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. 07, 2012
Filed:
Jun. 27, 2007
Applicants:
Jean-claude Masson, Lyons, FR;
Philippe Carvin, Lyons, FR;
Jean-louis Grieneisen, Corbas, FR;
Inventors:
Assignee:
Rhodia Operations, Aubervilliers, FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C 37/84 (2006.01);
U.S. Cl.
CPC ...
Abstract
Hydroquinone devoid of impurities is prepared from a crude hydroquinone essentially containing hydroquinone and small amounts of impurities including at least resorcinol, pyrogallol and traces of pyrocatechol and comprises at least the following steps: dissolving the crude hydroquinone in water, crystallizing the hydroquinone, separating the purified hydroquinone, and, optionally, drying the purified hydroquinone.