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:
May. 12, 1998
Filed:
Mar. 11, 1997
Showa Denko K.K., Tokyo, JP;
Abstract
The present invention provides a method for producing N-phosphonomethylglycine which comprises reacting an aminomethylphosphonic acid with glycolonitrile, or formaldehyde and hydrogen cyanide in situ, under an alkaline condition to convert the aminomethylphosphonic acid into an N-phosphonomethylglycinonitrile salt or a mixture of an N-phosphonomethylglycinonitrile salt and N-phosphonomethylglycinonitrile, and then hydrolyzing the product under an acidic condition. Subsequent to a reaction step for the production of N-phosphonomethylglycinonitrile, the reaction product is hydrolyzed by adding thereto an acid in a prescribed amount. Accordingly, the use of a large amount of an alkaline metal hydroxide and the neutralization step for obtaining N-phosphonomethylglycine after hydrolysis, which steps are necessary in a conventional alkali hydrolysis method, are omitted in the present invention.