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:
Nov. 25, 1986
Filed:
Dec. 20, 1984
Applicant:
Inventors:
Thomas L Evans, Schenectady, NY (US);
Marsha M Grade, Schenectady, NY (US);
Assignee:
General Electric Company, Schenectady, NY (US);
Primary Examiner:
Int. Cl.
CPC ...
C08G / ; C08G / ;
U.S. Cl.
CPC ...
528172 ; 528352 ;
Abstract
Aromatic sulfoxy tetracarboxylic acids, and their derivatives such as dianhydrides, bisimides and polyimides, are prepared by oxidizing the corresponding sulfides under relatively mild conditions, using oxidizing agents such as nitric acid, N-chlorosuccinimide, potassium persulfate and hydrogen peroxide. The polyimides may also be prepared by the reaction of the dianhydrides or certain bisimides with diamines.