The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 26, 2001
Filed:
Feb. 15, 2000
Central Glass Company, Limited, Ube, JP;
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.