Granted Patent
Utility
US 5,021,168 · App. 07/381,345
Process for the preparation and recovery of oxydiphthalic anhydrides
Inventors:
John R. Molinaro, Joseph A. Pawlak, Willis T. Schwartz
Patented Case
View Patent ↗
Granted: Jun 4, 1991
Filed: Jul 18, 1989
Inventors
John R. Molinaro
Joseph A. Pawlak
Willis T. Schwartz
Assignee (at issue)
Occidental Chemical 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.