Granted Patent
Utility
US 4,994,577 · App. 07/402,413
Quaternized silicones
Inventors:
Mohamed M. Hashem, James H. Merrifield
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Sep 5, 1989
Inventors
Mohamed M. Hashem
James H. Merrifield
Assignee (at issue)
Rhone-Poulenc Specialty Chemicals Co.
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.