Granted Patent
Utility
US 5,229,448 · App. 07/713,942
Formation of filled molding powders of polybenzimidazole and other polymers
Inventor:
William M. Cooper
Patented Case
View Patent ↗
Granted: Jul 20, 1993
Filed: Jun 12, 1991
Inventor
William M. Cooper
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.