Granted Patent
Utility
US 5,288,930 · App. 08/089,611
Purification of 1,1,1,2-tetrafluoroethane
Inventors:
Charles John Shields, Adrian S. Swindells
Patented Case
View Patent ↗
Granted: Feb 22, 1994
Filed: Jul 12, 1993
Inventors
Charles John Shields
Adrian S. Swindells
Assignee (at issue)
IMPERIAL CHEMICAL INDUSTRIES LIMITED
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.