Granted Patent
Utility
US 4,941,537 · App. 07/371,651
Method for reducing the viscosity of aqueous fluid
Inventors:
Paul W. Langemeier, Martha A. Phelps, Michael E. Morgan
Patented Case
View Patent ↗
Granted: Jul 17, 1990
Filed: Jun 22, 1989
Inventors
Paul W. Langemeier
Martha A. Phelps
Michael E. Morgan
Assignee (at issue)
Hi-Tek Polymers, Inc.
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.