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. 10, 1999
Filed:
Nov. 04, 1997
Brent Dellacoletta, Evansville, IN (US);
Roy Ray Odle, Mt. Vernon, IN (US);
Thomas L Guggenheim, Mt. Vernon, IN (US);
Ronald A Greenberg, Evansville, IN (US);
James P Barren, Scotia, NY (US);
Joseph A King, Schenectady, NY (US);
Sunita Singh Baghel, Rensselaer, NY (US);
Deborah A Haitko, Schenectady, NY (US);
David G Hawron, Clifton Park, NY (US);
General Electric Co., Pittsfield, MA (US);
Abstract
A process for making bis(ether anhydrides) employs alkylamines having low melting temperatures thus allowing for novel intermediate process steps for preparing bis(ether anhydrides). The alkylamines have alkyl groups which contain at least three carbon atoms and have boiling temperatures in the range of 48 to 250.degree. C. at atmospheric pressure. As a result of using these amines, liquid alkylamines now can be employed in the imidization process step. The N-alkyl nitrophthalimides prepared from the recovered imidization product according to this invention can now be purified using liquid/liquid extraction or vacuum distillation. The alkyl nitrophthalimides prepared according to this invention provide for displacement reactions which now can be run at a high solids level. Likewise, the exchange reaction can be run at a higher solids level, and thus achieves an efficiency level which is higher than conventional processes.