Granted Patent
Utility
US 5,856,421 · App. 08/818,987
Polyetherimide preparation method including addition of macrocyclic polyetherimide oligomers
Inventor:
John Schmidhauser
Patented Case
View Patent ↗
Granted: Jan 5, 1999
Filed: Mar 17, 1997
Inventor
John Schmidhauser
Assignee (at issue)
General Electric Company
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.