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:
Aug. 04, 1987
Filed:
Nov. 29, 1984
UBE Industries, Ltd., , JP;
Abstract
A process for the preparation of a diazocyano acid, which comprises reacting a keto-acid or its sodium salt with a cyanogen compound such as sodium cyanide or hydrogen cyanide and a hydrazine in water to form a concentrated aqueous solution of a hydrazo compound, adding acetone or acetone and water to the concentrated aqueous solution to form an acetone-water solution of the hydrazo compound, adding an oxidant such as chlorine gas to the solution to oxidize the hydrazo compound and form a diazocyano acid, forming at least two transparent liquid layers by adding acetone and/or water to the obtained reaction mixture during or after oxidation if necessary, and further adding sodium chloride to the reaction mixture if necessary, and separating and recovering the upper layer of the acetone-water solution containing the diazocyano acid from the mixture.