Granted Patent
Utility
US 6,222,008 · App. 09/518,437
Treatment of polymer solution with acid and ammonia to improve polymer color
Inventor:
Richard Gelles
Patented Case
View Patent ↗
Granted: Apr 24, 2001
Filed: Mar 2, 2000
Inventor
Richard Gelles
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.