Abstract: The invention relates to a process for producing an alkali metal salt of a perfluoroalkanesulfinic acid. This process includes the step of bringing a perfluoroalkanesulfonic fluoride into contact with an alkali metal salt of sulfurous acid in the presence of water. This process is useful, since this perfluoroalkanesulfonic fluoride (e.g., trifluoromethanesulfonic fluoride) is easily available.

Abstract: 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.

Abstract: The present invention provides a method for producing trifluoromethanesulfonyl chloride. This method includes the step of reacting trifluoromethanesulfonic acid with phosphorous trichloride and chlorine. With this method, trifluoromethanesulfonyl chloride can be easily and highly selectively produced at high yield. The reaction may be carried out at about atmospheric pressure. Furthermore, the reaction may be carried out in the presence of phosphorus oxychloride either under a pressurized condition or at about atmospheric pressure.

Abstract: 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.

Abstract: A method and a device for finishing the cut surface of a work which is cut from a metal blank by a wire cut discharge process. The work and the waste piece of the metal blank are positioned in the same condition as just after the process. Electrolyte is fed through a clearance between the work and the waste piece and, at the same time, current is caused to flow from the work to the remainder. This subjects the cut surface of the work to electrolytic treatment to thereby make it smooth while removing oxide films and degenerated surface layers therefrom.

Abstract: In a method of repairing a semiconductor memory device having spare lines, all possible solutions of remedy using spare lines or spare blocks are obtained based on the result of test for the device, and then the possible solutions are screened under conditions related to the quality and reliability of the device so as to determine the best solution.