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:
Sep. 06, 2011
Filed:
Mar. 28, 2008
Beatriz Penalver Bernabe, Chicago, IL (US);
Vijay Gopalakrishnan, Evansville, IN (US);
Lioba Maria Kloppenburg, Mount Vernon, IN (US);
Matt Kuhlman, Evansville, IN (US);
Roy Ray Odle, Mount Vernon, IN (US);
Eric Pressman, East Greenbush, NY (US);
Narayan Ramesh, Evansville, IN (US);
Harpreet Singh, Evansville, IN (US);
Beatriz Penalver Bernabe, Chicago, IL (US);
Vijay Gopalakrishnan, Evansville, IN (US);
Lioba Maria Kloppenburg, Mount Vernon, IN (US);
Matt Kuhlman, Evansville, IN (US);
Roy Ray Odle, Mount Vernon, IN (US);
Eric Pressman, East Greenbush, NY (US);
Narayan Ramesh, Evansville, IN (US);
Harpreet Singh, Evansville, IN (US);
Abstract
A method for purifying an oxydiphthalic anhydride comprises diluting a first mixture comprising an oxydiphthalic anhydride, a solvent, a catalyst, and an inorganic salt with a solvent, to provide a second mixture having a solids content of 10 to 30 percent based on total weight of the second mixture; filtering and washing the solids of the second mixture at a temperature below the crystallization point temperature of the oxydiphthalic anhydride to provide a third mixture; hydrolyzing the third mixture by adding water and a water-soluble acid to form a fourth mixture; heating the fourth mixture; then cooling to provide a solid-liquid mixture, optionally decanting a portion of the liquid, rediluting the remaining solid-liquid mixture, then filtering to provide a solid component; washing the solid component with water to provide a fifth mixture of oxydiphthalic tetraacid and water; ring closing the oxydiphthalic tetraacid to provide oxydiphthalic anhydride, and filtering the oxydiphthalic anhydride.