Granted Patent
Utility
US 5,508,137 · App. 08/287,400
Perylene amidine imide dyes, a process for preparing them, and their use
Inventor:
Heinz Langhals
Patented Case
View Patent ↗
Granted: Apr 16, 1996
Filed: Aug 8, 1994
Inventor
Heinz Langhals
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.