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:
Feb. 11, 2003
Filed:
Oct. 31, 2000
Applicant:
Inventor:
Jean-Pierre Schirmann, Oullins, FR;
Assignee:
Atofino, Paris, FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01B 2/116 ; C07C 4/542 ;
U.S. Cl.
CPC ...
C01B 2/116 ; C07C 4/542 ;
Abstract
The invention concerns a method for making hydrazine hydrate which consists in hydrolyzing methyl ethyl ketone azine to obtain hydrazine hydrate and methyl ethyl ketone, characterised in that it consists in purging heterocyclic compounds of the pyrazoline family to prevent coloration of the hydrazine hydrate.