Granted Patent
Utility
US 4,631,252 · App. 06/741,888
Hydroquinone ether compounds
Inventor:
Frederick H. Howell
Patented Case
View Patent ↗
Granted: Dec 23, 1986
Filed: Jun 6, 1985
Inventor
Frederick H. Howell
Assignee (at issue)
Ciba-Geigy
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.