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. 09, 2011
Filed:
Jul. 07, 2009
Lutz Brassat, Leverkusen, DE;
Stephan Kirchmeyer, Leverkusen, DE;
Lutz Brassat, Leverkusen, DE;
Stephan Kirchmeyer, Leverkusen, DE;
H. C. Starck GmbH, , DE;
Abstract
The invention relates to a process for the purification of thiophenes by means of precipitation. The purified thiophenes are liquid at room temperature, have a purity of at least 99.50 wt. %, and are represented by the following general formula (I), wherein Rand Rindependently of each other are, for example, a linear or branched C-C-alkyl group, or together form a fused C-C-dioxyalylene ring. The process involves: (I) precipitating the thiophene by cooling a solution of the thiophene and at least one solvent; or (II) precipitating the thiophene by adding the thiophene to a cooled solution of solvent and optionally the thiophene. The solutions are cooled to a temperature below the melting point of the thiophene.