Granted Patent
Utility
US 4,980,447 · App. 07/321,021
Polyamide-polyimide and polybenzoxazole-polyimide polymer
Inventor:
Dinesh N. Khanna
Patented Case
View Patent ↗
Granted: Dec 25, 1990
Filed: Mar 9, 1989
Inventor
Dinesh N. Khanna
Assignee (at issue)
Hoechst Celanese Corporation
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.