Granted Patent
Utility
US 4,983,186 · App. 07/381,232
Methods and compositions for reduction of drag in hydrocarbon fluids
Inventors:
Michael I. Naiman, James Chang
Patented Case
View Patent ↗
Granted: Jan 8, 1991
Filed: Jul 18, 1989
Inventors
Michael I. Naiman
James Chang
Assignee (at issue)
Petrolite Corporation
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.