates to a method of preparing a sulfonimide, a first salt thereof, or a second salt thereof. The method includes the step of: (a) reacting one or two sulfonyl fluorides with nonhydrous ammonia and an amine component which is one of a tertiary amine and a heterocyclic amine, so as to prepare the first salt. Alternatively, the method includes the step of: (a) reacting the sulfonyl fluoride with the amine component and a sulfonamide, so as to prepare the first salt. The method further optionally includes, after the step (a), the step of: (b) reacting, in an aqueous solution, the first salt with a metal compound, so as to prepare the second salt. The method still further optionally includes, after the step (a), the step of: (c) reacting the first salt with a strong acid so as to prepare the sulfonimide. Alternatively, the method further optionally includes, after the step (b), the step of: (d) reacting the second salt with a strong acid so as to prepare the sulfonimide. The sulfonimide, the first salt or the second salt is easily economically prepared in an industrial scale production with high purity and high yield.

Method of preparing sulfonimide or its salt

(CF.sub.3 SO.sub.2).sub.2 O is formed by reaction of CF.sub.3 SO.sub.3 H with P.sub.2 O.sub.5 and taken out of the reaction system by distillation, but the residue of the distillation contains a considerable amount of unreacted CF.sub.3 SO.sub.3 H. From the residue unreacted by adding water or a phosphoric acid solution, preferably the latter, to the residue to obtain a fluidic mixture containing an adequate amount of water and subjecting the mixture to distillation, preferably under reduced pressure at temperatures ranging from 180.degree. to 280.degree. C. It is possible to form additional CF.sub.3 SO.sub.3 H during the recovery process by adding a metal salt of CF.sub.3 SO.sub.3 H to the aformentioned mixture since the metal salt is decomposed by phosphoric acid contained in the mixture.

Method of preparing trifluoromethanesulfonic acid anhydride

A fluorocarbon carboxylic acid Rf(COOH).sub.m (Rf is C.sub.1 -C.sub.10 perfluoroalkyl group, m is 1 or 2) is prepared by the steps of hydrolyzing Rf(COF).sub.m with water to obtain an acidic solution, neutralizing the acidic solution with aqueous solution of KOH to form Rf(COOK).sub.m, precipitating and separating Rf(COOK).sub.m from the solution and converting Rf(COOK).sub.m into Rf(COOH).sub.m by acid decomposition. The content of free fluorine can extremely be reduced by treating Rf(COOK).sub.m with sulfuric acid and silica. The mother liquor is recycled after removing KF by treatment with a metal hydroxide and replenishing with KOH. In preparing a fluorocarbon sulfonic acid RfSO.sub.3 H (Rf is C.sub.1 -C.sub.3 perfluoroalkyl group) in substantially the same way, RfSO.sub.3 K is formed in aqueous solution of KOH by bringing gaseous RfSO.sub.2 F into contact with the KOH solution under normal pressure, while controlling the feed rate of RfSO.sub.2 F per unit area of gas-liquid contact at a sufficiently low level.

Process of preparing fluorocarbon carboxylic or sulfonic acid from its

In preparing a fluoroalkylsulfonate RfSO.sub.3 M, where Rf is a perfluoroalkyl gruop having not more than 6 carbon atoms and M is an alkali metal, by neutralization reaction between a fluoroalkylsulfonic acid RfSO.sub.3 H and an alkali metal carbonate or hydroxide, the reaction is carried out under acidic conditions such that at the end of the reaction pH of the reaction liquid is lower than 6, and preferably not higher than 3. By so maintaining the reaction liquid acidic, the obtained RfSO.sub.3 M becomes very low in the concentrations of anionic impurities such as free fluorine, free chlorine and carbonate radical and, besides becomes low in moisture absorbency.

Method of preparing alkali metal fluoroalkylsulfonates of high purity

A fluorine-containing high polymer, e.g. polytetrafluoroethylene, can easily and efficiently be converted into a wax-like lower molecular weight polymer by contact reaction of the high polymer with a gas comprising a fluorinating agent, which is selected from molecular fluorine, nitrogen-fluorine compounds represented by NF.sub.3, halogen fluorides represented by ClF.sub.3 and fluorides of rare gas elements represented by XeF.sub.2, at a temperature in the range from 250.degree. to 550.degree. C.

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Ube, Japan

Hiroaki Sakaguchi