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:
Jul. 13, 2010
Filed:
Jan. 14, 2005
Stephan Führer, Kastl, DE;
Klaus Hintzer, Kastl, DE;
Gernot Löhr, Burgkirchen, DE;
Egon Obermaier, Taubenbach, DE;
Werner Schwertfeger, Altoetting, DE;
Stephan Führer, Kastl, DE;
Klaus Hintzer, Kastl, DE;
Gernot Löhr, Burgkirchen, DE;
Egon Obermaier, Taubenbach, DE;
Werner Schwertfeger, Altoetting, DE;
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
The present invention provides a method of recovering a fluorinated acid surfactant or salt thereof from adsorbent particles to which said fluorinated acid surfactant has been adsorbed. The method comprises mixing adsorbent particles having adsorbed fluorinated acid surfactant or salt thereof with an alcohol and optionally an acid. The mixture is generally heated to cause esterification of the fluorinated acid surfactant or salt thereof with the alcohol so as to form an ester derivative of the fluorinated acid surfactant, distilling the mixture to form a distillate comprising the ester derivative, separating the ester derivative from the distillate and optionally feeding the remainder of the distillate back into the mixture.