Granted Patent
Utility
US 4,316,807 · App. 05/892,543
Viscosifying agent
Inventors:
Carl V. McDaniel, Nelson S. Marans
Patented Case
View Patent ↗
Granted: Feb 23, 1982
Filed: Apr 3, 1978
Inventors
Carl V. McDaniel
Nelson S. Marans
Assignee (at issue)
W. R. Grace & 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.