Granted Patent
Utility
US 5,641,549 · App. 08/572,382
Cellularized polyesters
Inventors:
Walter Francis Johnston, Donald E. Richeson, William G. Perkins
Patented Case
View Patent ↗
Granted: Jun 24, 1997
Filed: Dec 14, 1995
Inventors
Walter Francis Johnston
Donald E. Richeson
William G. Perkins
Assignee (at issue)
SHELL OIL 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.