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. 26, 1992
Filed:
Jul. 17, 1991
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
548457 ; 548458 ;
Abstract
A process for purifying indigo comprises stripping the as-synthesized aqueous alkaline indoxylate solution before its oxidation to indigo of impurities in the absence of oxygen by distillation or by passing in steam or an inert gas and then treating the indigo precipitated on oxidation of the stripped indoxylate solution with dilute hydrogen peroxide solution.
Kohlhaupt, Reinhold. (1992). Purification of indigo (U.S. Patent No. 5116996). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/5116996
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile