Granted Patent
Utility
US 4,806,259 · App. 07/061,936
Membrane cleaning compositions containing phosphorous compounds
Inventor:
Zahid Amjad
Patented Case
View Patent ↗
Granted: Feb 21, 1989
Filed: Jun 15, 1987
Inventor
Zahid Amjad
Assignee (at issue)
B. F. Goodrich 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.