Granted Patent
Utility
US 5,087,771 · App. 07/622,453
Process for the purification of monotertiarybutyl hydroquinone
Inventor:
James R. Hilderbrand
Patented Case
View Patent ↗
Granted: Feb 11, 1992
Filed: Dec 5, 1990
Inventor
James R. Hilderbrand
Assignee (at issue)
EASTMAN KODAK 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.