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:
Mar. 27, 1979
Filed:
Dec. 15, 1976
Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, JP;
Abstract
A method for obtaining glutaric acid, succinic acid, and adipic acid from an acid mixture obtained as a by-product in the industry and comprising glutaric acid, succinic acid and adipic acid, which comprises the steps of: (1) contacting the acid mixture with urea of 1 to 2 moles per mole of the acid mixture, in solution, to deposit a urea-glutaric acid adduct so that the weight ratio of glutaric acid remaining in the solution to succinic acid is 1.2 or less when the adipic acid content is in the range of 0% by weight to 7% by weight and 1.4 or less when the adipic acid content is larger than 7% by weight and 30% by weight or less; separating the deposited urea-glutaric acid adduct out of the solution; (2) adding further urea to the solution and/or concentrating the solution obtained in the step (1) to deposit a urea-succinic acid adduct; separating the deposited urea-succinic acid adduct out of the solution; and (3) decomposing the separated urea-dicarboxylic acid adducts each into respective dicarboxylic acids and urea. With this method, the mixture comprising glutaric acid, succinic acid and adipic acid can, for the first time, be successfully and effectively separated into the respective components.