Granted Patent
Utility
US 4,997,958 · App. 07/321,948
Process for producing ascorbic acid 6-esters
Inventors:
Horst Pauling, Christof Wehrli
Patented Case
View Patent ↗
Granted: Mar 5, 1991
Filed: Mar 10, 1989
Inventors
Horst Pauling
Christof Wehrli
Assignee (at issue)
HOFFMANN-LA ROCHE 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.