Granted Patent
Utility
US 4,820,829 · App. 07/001,309
Substituted o-phthalaldehydes
Inventor:
Alfred Steinmann
Patented Case
View Patent ↗
Granted: Apr 11, 1989
Filed: Jan 8, 1987
Inventor
Alfred Steinmann
Assignee (at issue)
Ciba-Geigy
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.